Abstract:
The object to provide a highly-integrated SGT-based SRAM is achieved by forming an SRAM using an inverter which comprises a first island-shaped semiconductor layer, a first gate dielectric film in contact with a periphery of the first island-shaped semiconductor layer, a first gate electrode having one surface in contact with the first gate dielectric film, a second gate dielectric film in contact with another surface of the first gate electrode, a first arc-shaped semiconductor layer in contact with the second gate dielectric film, a first first-conductive-type high-concentration semiconductor layer arranged on a top of the first island-shaped semiconductor layer, a second first-conductive-type high-concentration semiconductor layer arranged underneath the first island-shaped semiconductor layer, a first second-conductive-type high-concentration semiconductor layer arranged on a top of the first arc-shaped semiconductor layer, and a second second-conductive-type high-concentration semiconductor layer arranged underneath the first arc-shaped semiconductor layer.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of Japanese Patent Application No. 2009-135754 filed on Jun. 5, 2009 and U.S. Provisional Application No. 61/268,195 filed on Jun. 9, 2009, the entire disclosure of which is incorporated by reference herein. 
     
    
     FIELD 
       [0002]    The present invention relates to a semiconductor device. 
       BACKGROUND 
       [0003]    A degree of integration in a semiconductor device, particularly in an integrated circuit using a MOS transistor, has been increasing year by year. Along with the increase in the degree of integration, miniaturization of the MOS transistor used therein has progressed to a nano region. The progress in miniaturization of the MOS transistor, which constitutes an inverter circuit as a basic circuit for digital circuits, gives rise to a problem, such as difficulty in suppressing a leak current, which causes deterioration in reliability due to hot carrier effects and poses an impediment to sufficiently reducing a circuit occupancy area while meeting a requirement of ensuring a necessary current magnitude. With a view to solving this problem, there have been proposed a surrounding gate transistor (SGT) having a structure in which a source, a gate and a drain are arranged in a direction perpendicular to a substrate, wherein the gate is formed to surround an island-shaped semiconductor layer, and a CMOS inverter circuit using the SGT (see, for example, S. Watanabe, K. Tsuchida, D. Takashima, Y. Oowaki, A. Nitayama, K. Hieda, H. Takato, K. Sunouchi, F. Horiguchi, K. Ohuchi, F. Masuoka, H. Hara, “A Novel Circuit Technology with Surrounding Gate Transistors (SGT&#39;s) for Ultra High Density DRAM&#39;s,” IEEE JSSC, Vol. 30, No. 9, 1995). 
         [0004]    An inverter is constructed using a pMOS transistor and an nMOS transistor. In an inverter circuit, a gate width of a pMOS transistor has to be set to be twice as large as that of an nMOS transistor, because a hole mobility is one-half of an electron mobility. Therefore, a conventional CMOS inverter circuit using an SGT (SGT CMOS inverter circuit) is composed of two pMOS SGTs and one nMOS SGT. In other words, the conventional SGT CMOS inverter circuit is composed of total three island-shaped semiconductors. 
         [0005]    An SRAM is composed of two inverters and two selection transistors. In cases where an SRAM is constructed using the conventional SGT CMOS inverter circuit, it is composed of four pMOS and four nMOS. In other words, the SRAM using the conventional SGT CMOS inverter circuit is composed of total eight island-shaped semiconductors. 
       SUMMARY 
       [0006]    It is therefore an object of the present invention to provide a semiconductor device comprising a highly-integrated SGT-based SRAM. 
         [0007]    In order to achieve this object, according to a first aspect of the present invention, there is provided a semiconductor device which comprises: a first inverter arranged at an intersection of the 1st row and the 1st column, wherein the first inverter includes a first island-shaped semiconductor layer, a first gate dielectric film in contact with at least a part of a periphery of the first island-shaped semiconductor layer, a first gate electrode having one surface in contact with the first gate dielectric film, a second gate dielectric film in contact with another surface of the first gate electrode, a first arc-shaped semiconductor layer in contact with at least a part of the second gate dielectric film, a first first-conductive-type high-concentration semiconductor layer arranged on a top of the first island-shaped semiconductor layer, a second first-conductive-type high-concentration semiconductor layer arranged underneath the first island-shaped semiconductor layer, a first second-conductive-type high-concentration semiconductor layer arranged on a top of the first arc-shaped semiconductor layer, and a second second-conductive-type high-concentration semiconductor layer arranged underneath the first arc-shaped semiconductor layer; a second inverter arranged at an intersection of the 2nd row and the 2nd column, wherein the second inverter includes a second island-shaped semiconductor layer, a third gate dielectric film in contact with at least a part of a periphery of the second island-shaped semiconductor layer, a second gate electrode having one surface in contact with the third gate dielectric film, a fourth gate dielectric film in contact with another surface of the second gate electrode, a second arc-shaped semiconductor layer in contact with at least a part of the fourth gate dielectric film, a third first-conductive-type high-concentration semiconductor layer arranged on a top of the second island-shaped semiconductor layer, a fourth first-conductive-type high-concentration semiconductor layer arranged underneath the second island-shaped semiconductor layer, a third second-conductive-type high-concentration semiconductor layer arranged on a top of the second arc-shaped semiconductor layer, and a fourth second-conductive-type high-concentration semiconductor layer arranged underneath the second arc-shaped semiconductor layer; a first selection transistor arranged at an intersection of the 1st row and the 2nd column, wherein the first selection transistor includes a third island-shaped semiconductor layer, a fifth gate dielectric film in contact with at least a part of a periphery of the third island-shaped semiconductor layer, a third gate electrode partially in contact with the fifth gate dielectric film, a fifth second-conductive-type high-concentration semiconductor layer arranged on a top of the third island-shaped semiconductor layer, and a sixth second-conductive-type high-concentration semiconductor layer arranged underneath the third island-shaped semiconductor layer; and a second selection transistor arranged at an intersection of the 2nd row and the 1st column, wherein the second selection transistor includes a fourth island-shaped semiconductor layer, a sixth gate dielectric film in contact with at least a part of a periphery of the fourth island-shaped semiconductor layer, a fourth gate electrode partially in contact with the sixth gate dielectric film, a seventh second-conductive-type high-concentration semiconductor layer arranged on a top of the fourth island-shaped semiconductor layer, and an eighth second-conductive-type high-concentration semiconductor layer arranged underneath the fourth island-shaped semiconductor layer. 
         [0008]    According to a second aspect of the present invention, there is provided a semiconductor device which comprises: a first inverter arranged at an intersection of the 1st row and the 1st column, wherein the first inverter includes a first island-shaped semiconductor layer, a first gate dielectric film surrounding a periphery of the first island-shaped semiconductor layer, a first gate electrode surrounding a periphery of the first gate dielectric film, a second gate dielectric film surrounding a part of a periphery of the first gate electrode, a first arc-shaped semiconductor layer in contact with a part of a periphery of the second gate dielectric film, a first first-conductive-type high-concentration semiconductor layer arranged on a top of the first island-shaped semiconductor layer, a second first-conductive-type high-concentration semiconductor layer arranged underneath the first island-shaped semiconductor layer, a first second-conductive-type high-concentration semiconductor layer arranged on a top of the first arc-shaped semiconductor layer, and a second second-conductive-type high-concentration semiconductor layer arranged underneath the first arc-shaped semiconductor layer; a second inverter arranged at an intersection of the 2nd row and the 2nd column, wherein the second inverter includes a second island-shaped semiconductor layer, a third gate dielectric film surrounding a periphery of the second island-shaped semiconductor layer, a second gate electrode surrounding a periphery of the third gate dielectric film, a fourth gate dielectric film surrounding a part of a periphery of the second gate electrode, a second arc-shaped semiconductor layer in contact with a part of a periphery of the fourth gate dielectric film, a third first-conductive-type high-concentration semiconductor layer arranged on a top of the second island-shaped semiconductor layer, a fourth first-conductive-type high-concentration semiconductor layer arranged underneath the second island-shaped semiconductor layer, a third second-conductive-type high-concentration semiconductor layer arranged on a top of the second arc-shaped semiconductor layer, and a fourth second-conductive-type high-concentration semiconductor layer arranged underneath the second arc-shaped semiconductor layer; a first selection transistor arranged at an intersection of the 1st row and the 2nd column, wherein the first selection transistor includes a third island-shaped semiconductor layer, a fifth gate dielectric film surrounding a periphery of the third island-shaped semiconductor layer, a third gate electrode surrounding a periphery of the fifth gate dielectric film, a fifth second-conductive-type high-concentration semiconductor layer arranged on a top of the third island-shaped semiconductor layer, and a sixth second-conductive-type high-concentration semiconductor layer arranged underneath the third island-shaped semiconductor layer; and a second selection transistor arranged at an intersection of the 2nd row and the 1st column, wherein the second selection transistor includes a fourth island-shaped semiconductor layer, a sixth gate dielectric film surrounding a periphery of the fourth island-shaped semiconductor layer, a fourth gate electrode surrounding a periphery of the sixth gate dielectric film, a seventh second-conductive-type high-concentration semiconductor layer arranged on a top of the fourth island-shaped semiconductor layer, and an eighth second-conductive-type high-concentration semiconductor layer arranged underneath the fourth island-shaped semiconductor layer. 
         [0009]    According to a third aspect of the present invention, there is provided a semiconductor device which comprises: a first inverter arranged at an intersection of the 1st row and the 1st column, wherein the first inverter includes a first island-shaped semiconductor layer, a first gate dielectric film surrounding a periphery of the first island-shaped semiconductor layer, a first gate electrode surrounding a periphery of the first gate dielectric film, a second gate dielectric film surrounding a part of a periphery of the first gate electrode, a first arc-shaped semiconductor layer in contact with a part of a periphery of the second gate dielectric film, a first first-conductive-type high-concentration semiconductor layer arranged on a top of the first island-shaped semiconductor layer, a second first-conductive-type high-concentration semiconductor layer arranged underneath the first island-shaped semiconductor layer, a first second-conductive-type high-concentration semiconductor layer arranged on a top of the first arc-shaped semiconductor layer, and a second second-conductive-type high-concentration semiconductor layer arranged underneath the first arc-shaped semiconductor layer; a second inverter arranged at an intersection of the 2nd row and the 2nd column, wherein the second inverter includes a second island-shaped semiconductor layer, a third gate dielectric film surrounding a periphery of the second island-shaped semiconductor layer, a second gate electrode surrounding a periphery of the third gate dielectric film, a fourth gate dielectric film surrounding a part of a periphery of the second gate electrode, a second arc-shaped semiconductor layer in contact with a part of a periphery of the fourth gate dielectric film, a third first-conductive-type high-concentration semiconductor layer arranged on a top of the second island-shaped semiconductor layer, a fourth first-conductive-type high-concentration semiconductor layer arranged underneath the second island-shaped semiconductor layer, a third second-conductive-type high-concentration semiconductor layer arranged on a top of the second arc-shaped semiconductor layer, and a fourth second-conductive-type high-concentration semiconductor layer arranged underneath the second arc-shaped semiconductor layer; a first selection transistor arranged at an intersection of the 1st row and the 2nd column, wherein the first selection transistor includes a third island-shaped semiconductor layer, a fifth gate dielectric film surrounding a periphery of the third island-shaped semiconductor layer, a third gate electrode surrounding a periphery of the fifth gate dielectric film, a fifth second-conductive-type high-concentration semiconductor layer arranged on a top of the third island-shaped semiconductor layer, and a sixth second-conductive-type high-concentration semiconductor layer arranged underneath the third island-shaped semiconductor layer; a second selection transistor arranged at an intersection of the 2nd row and the 1st column, wherein the second selection transistor includes a fourth island-shaped semiconductor layer, a sixth gate dielectric film surrounding a periphery of the fourth island-shaped semiconductor layer, a fourth gate electrode surrounding a periphery of the sixth gate dielectric film, a seventh second-conductive-type high-concentration semiconductor layer arranged on a top of the fourth island-shaped semiconductor layer, and an eighth second-conductive-type high-concentration semiconductor layer arranged underneath the fourth island-shaped semiconductor layer; a fifth first-conductive-type high-concentration semiconductor layer arranged underneath the second first-conductive-type high-concentration semiconductor layer, the second second-conductive-type high-concentration semiconductor layer and the eighth second-conductive-type high-concentration semiconductor layer; a sixth first-conductive-type high-concentration semiconductor layer arranged underneath the fourth first-conductive-type high-concentration semiconductor layer, the fourth second-conductive-type high-concentration semiconductor layer and the sixth second-conductive-type high-concentration semiconductor layer; a first semiconductor-metal compound layer formed on a part of respective sidewalls of the second second-conductive-type high-concentration semiconductor layer and the fifth first-conductive-type high-concentration semiconductor layer; a second semiconductor-metal compound layer formed on the eighth second-conductive-type high-concentration semiconductor layer and the fifth first-conductive-type high-concentration semiconductor layer; a third semiconductor-metal compound layer formed on a part of respective sidewalls of the fourth second-conductive-type high-concentration semiconductor layer and the sixth first-conductive-type high-concentration semiconductor layer; a fourth semiconductor-metal compound layer formed on the sixth second-conductive-type high-concentration semiconductor layer and the sixth first-conductive-type high-concentration semiconductor layer; a fifth semiconductor-metal compound layer formed on the first first-conductive-type high-concentration semiconductor layer; a sixth semiconductor-metal compound layer formed on the first second-conductive-type high-concentration semiconductor layer; a seventh semiconductor-metal compound layer formed on the third first-conductive-type high-concentration semiconductor layer; an eighth semiconductor-metal compound layer formed on the third second-conductive-type high-concentration semiconductor layer; a ninth semiconductor-metal compound layer formed on the fifth second-conductive-type high-concentration semiconductor layer; a tenth semiconductor-metal compound layer formed on the seventh second-conductive-type high-concentration semiconductor layer; a first contact connecting the first gate electrode and the fourth semiconductor-metal compound layer; and a second contact connecting the second gate electrode and the second semiconductor-metal compound layer. 
         [0010]    According to a fourth aspect of the present invention, there is provided a semiconductor device which comprises: a first inverter arranged at an intersection of the 1st row and the 1st column, wherein the first inverter includes a first island-shaped semiconductor layer, a first gate dielectric film surrounding a periphery of the first island-shaped semiconductor layer, a first gate electrode surrounding a periphery of the first gate dielectric film, a second gate dielectric film surrounding a part of a periphery of the first gate electrode, a first arc-shaped semiconductor layer in contact with a part of a periphery of the second gate dielectric film, a first p+-type semiconductor layer arranged on a top of the first island-shaped semiconductor layer, a second p+-type semiconductor layer arranged underneath the first island-shaped semiconductor layer, a first n+-type semiconductor layer arranged on a top of the first arc-shaped semiconductor layer and a second n+-type semiconductor layer arranged underneath the first arc-shaped semiconductor layer; a second inverter arranged at an intersection of the 2nd row and the 2nd column, wherein the second inverter includes a second island-shaped semiconductor layer, a third gate dielectric film surrounding a periphery of the second island-shaped semiconductor layer, a second gate electrode surrounding a periphery of the third gate dielectric film, a fourth gate dielectric film surrounding a part of a periphery of the second gate electrode, a second arc-shaped semiconductor layer in contact with a part of a periphery of the fourth gate dielectric film, a third p+-type semiconductor layer arranged on a top of the second island-shaped semiconductor layer, a fourth p+-type semiconductor layer arranged underneath the second island-shaped semiconductor layer, a third n+-type semiconductor layer arranged on a top of the second arc-shaped semiconductor layer, and a fourth n+-type semiconductor layer arranged underneath the second arc-shaped semiconductor layer; a first selection transistor arranged at an intersection of the 1st row and the 2nd column, wherein the first selection transistor includes a third island-shaped semiconductor layer, a fifth gate dielectric film surrounding a periphery of the third island-shaped semiconductor layer, a third gate electrode surrounding a periphery of the fifth gate dielectric film, a fifth n+-type semiconductor layer arranged on a top of the third island-shaped semiconductor layer, and a sixth n+-type semiconductor layer arranged underneath the third island-shaped semiconductor layer; and a second selection transistor arranged at an intersection of the 2nd row and the 1st column, wherein the second selection transistor includes a fourth island-shaped semiconductor layer, a sixth gate dielectric film surrounding a periphery of the fourth island-shaped semiconductor layer, a fourth gate electrode surrounding a periphery of the sixth gate dielectric film, a seventh n+-type semiconductor layer arranged on a top of the fourth island-shaped semiconductor layer, and an eighth n+-type semiconductor layer arranged underneath the fourth island-shaped semiconductor layer. 
         [0011]    According to a fifth aspect of the present invention, there is provided a semiconductor device which comprises: a first inverter arranged at an intersection of the 1st row and the 1st column, wherein the first inverter includes a first island-shaped semiconductor layer, a first gate dielectric film surrounding a periphery of the first island-shaped semiconductor layer, a first gate electrode surrounding a periphery of the first gate dielectric film, a second gate dielectric film surrounding a part of a periphery of the first gate electrode, a first arc-shaped semiconductor layer in contact with a part of a periphery of the second gate dielectric film, a first p+-type semiconductor layer arranged on a top of the first island-shaped semiconductor layer, a second p+-type semiconductor layer arranged underneath the first island-shaped semiconductor layer, a first n+-type semiconductor layer arranged on a top of the first arc-shaped semiconductor layer and a second n+-type semiconductor layer arranged underneath the first arc-shaped semiconductor layer; a second inverter arranged at an intersection of the 2nd row and the 2nd column, wherein the second inverter includes a second island-shaped semiconductor layer, a third gate dielectric film surrounding a periphery of the second island-shaped semiconductor layer, a second gate electrode surrounding a periphery of the third gate dielectric film, a fourth gate dielectric film surrounding a part of a periphery of the second gate electrode, a second arc-shaped semiconductor layer in contact with a part of a periphery of the fourth gate dielectric film, a third p+-type semiconductor layer arranged on a top of the second island-shaped semiconductor layer, a fourth p+-type semiconductor layer arranged underneath the second island-shaped semiconductor layer, a third n+-type semiconductor layer arranged on a top of the second arc-shaped semiconductor layer, and a fourth n+-type semiconductor layer arranged underneath the second arc-shaped semiconductor layer; a first selection transistor arranged at an intersection of the 1st row and the 2nd column, wherein the first selection transistor includes a third island-shaped semiconductor layer, a fifth gate dielectric film surrounding a periphery of the third island-shaped semiconductor layer, a third gate electrode surrounding a periphery of the fifth gate dielectric film, a fifth n+-type semiconductor layer arranged on a top of the third island-shaped semiconductor layer, and a sixth n+-type semiconductor layer arranged underneath the third island-shaped semiconductor layer; a second selection transistor arranged at an intersection of the 2nd row and the 1st column, wherein the second selection transistor includes a fourth island-shaped semiconductor layer, a sixth gate dielectric film surrounding a periphery of the fourth island-shaped semiconductor layer, a fourth gate electrode surrounding a periphery of the sixth gate dielectric film, a seventh n+-type semiconductor layer arranged on a top of the fourth island-shaped semiconductor layer, and an eighth n+-type semiconductor layer arranged underneath the fourth island-shaped semiconductor layer; a fifth p+-type semiconductor layer arranged underneath the second p+-type semiconductor layer, the second n+-type semiconductor layer and the eighth n+-type semiconductor layer; a sixth p+-type semiconductor layer arranged underneath the fourth p+-type semiconductor layer, the fourth n+-type semiconductor layer and the sixth n+-type semiconductor layer; a first semiconductor-metal compound layer formed on a part of respective sidewalls of the second n+-type semiconductor layer and the fifth p+-type semiconductor layer; a second semiconductor-metal compound layer formed on the eighth n+-type semiconductor layer and the fifth p+-type semiconductor layer; a third semiconductor-metal compound layer formed on a part of respective sidewalls of the fourth n+-type semiconductor layer and the sixth p+-type semiconductor layer; a fourth semiconductor-metal compound layer formed on the sixth n+-type semiconductor layer and the sixth p+-type semiconductor layer; a fifth semiconductor-metal compound layer formed on the first p+-type semiconductor layer; a sixth semiconductor-metal compound layer formed on the first n+-type semiconductor layer; a seventh semiconductor-metal compound layer formed on the third p+-type semiconductor layer; an eighth semiconductor-metal compound layer formed on the third n+-type semiconductor layer; a ninth semiconductor-metal compound layer formed on the fifth n+-type semiconductor layer; a tenth semiconductor-metal compound layer formed on the seventh n+-type semiconductor layer; a first contact connecting the first gate electrode and the fourth semiconductor-metal compound layer; and a second contact connecting the second gate electrode and the second semiconductor-metal compound layer. 
         [0012]    Preferably, the semiconductor device of the present invention is configured to satisfy the following condition: Wp 1 ≈2 Wn 1 , wherein Wp 1  is an outer peripheral length of the first island-shaped semiconductor layer, and Wn 1  is a length of an arc of the first arc-shaped semiconductor layer in contact with a part of the periphery of the second gate dielectric film. 
         [0013]    Preferably, the semiconductor device of the present invention is configured to satisfy the following condition: Wp 2 ≈2 Wn 2 , wherein Wp 2  is an outer peripheral length of the second island-shaped semiconductor layer, and Wn 2  is a length of an arc of the second arc-shaped semiconductor layer in contact with a part of the periphery of the fourth gate dielectric film. 
         [0014]    Preferably, the semiconductor device of the present invention is configured to satisfy the following condition: Ln 1 ≈Lp 1 , wherein Ln 1  is a channel length of the first arc-shaped semiconductor layer, and Lp 1  is a channel length of the first island-shaped semiconductor layer. 
         [0015]    Preferably, the semiconductor device of the present invention is configured to satisfy the following condition: Ln 2 ≈Lp 2 , wherein Ln 2  is a channel length of the second arc-shaped semiconductor layer, and Lp 2  is a channel length of the second island-shaped semiconductor layer. 
         [0016]    Preferably, in the semiconductor device of the present invention, a first pMOS transistor, a first nMOS transistor, a second pMOS transistor and a second nMOS transistor are made up of a combination of the first island-shaped semiconductor layer, the first gate dielectric film surrounding the periphery of the first island-shaped semiconductor layer, the first gate electrode surrounding the periphery of the first gate dielectric film, the first p+-type semiconductor layer arranged on the top of the first island-shaped semiconductor layer, and the second p+-type semiconductor layer arranged underneath the first island-shaped semiconductor layer, a combination of the first gate electrode, the second gate dielectric film surrounding a part of the periphery of the first gate electrode, the first arc-shaped semiconductor layer in contact with a part of a periphery of the second gate dielectric film, a first n+-type semiconductor layer arranged on the top of the first arc-shaped semiconductor layer, and the second n+-type semiconductor layer arranged underneath the first arc-shaped semiconductor layer, a combination of the second island-shaped semiconductor layer, the third gate dielectric film surrounding the periphery of the second island-shaped semiconductor layer, the second gate electrode surrounding the periphery of the third gate dielectric film, the third p+-type semiconductor layer arranged on the top of the second island-shaped semiconductor layer, and the fourth p+-type semiconductor layer arranged underneath the second island-shaped semiconductor layer, and a combination of the second gate electrode, the fourth gate dielectric film surrounding a part of the periphery of the second gate electrode, the second arc-shaped semiconductor layer in contact with a part of the periphery of the fourth gate dielectric film, the third n+-type semiconductor layer arranged on the top of the second arc-shaped semiconductor layer, and the fourth n+-type semiconductor layer arranged underneath the second arc-shaped semiconductor layer, respectively, wherein: the first gate dielectric film is adapted to allow the first pMOS transistor to operate as an enhancement type; the second gate dielectric film is adapted to allow the first nMOS transistor to operate as an enhancement type; the first electrode is made of a material allowing the first pMOS transistor and the first nMOS transistor to operate as an enhancement type; the third gate dielectric film is adapted to allow the second nMOS transistor to operate as an enhancement type, and the first electrode is made of a material allowing the second pMOS transistor and the second nMOS transistor to operate as an enhancement type. 
         [0017]    Preferably, in the semiconductor device according to the fifth aspect of the present invention, each of the first to tenth semiconductor-metal compound layers is a silicon-metal compound layer. 
         [0018]    In the semiconductor device of the present invention, the first island-shaped semiconductor layer, the first arc-shaped semiconductor layer, the second island-shaped semiconductor layer, the second arc-shaped semiconductor layer, the third island-shaped semiconductor layer and the fourth island-shaped semiconductor layer may be a first island-shaped silicon layer, a first arc-shaped silicon layer, a second island-shaped silicon layer, a second arc-shaped silicon layer, a third island-shaped silicon layer and a fourth island-shaped silicon layer, respectively. Further, each of the n+-type semiconductor layers may be a p+-type silicon layer, and each of the p+-type semiconductor layers may be a p+-type silicon layer. 
         [0019]    Preferably, in the above semiconductor device, the first island-shaped silicon layer, the first arc-shaped silicon layer, the second island-shaped silicon layer, the second arc-shaped silicon layer, the third island-shaped silicon layer and the fourth island-shaped silicon layer are a first n-type or non-doped island-shaped silicon layer, a first p-type or non-doped arc-shaped silicon layer, a second n-type or non-doped island-shaped silicon layer, a second p-type or non-doped arc-shaped silicon layer, a third p-type or non-doped island-shaped silicon layer and a fourth p-type or non-doped island-shaped silicon layer, respectively. 
         [0020]    As above, the semiconductor device according to the first aspect of the present invention comprises: a first inverter arranged at an intersection of the 1st row and the 1st column, wherein the first inverter includes a first island-shaped semiconductor layer, a first gate dielectric film in contact with at least a part of a periphery of the first island-shaped semiconductor layer, a first gate electrode having one surface in contact with the first gate dielectric film, a second gate dielectric film in contact with another surface of the first gate electrode, a first arc-shaped semiconductor layer in contact with at least a part of the second gate dielectric film, a first first-conductive-type high-concentration semiconductor layer arranged on a top of the first island-shaped semiconductor layer, a second first-conductive-type high-concentration semiconductor layer arranged underneath the first island-shaped semiconductor layer, a first second-conductive-type high-concentration semiconductor layer arranged on a top of the first arc-shaped semiconductor layer, and a second second-conductive-type high-concentration semiconductor layer arranged underneath the first arc-shaped semiconductor layer; a second inverter arranged at an intersection of the 2nd row and the 2nd column, wherein the second inverter includes a second island-shaped semiconductor layer, a third gate dielectric film in contact with at least a part of a periphery of the second island-shaped semiconductor layer, a second gate electrode having one surface in contact with the third gate dielectric film, a fourth gate dielectric film in contact with another surface of the second gate electrode, a second arc-shaped semiconductor layer in contact with at least a part of the fourth gate dielectric film, a third first-conductive-type high-concentration semiconductor layer arranged on a top of the second island-shaped semiconductor layer, a fourth first-conductive-type high-concentration semiconductor layer arranged underneath the second island-shaped semiconductor layer, a third second-conductive-type high-concentration semiconductor layer arranged on a top of the second arc-shaped semiconductor layer, and a fourth second-conductive-type high-concentration semiconductor layer arranged underneath the second arc-shaped semiconductor layer; a first selection transistor arranged at an intersection of the 1st row and the 2nd column, wherein the first selection transistor includes a third island-shaped semiconductor layer, a fifth gate dielectric film in contact with at least a part of a periphery of the third island-shaped semiconductor layer, a third gate electrode partially in contact with the fifth gate dielectric film, a fifth second-conductive-type high-concentration semiconductor layer arranged on a top of the third island-shaped semiconductor layer, and a sixth second-conductive-type high-concentration semiconductor layer arranged underneath the third island-shaped semiconductor layer; and a second selection transistor arranged at an intersection of the 2nd row and the 1st column, wherein the second selection transistor includes a fourth island-shaped semiconductor layer, a sixth gate dielectric film in contact with at least a part of a periphery of the fourth island-shaped semiconductor layer, a fourth gate electrode partially in contact with the sixth gate dielectric film, a seventh second-conductive-type high-concentration semiconductor layer arranged on a top of the fourth island-shaped semiconductor layer, and an eighth second-conductive-type high-concentration semiconductor layer arranged underneath the fourth island-shaped semiconductor layer. This makes it possible to provide a semiconductor device comprising a highly-integrated SGT-based SRAM. 
         [0021]    The semiconductor device according to the second aspect of the present invention comprises: a first inverter arranged at an intersection of the 1st row and the 1st column, wherein the first inverter includes a first island-shaped semiconductor layer, a first gate dielectric film surrounding a periphery of the first island-shaped semiconductor layer, a first gate electrode surrounding a periphery of the first gate dielectric film, a second gate dielectric film surrounding a part of a periphery of the first gate electrode, a first arc-shaped semiconductor layer in contact with a part of a periphery of the second gate dielectric film, a first first-conductive-type high-concentration semiconductor layer arranged on a top of the first island-shaped semiconductor layer, a second first-conductive-type high-concentration semiconductor layer arranged underneath the first island-shaped semiconductor layer, a first second-conductive-type high-concentration semiconductor layer arranged on a top of the first arc-shaped semiconductor layer, and a second second-conductive-type high-concentration semiconductor layer arranged underneath the first arc-shaped semiconductor layer; a second inverter arranged at an intersection of the 2nd row and the 2nd column, wherein the second inverter includes a second island-shaped semiconductor layer, a third gate dielectric film surrounding a periphery of the second island-shaped semiconductor layer, a second gate electrode surrounding a periphery of the third gate dielectric film, a fourth gate dielectric film surrounding a part of a periphery of the second gate electrode, a second arc-shaped semiconductor layer in contact with a part of a periphery of the fourth gate dielectric film, a third first-conductive-type high-concentration semiconductor layer arranged on a top of the second island-shaped semiconductor layer, a fourth first-conductive-type high-concentration semiconductor layer arranged underneath the second island-shaped semiconductor layer, a third second-conductive-type high-concentration semiconductor layer arranged on a top of the second arc-shaped semiconductor layer, and a fourth second-conductive-type high-concentration semiconductor layer arranged underneath the second arc-shaped semiconductor layer; a first selection transistor arranged at an intersection of the 1st row and the 2nd column, wherein the first selection transistor includes a third island-shaped semiconductor layer, a fifth gate dielectric film surrounding a periphery of the third island-shaped semiconductor layer, a third gate electrode surrounding a periphery of the fifth gate dielectric film, a fifth second-conductive-type high-concentration semiconductor layer arranged on a top of the third island-shaped semiconductor layer, and a sixth second-conductive-type high-concentration semiconductor layer arranged underneath the third island-shaped semiconductor layer; and a second selection transistor arranged at an intersection of the 2nd row and the 1st column, wherein the second selection transistor includes a fourth island-shaped semiconductor layer, a sixth gate dielectric film surrounding a periphery of the fourth island-shaped semiconductor layer, a fourth gate electrode surrounding a periphery of the sixth gate dielectric film, a seventh second-conductive-type high-concentration semiconductor layer arranged on a top of the fourth island-shaped semiconductor layer, and an eighth second-conductive-type high-concentration semiconductor layer arranged underneath the fourth island-shaped semiconductor layer. This makes it possible to provide a semiconductor device comprising a highly-integrated SGT-based SRAM. 
         [0022]    The semiconductor device according to the third aspect of the present invention comprises: a first inverter arranged at an intersection of the 1st row and the 1st column, wherein the first inverter includes a first island-shaped semiconductor layer, a first gate dielectric film surrounding a periphery of the first island-shaped semiconductor layer, a first gate electrode surrounding a periphery of the first gate dielectric film, a second gate dielectric film surrounding a part of a periphery of the first gate electrode, a first arc-shaped semiconductor layer in contact with a part of a periphery of the second gate dielectric film, a first first-conductive-type high-concentration semiconductor layer arranged on a top of the first island-shaped semiconductor layer, a second first-conductive-type high-concentration semiconductor layer arranged underneath the first island-shaped semiconductor layer, a first second-conductive-type high-concentration semiconductor layer arranged on a top of the first arc-shaped semiconductor layer, and a second second-conductive-type high-concentration semiconductor layer arranged underneath the first arc-shaped semiconductor layer; a second inverter arranged at an intersection of the 2nd row and the 2nd column, wherein the second inverter includes a second island-shaped semiconductor layer, a third gate dielectric film surrounding a periphery of the second island-shaped semiconductor layer, a second gate electrode surrounding a periphery of the third gate dielectric film, a fourth gate dielectric film surrounding a part of a periphery of the second gate electrode, a second arc-shaped semiconductor layer in contact with a part of a periphery of the fourth gate dielectric film, a third first-conductive-type high-concentration semiconductor layer arranged on a top of the second island-shaped semiconductor layer, a fourth first-conductive-type high-concentration semiconductor layer arranged underneath the second island-shaped semiconductor layer, a third second-conductive-type high-concentration semiconductor layer arranged on a top of the second arc-shaped semiconductor layer, and a fourth second-conductive-type high-concentration semiconductor layer arranged underneath the second arc-shaped semiconductor layer; a first selection transistor arranged at an intersection of the 1st row and the 2nd column, wherein the first selection transistor includes a third island-shaped semiconductor layer, a fifth gate dielectric film surrounding a periphery of the third island-shaped semiconductor layer, a third gate electrode surrounding a periphery of the fifth gate dielectric film, a fifth second-conductive-type high-concentration semiconductor layer arranged on a top of the third island-shaped semiconductor layer, and a sixth second-conductive-type high-concentration semiconductor layer arranged underneath the third island-shaped semiconductor layer; a second selection transistor arranged at an intersection of the 2nd row and the 1st column, wherein the second selection transistor includes a fourth island-shaped semiconductor layer, a sixth gate dielectric film surrounding a periphery of the fourth island-shaped semiconductor layer, a fourth gate electrode surrounding a periphery of the sixth gate dielectric film, a seventh second-conductive-type high-concentration semiconductor layer arranged on a top of the fourth island-shaped semiconductor layer, and an eighth second-conductive-type high-concentration semiconductor layer arranged underneath the fourth island-shaped semiconductor layer; a fifth first-conductive-type high-concentration semiconductor layer arranged underneath the second first-conductive-type high-concentration semiconductor layer, the second second-conductive-type high-concentration semiconductor layer and the eighth second-conductive-type high-concentration semiconductor layer; a sixth first-conductive-type high-concentration semiconductor layer arranged underneath the fourth first-conductive-type high-concentration semiconductor layer, the fourth second-conductive-type high-concentration semiconductor layer and the sixth second-conductive-type high-concentration semiconductor layer; a first semiconductor-metal compound layer formed on a part of respective sidewalls of the second second-conductive-type high-concentration semiconductor layer and the fifth first-conductive-type high-concentration semiconductor layer; a second semiconductor-metal compound layer formed on the eighth second-conductive-type high-concentration semiconductor layer and the fifth first-conductive-type high-concentration semiconductor layer; a third semiconductor-metal compound layer formed on a part of respective sidewalls of the fourth second-conductive-type high-concentration semiconductor layer and the sixth first-conductive-type high-concentration semiconductor layer; a fourth semiconductor-metal compound layer formed on the sixth second-conductive-type high-concentration semiconductor layer and the sixth first-conductive-type high-concentration semiconductor layer; a fifth semiconductor-metal compound layer formed on the first first-conductive-type high-concentration semiconductor layer; a sixth semiconductor-metal compound layer formed on the first second-conductive-type high-concentration semiconductor layer; a seventh semiconductor-metal compound layer formed on the third first-conductive-type high-concentration semiconductor layer; an eighth semiconductor-metal compound layer formed on the third second-conductive-type high-concentration semiconductor layer; a ninth semiconductor-metal compound layer formed on the fifth second-conductive-type high-concentration semiconductor layer; a tenth semiconductor-metal compound layer formed on the seventh second-conductive-type high-concentration semiconductor layer; a first contact connecting the first gate electrode and the fourth semiconductor-metal compound layer; and a second contact connecting the second gate electrode and the second semiconductor-metal compound layer. This makes it possible to provide a semiconductor device comprising a highly-integrated SGT-based SRAM. 
         [0023]    The semiconductor device according to the fourth aspect of the present invention comprises: a first inverter arranged at an intersection of the 1st row and the 1st column, wherein the first inverter includes a first island-shaped semiconductor layer, a first gate dielectric film surrounding a periphery of the first island-shaped semiconductor layer, a first gate electrode surrounding a periphery of the first gate dielectric film, a second gate dielectric film surrounding a part of a periphery of the first gate electrode, a first arc-shaped semiconductor layer in contact with a part of a periphery of the second gate dielectric film, a first p+-type semiconductor layer arranged on a top of the first island-shaped semiconductor layer, a second p+-type semiconductor layer arranged underneath the first island-shaped semiconductor layer, a first n+-type semiconductor layer arranged on a top of the first arc-shaped semiconductor layer and a second n+-type semiconductor layer arranged underneath the first arc-shaped semiconductor layer; a second inverter arranged at an intersection of the 2nd row and the 2nd column, wherein the second inverter includes a second island-shaped semiconductor layer, a third gate dielectric film surrounding a periphery of the second island-shaped semiconductor layer, a second gate electrode surrounding a periphery of the third gate dielectric film, a fourth gate dielectric film surrounding a part of a periphery of the second gate electrode, a second arc-shaped semiconductor layer in contact with a part of a periphery of the fourth gate dielectric film, a third p+-type semiconductor layer arranged on a top of the second island-shaped semiconductor layer, a fourth p+-type semiconductor layer arranged underneath the second island-shaped semiconductor layer, a third n+-type semiconductor layer arranged on a top of the second arc-shaped semiconductor layer, and a fourth n+-type semiconductor layer arranged underneath the second arc-shaped semiconductor layer; a first selection transistor arranged at an intersection of the 1st row and the 2nd column, wherein the first selection transistor includes a third island-shaped semiconductor layer, a fifth gate dielectric film surrounding a periphery of the third island-shaped semiconductor layer, a third gate electrode surrounding a periphery of the fifth gate dielectric film, a fifth n+-type semiconductor layer arranged on a top of the third island-shaped semiconductor layer, and a sixth n+-type semiconductor layer arranged underneath the third island-shaped semiconductor layer; and a second selection transistor arranged at an intersection of the 2nd row and the 1st column, wherein the second selection transistor includes a fourth island-shaped semiconductor layer, a sixth gate dielectric film surrounding a periphery of the fourth island-shaped semiconductor layer, a fourth gate electrode surrounding a periphery of the sixth gate dielectric film, a seventh n+-type semiconductor layer arranged on a top of the fourth island-shaped semiconductor layer, and an eighth n+-type semiconductor layer arranged underneath the fourth island-shaped semiconductor layer. This makes it possible to provide a semiconductor device comprising a highly-integrated SGT-based SRAM. 
         [0024]    The semiconductor device according to the fifth aspect of the present invention comprises: a first inverter arranged at an intersection of the 1st row and the 1st column, wherein the first inverter includes a first island-shaped semiconductor layer, a first gate dielectric film surrounding a periphery of the first island-shaped semiconductor layer, a first gate electrode surrounding a periphery of the first gate dielectric film, a second gate dielectric film surrounding a part of a periphery of the first gate electrode, a first arc-shaped semiconductor layer in contact with a part of a periphery of the second gate dielectric film, a first p+-type semiconductor layer arranged on a top of the first island-shaped semiconductor layer, a second p+-type semiconductor layer arranged underneath the first island-shaped semiconductor layer, a first n+-type semiconductor layer arranged on a top of the first arc-shaped semiconductor layer and a second n+-type semiconductor layer arranged underneath the first arc-shaped semiconductor layer; a second inverter arranged at an intersection of the 2nd row and the 2nd column, wherein the second inverter includes a second island-shaped semiconductor layer, a third gate dielectric film surrounding a periphery of the second island-shaped semiconductor layer, a second gate electrode surrounding a periphery of the third gate dielectric film, a fourth gate dielectric film surrounding a part of a periphery of the second gate electrode, a second arc-shaped semiconductor layer in contact with a part of a periphery of the fourth gate dielectric film, a third p+-type semiconductor layer arranged on a top of the second island-shaped semiconductor layer, a fourth p+-type semiconductor layer arranged underneath the second island-shaped semiconductor layer, a third n+-type semiconductor layer arranged on a top of the second arc-shaped semiconductor layer, and a fourth n+-type semiconductor layer arranged underneath the second arc-shaped semiconductor layer; a first selection transistor arranged at an intersection of the 1st row and the 2nd column, wherein the first selection transistor includes a third island-shaped semiconductor layer, a fifth gate dielectric film surrounding a periphery of the third island-shaped semiconductor layer, a third gate electrode surrounding a periphery of the fifth gate dielectric film, a fifth n+-type semiconductor layer arranged on a top of the third island-shaped semiconductor layer, and a sixth n+-type semiconductor layer arranged underneath the third island-shaped semiconductor layer; a second selection transistor arranged at an intersection of the 2nd row and the 1st column, wherein the second selection transistor includes a fourth island-shaped semiconductor layer, a sixth gate dielectric film surrounding a periphery of the fourth island-shaped semiconductor layer, a fourth gate electrode surrounding a periphery of the sixth gate dielectric film, a seventh n+-type semiconductor layer arranged on a top of the fourth island-shaped semiconductor layer, and an eighth n+-type semiconductor layer arranged underneath the fourth island-shaped semiconductor layer; a fifth p+-type semiconductor layer arranged underneath the second p+-type semiconductor layer, the second n+-type semiconductor layer and the eighth n+-type semiconductor layer; a sixth p+-type semiconductor layer arranged underneath the fourth p+-type semiconductor layer, the fourth n+-type semiconductor layer and the sixth n+-type semiconductor layer; a first semiconductor-metal compound layer formed on a part of respective sidewalls of the second n+-type semiconductor layer and the fifth p+-type semiconductor layer; a second semiconductor-metal compound layer formed on the eighth n+-type semiconductor layer and the fifth p+-type semiconductor layer; a third semiconductor-metal compound layer formed on a part of respective sidewalls of the fourth n+-type semiconductor layer and the sixth p+-type semiconductor layer; a fourth semiconductor-metal compound layer formed on the sixth n+-type semiconductor layer and the sixth p+-type semiconductor layer; a fifth semiconductor-metal compound layer formed on the first p+-type semiconductor layer; a sixth semiconductor-metal compound layer formed on the first n+-type semiconductor layer; a seventh semiconductor-metal compound layer formed on the third p+-type semiconductor layer; an eighth semiconductor-metal compound layer formed on the third n+-type semiconductor layer; a ninth semiconductor-metal compound layer formed on the fifth n+-type semiconductor layer; a tenth semiconductor-metal compound layer formed on the seventh n+-type semiconductor layer; a first contact connecting the first gate electrode and the fourth semiconductor-metal compound layer; and a second contact connecting the second gate electrode and the second semiconductor-metal compound layer. This makes it possible to provide a semiconductor device comprising a highly-integrated SGT-based SRAM. 
         [0025]    In a preferred embodiment of the present invention, the semiconductor device is configured to satisfy the following condition: Wp 1 ≈2 Wn 1 , wherein Wp 1  is an outer peripheral length of the first island-shaped semiconductor layer, and Wn 1  is a length of an arc of the first arc-shaped semiconductor layer in contact with a part of the periphery of the second gate dielectric film. In this case, a gate length of a pMOS transistor can be set to be twice as large as that of an nMOS transistor. This makes it possible to provide a semiconductor device comprising a highly-integrated SGT-based SRAM. 
         [0026]    In a preferred embodiment of the present invention, the semiconductor device is configured to satisfy the following condition: Wp 2 ≈2 Wn 2 , wherein Wp 2  is an outer peripheral length of the second island-shaped semiconductor layer, and Wn 2  is a length of an arc of the second arc-shaped semiconductor layer in contact with a part of the periphery of the fourth gate dielectric film. In this case, a gate length of a pMOS transistor can be set to be twice as large as that of an nMOS transistor. This makes it possible to provide a semiconductor device comprising a highly-integrated SGT-based SRAM. 
         [0027]    In a preferred embodiment of the present invention, the semiconductor device is configured to satisfy the following condition: Ln 1 ≈Lp 1 , wherein Ln 1  is a channel length of the first arc-shaped semiconductor layer, and Lp 1  is a channel length of the first island-shaped semiconductor layer. This makes it possible to provide a semiconductor device comprising a highly-integrated SGT-based SRAM 
         [0028]    In a preferred embodiment of the present invention, the semiconductor device is configured to satisfy the following condition: Ln 2 ≈Lp 2 , wherein Ln 2  is a channel length of the second arc-shaped semiconductor layer, and Lp 2  is a channel length of the second island-shaped semiconductor layer. This makes it possible to provide a semiconductor device comprising a highly-integrated SGT-based SRAM. 
         [0029]    In a preferred embodiment of the present invention, a first pMOS transistor, a first nMOS transistor, a second pMOS transistor and a second nMOS transistor are made up of a combination of the first island-shaped semiconductor layer, the first gate dielectric film surrounding the periphery of the first island-shaped semiconductor layer, the first gate electrode surrounding the periphery of the first gate dielectric film, the first p+-type semiconductor layer arranged on the top of the first island-shaped semiconductor layer, and the second p+-type semiconductor layer arranged underneath the first island-shaped semiconductor layer, a combination of the first gate electrode, the second gate dielectric film surrounding a part of the periphery of the first gate electrode, the first arc-shaped semiconductor layer in contact with a part of a periphery of the second gate dielectric film, a first n+-type semiconductor layer arranged on the top of the first arc-shaped semiconductor layer, and the second n+-type semiconductor layer arranged underneath the first arc-shaped semiconductor layer, a combination of the second island-shaped semiconductor layer, the third gate dielectric film surrounding the periphery of the second island-shaped semiconductor layer, the second gate electrode surrounding the periphery of the third gate dielectric film, the third p+-type semiconductor layer arranged on the top of the second island-shaped semiconductor layer, and the fourth p+-type semiconductor layer arranged underneath the second island-shaped semiconductor layer, and a combination of the second gate electrode, the fourth gate dielectric film surrounding a part of the periphery of the second gate electrode, the second arc-shaped semiconductor layer in contact with a part of the periphery of the fourth gate dielectric film, the third n+-type semiconductor layer arranged on the top of the second arc-shaped semiconductor layer, and the fourth n+-type semiconductor layer arranged underneath the second arc-shaped semiconductor layer, respectively, wherein: the first gate dielectric film is adapted to allow the first pMOS transistor to operate as an enhancement type; the second gate dielectric film is adapted to allow the first nMOS transistor to operate as an enhancement type; the first electrode is made of a material allowing the first pMOS transistor and the first nMOS transistor to operate as an enhancement type; the third gate dielectric film is adapted to allow the second nMOS transistor to operate as an enhancement type, and the first electrode is made of a material allowing the second pMOS transistor and the second nMOS transistor to operate as an enhancement type. In this case, each of the pMOS and nMOS transistors can be formed as an enhancement type. 
         [0030]    In a preferred embodiment of the present invention, each of the first to tenth semiconductor-metal compound layers is a silicon-metal compound layer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]      FIG. 1  shows a semiconductor device according to one embodiment of the present invention, wherein (a), (b) and (c) are a schematic diagram of the semiconductor device in a plane view, a sectional view taken along the line X-X′ in (a) and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0032]      FIG. 2  shows a step in one example of a production process for the semiconductor device according to the embodiment, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0033]      FIG. 3  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0034]      FIG. 4  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0035]      FIG. 5  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0036]      FIG. 6  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0037]      FIG. 7  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0038]      FIG. 8  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0039]      FIG. 9  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0040]      FIG. 10  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0041]      FIG. 11  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0042]      FIG. 12  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0043]      FIG. 13  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0044]      FIG. 14  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0045]      FIG. 15  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0046]      FIG. 16  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0047]      FIG. 17  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0048]      FIG. 18  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0049]      FIG. 19  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0050]      FIG. 20  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0051]      FIG. 21  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0052]      FIG. 22  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0053]      FIG. 23  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0054]      FIG. 24  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0055]      FIG. 25  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0056]      FIG. 26  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0057]      FIG. 27  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0058]      FIG. 28  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0059]      FIG. 29  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0060]      FIG. 30  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0061]      FIG. 31  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0062]      FIG. 32  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0063]      FIG. 33  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0064]      FIG. 34  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0065]      FIG. 35  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0066]      FIG. 36  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0067]      FIG. 37  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0068]      FIG. 38  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0069]      FIG. 39  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0070]      FIG. 40  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0071]      FIG. 41  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0072]      FIG. 42  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0073]      FIG. 43  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0074]      FIG. 44  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0075]      FIG. 45  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0076]      FIG. 46  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0077]      FIG. 47  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0078]      FIG. 48  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0079]      FIG. 49  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0080]      FIG. 50  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0081]      FIG. 51  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0082]      FIG. 52  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0083]      FIG. 53  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0084]      FIG. 54  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0085]      FIG. 55  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0086]      FIG. 56  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0087]      FIG. 57  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0088]      FIG. 58  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0089]      FIG. 59  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0090]      FIG. 60  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0091]      FIG. 61  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0092]      FIG. 62  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0093]      FIG. 63  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0094]      FIG. 64  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0095]      FIG. 65  shows a step in the example of the production process, wherein (a), (b) and (c) are a top plan view, a sectional view taken along the line X-X′ in (a), and a sectional view taken along the line Y-Y′ in (a), respectively. 
           [0096]      FIG. 66  is a diagram showing a semiconductor device structure formed by arranging the semiconductor device according to the embodiment in a three-row by three-column array. 
           [0097]      FIG. 67  is a diagram showing an inverter output terminal layer in the semiconductor device structure formed by arranging the semiconductor device according to the embodiment in a three-row by three-column array. 
           [0098]      FIG. 68  is a diagram showing a transistor layer in the semiconductor device structure formed by arranging the semiconductor device according to the embodiment in a three-row by three-column array. 
           [0099]      FIG. 69  is a diagram showing a contact layer and a first level metal layer in the semiconductor device structure formed by arranging the semiconductor device according to the embodiment in a three-row by three-column array. 
           [0100]      FIG. 70  is a diagram showing a second level metal layer, and a first level via (a contact between the first level metal layer and the second level metal layer), in the semiconductor device structure formed by arranging the semiconductor device according to the embodiment in a three-row by three-column array. 
           [0101]      FIG. 71  is a diagram showing a third level metal layer, and a second level via (a contact between the second level metal layer and the third level metal layer), in the semiconductor device structure formed by arranging the semiconductor device according to the embodiment in a three-row by three-column array. 
           [0102]      FIG. 72  is a diagram showing a fourth level metal layer, and a third level via (a contact between the third level metal layer and the fourth level metal layer), in the semiconductor device structure formed by arranging the semiconductor device according to the embodiment in a three-row by three-column array. 
       
    
    
     DETAILED DESCRIPTION 
       [0103]      FIG. 1  shows a semiconductor device according to one embodiment of the present invention, wherein (a), (b) and (c) are a schematic diagram of the semiconductor device in a plane view, a sectional view taken along the line X-X′ in (a) and a sectional view taken along the line Y-Y′ in (a), respectively. (a) is a top plan view in which some part is hatched for distinguishing regions. Some components are hatched in a plane view for distinguishing regions. Only two sectional views of the semiconductor device are shown for the easy of viewing. 
         [0104]    The semiconductor device according to this embodiment comprises: a first inverter  237  arranged at an intersection of the 1st row and the 1st column, wherein the first inverter  237  includes a first island-shaped silicon layer  137 , a first gate dielectric film  187  surrounding a periphery of the first island-shaped silicon layer  137 , a first gate electrode  178  surrounding a periphery of the first gate dielectric film  187 , a second gate dielectric film  187  surrounding a part of a periphery of the first gate electrode  178 , a first arc-shaped silicon layer  141  in contact with a part of a periphery of the second gate dielectric film, a first p+-type silicon layer  161  arranged on a top of the first island-shaped silicon layer  137 , a second p+-type silicon layer  162  arranged underneath the first island-shaped silicon layer  137 , a first n+-type silicon layer  154  arranged on a top of the first arc-shaped silicon layer  141 , and a second n+-type silicon layer  156  arranged underneath the first arc-shaped silicon layer  141 ; a second inverter  240  arranged at an intersection of the 2nd row and the 2nd column, wherein the second inverter  240  includes a second island-shaped silicon layer, a third gate dielectric film surrounding a periphery of the second island-shaped silicon layer, a second gate electrode  181  surrounding a periphery of the third gate dielectric film, a fourth gate dielectric film surrounding a part of a periphery of the second gate electrode  181 , a second arc-shaped silicon layer in contact with a part of a periphery of the fourth gate dielectric film, a third p+-type silicon layer arranged on a top of the second island-shaped silicon layer, a fourth p+-type silicon layer arranged underneath the second island-shaped silicon layer, a third n+-type silicon layer arranged on a top of the second arc-shaped silicon layer, and a fourth n+-type silicon layer arranged underneath the second arc-shaped silicon layer; a first selection transistor  239  arranged at an intersection of the 1st row and the 2nd column, wherein the first selection transistor  239  includes a third island-shaped silicon layer  138 , a fifth gate dielectric film  188  surrounding a periphery of the third island-shaped silicon layer  138 , a third gate electrode  179  surrounding a periphery of the fifth gate dielectric film  188 , a fifth n+-type silicon layer  155  arranged on a top of the third island-shaped silicon layer  138 , and a sixth n+-type silicon layer  157  arranged underneath the third island-shaped silicon layer  138 ; a second selection transistor  242  arranged at an intersection of the 2nd row and the 1st column, wherein the second selection transistor  242  includes a fourth island-shaped silicon layer  139 , a sixth gate dielectric film  189  surrounding a periphery of the fourth island-shaped silicon layer  139 , a fourth gate electrode  180  surrounding a periphery of the sixth gate dielectric film  189 , a seventh n+-type silicon layer  158  arranged on a top of the fourth island-shaped silicon layer  139 , and an eighth n+-type silicon layer  156  arranged underneath the fourth island-shaped silicon layer  139 ; a fifth p+-type silicon layer  143  arranged underneath the second p+-type silicon layer  162 , the second n+-type silicon layer  156  and the eighth n+-type silicon layer  156 ; a sixth p+-type silicon layer  144  arranged underneath the fourth p+-type silicon layer, the fourth n+-type silicon layer and the sixth n+-type silicon layer  157 ; a first silicon-metal compound layer  204  formed on a part of respective sidewalls of the second n+-type silicon layer  156  and the fifth p+-type silicon layer  143 ; a second silicon-metal compound layer  201  formed on the eighth n+-type silicon layer  156  and the fifth p+-type silicon layer  143 ; a third silicon-metal compound layer  205  formed on a part of respective sidewalls of the fourth n+-type silicon layer and the sixth p+-type silicon layer  144 ; a fourth silicon-metal compound layer  198  formed on the sixth n+-type silicon layer  157  and the sixth p+-type silicon layer  144 ; a fifth silicon-metal compound layer  197  formed on the first p+-type silicon layer  161 ; a sixth silicon-metal compound layer  196  formed on the first n+-type silicon layer  154 ; a seventh silicon-metal compound layer formed on the third p+-type silicon layer; an eighth silicon-metal compound layer formed on the third n+-type silicon layer; a ninth silicon-metal compound layer  199  formed on the fifth n+-type silicon layer  155 ; a tenth silicon-metal compound layer  200  formed on the seventh n+-type silicon layer  158 ; a first contact  209  connecting the first gate electrode  178  and the fourth silicon-metal compound layer  198 ; and a second contact  210  connecting the second gate electrode  181  and the second silicon-metal compound layer  201 . 
         [0105]    A contact  221  is formed on the fifth silicon-metal compound layer  197 . A contact  220  is formed on the sixth silicon-metal compound layer  196 . A contact  226  is formed on the seventh silicon-metal compound layer. A contact  227  is formed on the eighth silicon-metal compound layer. A contact  222  is formed on the ninth silicon-metal compound layer  199 . A contact  225  is formed on the tenth silicon-metal compound layer  200 . A contact  223  is formed on the third gate electrode  179 . A contact  224  is formed on the fourth gate electrode  180 . 
         [0106]    A first level metal  228  is formed on the contact  220 . A first level metal  229  is formed on the contact  221 . A first level metal  230  is formed on the contact  222 . A first level metal  231  is formed on the contact  223 . A first level metal  232  is formed on the contact  224 . A first level metal  233  is formed on the contact  225 . A first level metal  234  is formed on the contact  226 . A first level metal  235  is formed on the contact  227 . In the above manner, an SRAM memory cell is formed. 
         [0107]    The above semiconductor device is configured to satisfy the following condition: Wp 1 ≈2 Wn 1 , wherein Wp 1  is an outer peripheral length of the first island-shaped silicon layer  137 , and Wn 1  is a length of an arc of the first arc-shaped silicon layer  141  in contact with a part of the periphery of the second gate dielectric film  187 . Thus, a gate width of a pMOS transistor can be set to be twice as large as that of an nMOS transistor. In this case, it is preferable to satisfy the following condition: Ln 1 ≈Lp 1 , wherein Ln 1  is a channel length of the first arc-shaped silicon layer  141 , and Lp 1  is a channel length of the first island-shaped silicon layer  137 . 
         [0108]    The above semiconductor device is also configured to satisfy the following condition: Wp 2 ≈2 Wn 2 , wherein Wp 2  is an outer peripheral length of the second island-shaped silicon layer, and Wn 2  is a length of an arc of the second arc-shaped silicon layer in contact with a part of the periphery of the fourth gate dielectric film. Thus, a gate width of a pMOS transistor can be set to be twice as large as that of an nMOS transistor. In this case, it is preferable to satisfy the following condition: Ln 2 ≈Lp 2 , wherein Ln 2  is a channel length of the second arc-shaped silicon layer, and Lp 2  is a channel length of the second island-shaped silicon layer. 
         [0109]    With reference to  FIG. 2 , one example of a production process for forming a structure of the semiconductor device according to this embodiment will be described below. In these figures, the same elements or components are defined by a common reference numeral or code. Each of  FIG. 2  to  FIG. 65  shows a step in the example of the production process, wherein the figure suffixed with (a), the figure suffixed with (b) and the figure suffixed with (c) are a top plan view, a sectional view taken along the line X-X′ in the figure suffixed with (a), and a sectional view taken along the line Y-Y′ in the figure suffixed with (a), respectively. (a) are top plan views in which some part is hatched for distinguishing regions. 
         [0110]    Referring to  FIG. 2 , boron (B) is implanted into a p-type or non-doped silicon layer  103  formed on an oxide layer  101  to form a p+-type silicon layer  102  therein. 
         [0111]    Referring to  FIG. 3 , a resist  104  for forming an n-type silicon layer is formed. In cases where after-mentioned silicon layers  105 ,  106  are formed as a non-doped type, this step is unnecessary. 
         [0112]    Referring to  FIG. 4 , two n-type silicon layers  105 ,  106  are formed by implantation of phosphorus (P). In cases where these silicon layers  105 ,  106  are formed as a non-doped type, this step is unnecessary. 
         [0113]    Referring to  FIG. 5 , the resist  104  is stripped away, and then a heat treatment is performed. In cases where the silicon layers  105 ,  106  are formed as a non-doped type, this step is unnecessary. 
         [0114]    Referring to  FIG. 6 , an oxide film  107  is deposited, and then a nitride film  108  is deposited. 
         [0115]    Referring to  FIG. 7 , four resists  109 ,  110 ,  111 ,  112  for forming four (first, second, third, and fourth) island-shaped silicon layers is formed. 
         [0116]    Referring to  FIG. 8 , the nitride film  108  and the oxide film  107  are etched to form four nitride films  113 ,  114 ,  115  (one of the nitride films is indicated by the reference numeral  116  in  FIG. 9 , etc.) and four oxide films  117 ,  118 ,  119  (one of the oxide films is not indicated by a reference numeral). 
         [0117]    Referring to  FIG. 9 , the resists  109 ,  110 ,  111 ,  112  are stripped away. 
         [0118]    Referring to  FIG. 10 , an oxide film  121  is deposited. 
         [0119]    Referring to  FIG. 11 , the oxide film  121  is etched to form four oxide film-based sidewalls  122 ,  123 ,  124 ,  125 . 
         [0120]    Referring to  FIG. 12 , a nitride film  126  is deposited. 
         [0121]    Referring to  FIG. 13 , the nitride film  126  is etched to form four nitride film-based sidewalls  127 ,  128 ,  129 ,  130 . 
         [0122]    Referring to  FIG. 14 , four resists  131 ,  132 ,  133 ,  134  are formed. 
         [0123]    Referring to  FIG. 15 , the nitride film-based sidewalls  127 ,  128 ,  129 ,  130  are etched to form two nitride film-based hard masks  127  (one of the nitride film-based hard masks is indicated by the reference numeral  130  in  FIG. 17 , etc.) for forming first and second arc-shaped silicon layers. 
         [0124]    Referring to  FIG. 16 , the oxide film-based sidewalls  122 ,  123 ,  124 ,  125  are etched. 
         [0125]    Referring to  FIG. 17 , the resists  131 ,  132 ,  133 ,  134  are stripped away. 
         [0126]    Referring to  FIG. 18 , two resists  135 ,  136  for forming a diffusion-layer interconnection section is formed. 
         [0127]    Referring to  FIG. 19 , the silicon layer  103  is etched to form a diffusion-layer interconnection section thereon, 
         [0128]    Referring to  FIG. 20 , the resists  135 ,  136  are stripped away. 
         [0129]    Referring to  FIG. 21 , the oxide film-based sidewalls  122 ,  123 ,  124 ,  125  are etched away. 
         [0130]    Referring to  FIG. 22 , the silicon layer  103  and silicon layers  105 ,  106  are etched to form a first island-shaped silicon layer  137 , a third island-shaped silicon layer  138 , a fourth island-shaped silicon layer  139 , a second island-shaped silicon layer (indicated by the reference numeral  140  in  FIG. 23 , etc), a first arc-shaped silicon layer  141 , a second arc-shaped silicon layer (indicated by the reference numeral  142  in  FIG. 23 , etc), and fifth and sixth p+-type silicon layers  143 ,  144 . 
         [0131]    Referring to  FIG. 23 , the nitride films  113 ,  114 ,  115 ,  116  and the oxide films  117 ,  118 ,  119  are stripped away. 
         [0132]    Referring to  FIG. 24 , a nitride film  145  is deposited. 
         [0133]    Referring to  FIG. 25 , the nitride film  145  is etched to form six nitride film-based sidewalls  146 ,  147 ,  148 ,  149 ,  150 ,  151  for protecting channel regions during ion implantation in a subsequent step. 
         [0134]    Referring to  FIG. 26 , two resists  152 ,  153  for forming an n+-type silicon layer are formed. 
         [0135]    Referring to  FIG. 27 , arsenic (As) is implanted to form a first n+-type silicon layer  154 , a second n+-type silicon layer  156 , a third n+-type silicon layer  159 , a fourth n+-type silicon layer  157 , a fifth n+-type silicon layer  155 , a sixth n+-type silicon layer  157 , a seventh n+-type silicon layer  158  and an eighth n+-type silicon layer  156 . 
         [0136]    Referring to  FIG. 28 , the resists  152 ,  153  are stripped away. 
         [0137]    Referring to  FIG. 29 , a resist  160  for forming a p+-type silicon layer is formed. 
         [0138]    Referring to  FIG. 30 , boron (B) is implanted to form a first p+-type silicon layer  161 , a second p+-type silicon layer  162 , a third p+-type silicon layer  163  and a fourth p+-type silicon layer  164 . 
         [0139]    Referring to  FIG. 31 , the resist  160  is stripped away, and then a heat treatment is performed. 
         [0140]    Referring to  FIG. 32 , an oxide film  165  is deposited, and then subjected to flattening and etching-back to expose the first n+-type silicon layer  154 , the third n+-type silicon layer  159 , the fifth n+-type silicon layer  155 , the seventh n+-type silicon layer  158 , the first p+-type silicon layer  161  and the third p+-type silicon layer  163 . 
         [0141]    Referring to  FIG. 33 , a resist  166  for forming a gate section is formed. 
         [0142]    Referring to  FIG. 34 , a portion of the oxide film  165  corresponding to the gate section is etched. 
         [0143]    Referring to  FIG. 35 , the resist  166  is stripped away. 
         [0144]    Referring to  FIG. 36 , the nitride film-based sidewalls  148 ,  149 ,  150 ,  151  are etched away. 
         [0145]    Referring to  FIG. 37 , a high-K (high-dielectric constant) film  167  is deposited, and then a metal  168 , such as titanium nitride (TiN), is deposited. 
         [0146]    Referring to  FIG. 38 , a nitride film  169  is deposited. 
         [0147]    Referring to  FIG. 39 , four resists  170 ,  171 ,  172 ,  173  for forming a gate pad is formed. 
         [0148]    Referring to  FIG. 40 , the nitride film  169  is etched to form four nitride film-based hard masks  174 ,  175  (two of the nitride film-based hard masks are indicated by the reference numerals  176 ,  177  in  FIG. 41 , etc.) 
         [0149]    Referring to  FIG. 41 , the resists  170 ,  171 ,  172 ,  173  are stripped away. 
         [0150]    Referring to  FIG. 42 , the metal  168  is etched to form first to fourth gate electrodes  178 ,  181 ,  179 ,  180 . 
         [0151]    Referring to  FIG. 43 , a nitride film  182  is deposited. 
         [0152]    Referring to  FIG. 44 , the nitride film  182  is etched to form four nitride film-based sidewalls  183 ,  184 ,  185 ,  186 . 
         [0153]    Referring to  FIG. 45 , the high-K film is etched to form first to six high-K films (gate dielectric films)  187 ,  187 ,  190 ,  190 ,  188 ,  189 . 
         [0154]    Referring to  FIG. 46 , for resists  191 ,  192 ,  193 ,  194  for etching the oxide film  165  is formed. 
         [0155]    Referring to  FIG. 47 , the oxide film  165  is dry-etched. 
         [0156]    Referring to  FIG. 48 , the resists  191 ,  192 ,  193 ,  194  are stripped away. 
         [0157]    Referring to  FIG. 49 , the oxide film  165  is wet-etched. 
         [0158]    Referring to  FIG. 50 , a nitride film  195  is deposited. 
         [0159]    Referring to  FIG. 51 , the nitride film  195  is etched to form nitride film-based sidewalls  195 . 
         [0160]    Referring to  FIG. 52 , the oxide film  165  is dry-etched. 
         [0161]    Referring to  FIG. 53 , the oxide film  165  is wet-etched to expose the nitride film-based sidewalls  146 ,  147 . 
         [0162]    Referring to  FIG. 54 , the nitride film-based sidewalls  195  are etched, and a part of the nitride film-based sidewalls  146 ,  147  is etched, to expose a part of respective sidewalls of the second n+-type silicon layer  156 , the fifth p+-type silicon layer  143 , and a part of respective sidewalls of the fourth n+-type silicon layer  157  and the sixth p+-type silicon layer  144 . 
         [0163]    Referring to  FIG. 55 , a metal, such as nickel (Ni) or cobalt (Co), is deposited. Subsequently, a heat treatment is performed, and then an unreacted metal film is removed, to obtain a first silicon-metal compound layer  204  formed on a part of the sidewalls of the second n+-type silicon layer  156  and the fifth p+-type silicon layer  143 , a second silicon-metal compound layer  201  formed on the eighth n+silicon layer  156  and the fifth p+-type silicon layer  143 , a third silicon-metal compound layer  205  formed on a part of the sidewalls of the fourth n+-type silicon layer  157  and the sixth p+-type silicon layer  144 , a fourth silicon-metal compound layer  198  formed on the sixth n+-type silicon layer  157  and the sixth p+-type silicon layer  144 ; a fifth silicon-metal compound layer  197  formed on the first p+-type silicon layer  161 , a sixth silicon-metal compound layer  196  formed on the first n+-type silicon layer  154 , a seventh silicon-metal compound layer  202  formed on the third p+-type silicon layer  163 , an eighth silicon-metal compound layer  203  formed on the third n+-type silicon layer  159 , a ninth silicon-metal compound layer  199  formed on the fifth n+-type silicon layer  155 , and a tenth silicon-metal compound layer  200  formed on the seventh n+-type silicon layer  158 . 
         [0164]    Referring to  FIG. 56 , an interlayer film  206 , such as an oxide film, is formed. 
         [0165]    Referring to  FIG. 57 , a contact hole  207  is formed to expose a part of the first gate electrode  178  and the fourth silicon-metal compound layer  198 , and a contact hole  208  is formed to expose a part of the second gate electrode  181  and the second silicon-metal compound layer  201 . 
         [0166]    Referring to  FIG. 58 , a metal, such as tungsten (W), is deposited to form first and second contacts  209 ,  210 . 
         [0167]    Referring to  FIG. 59 , an interlayer film  211  is formed. 
         [0168]    Referring to  FIG. 60 , a contact hole  212  is formed on the third gate electrode  179 , and a contact hole  213  is formed on the fourth gate electrode  180 . 
         [0169]    Referring to  FIG. 61 , a contact hole  214  is formed on the sixth silicon-metal compound layer  196 , and a contact hole  215  is formed on the eighth silicon-metal compound layer  203 . 
         [0170]    Referring to  FIG. 62 , four contact holes  216 ,  217 ,  218 ,  219  are formed on the fifth silicon-metal compound layer  197 , the ninth silicon-metal compound layer  199 , the tenth silicon-metal compound layer  200  and the seventh silicon-metal compound layer  202 , respectively. 
         [0171]    Referring to  FIG. 63 , a metal, such as tungsten (W), is deposited to form eight contacts  220 ,  221 ,  222 ,  223 ,  224 ,  225 ,  226 ,  227 . 
         [0172]    Referring to  FIG. 64 , eight first level metals  228 ,  229 ,  230 ,  231 ,  232 ,  233 ,  234 ,  235  are formed on respective ones of the eight contacts. 
         [0173]    Referring to  FIG. 65 , an interlayer film  236  is formed. In the above manner, an SRAM memory cell is formed. 
         [0174]    With reference to  FIGS. 66 to 72 , one example of a semiconductor device structure formed by arranging the semiconductor device according to the above embodiment in a three-row by three-column array. In these figures, the same elements or components are defined by a common reference numeral or code.  FIG. 66  shows the semiconductor device structure formed by arranging the semiconductor device according to the above embodiment in a three-row by three-column array.  FIG. 67  shows an inverter output terminal layer in the semiconductor device structure, and  FIG. 68  shows a transistor layer in the semiconductor device structure.  FIG. 69  shows a contact layer and a first level metal layer in the semiconductor device structure, and  FIG. 70  shows a second level metal layer, and a first level via (a contact between the first level metal layer and the second level metal layer), in the semiconductor device structure.  FIG. 71  shows a third level metal layer, and a second level via (a contact between the second level metal layer and the third level metal layer), in the semiconductor device structure, and  FIG. 72  shows a fourth level metal layer, and a third level via (a contact between the third level metal layer and the fourth level metal layer), in the semiconductor device structure. 
         [0175]    An inverter  319  is arranged at an intersection of the 1st row and the 1st column. A selection transistor  337  is arranged at an intersection of the 1st row and the 2nd column. A selection transistor  340  is arranged at an intersection of the 2nd row and the 1st column. An inverter  322  is arranged at an intersection of the 2nd row and the 2nd column. The inverter  319  and the selection transistor  340  are connected to each other by an output terminal  301 . The inverter  322  and the selection transistor  337  are connected to each other by an output terminal  302 . An input terminal  355  of the inverter  319  is connected to the output terminal  302  via a contact  374 . An input terminal  358  of the inverter  322  is connected to the output terminal  301  via a contact  373 . 
         [0176]    An inverter  320  is arranged at an intersection of the 1st row and the 4th column. A selection transistor  338  is arranged at an intersection of the 1st row and the 3rd column. A selection transistor  341  is arranged at an intersection of the 2nd row and the 4th column. An inverter  323  is arranged at an intersection of the 2nd row and the 3rd column. The inverter  323  and the selection transistor  338  are connected to each other by an output terminal  303 . The inverter  320  and the selection transistor  341  are connected to each other by an output terminal  304 . An input terminal  359  of the inverter  323  is connected to the output terminal  304  via a contact  376 . An input terminal  356  of the inverter  320  is connected to the output terminal  303  via a contact  375 . 
         [0177]    An inverter  321  is arranged at an intersection of the 1st row and the 5th column. A selection transistor  339  is arranged at an intersection of the 1st row and the 6th column. A selection transistor  342  is arranged at an intersection of the 2nd row and the 5th column. An inverter  324  is arranged at an intersection of the 2nd row and the 6th column. The inverter  321  and the selection transistor  342  are connected to each other by an output terminal  305 . The inverter  324  and the selection transistor  339  are connected to each other by an output terminal  306 . An input terminal  357  of the inverter  321  is connected to the output terminal  306  via a contact  378 . An input terminal  360  of the inverter  324  is connected to the output terminal  305  via a contact  377 . 
         [0178]    The selection transistor  340  has a gate electrode  393 . The selection transistor  337  and the selection transistor  338  have a gate electrode  391 . The selection transistor  341  and the selection transistor  342  have a gate electrode  394 . The selection transistor  339  has a gate electrode  392 . 
         [0179]    An inverter  325  is arranged at an intersection of the 3rd row and the 2nd column. A selection transistor  343  is arranged at an intersection of the 3rd row and the 1st column. A selection transistor  346  is arranged at an intersection of the 4th row and the 2nd column. An inverter  328  is arranged at an intersection of the 4th row and the 1st column. The inverter  328  and the selection transistor  343  are connected to each other by an output terminal  307 . The inverter  325  and the selection transistor  346  are connected to each other by an output terminal  308 . An input terminal  364  of the inverter  328  is connected to the output terminal  308  via a contact  380 . An input terminal  361  of the inverter  325  is connected to the output terminal  307  via a contact  379 . 
         [0180]    An inverter  326  is arranged at an intersection of the 3rd row and the 3rd column. A selection transistor  344  is arranged at an intersection of the 3rd row and the 4th column. A selection transistor  347  is arranged at an intersection of the 4th row and the 3rd column. An inverter  329  is arranged at an intersection of the 4th row and the 4th column. The inverter  326  and the selection transistor  347  are connected to each other by an output terminal  309 . The inverter  329  and the selection transistor  344  are connected to each other by an output terminal  310 . An input terminal  362  of the inverter  326  is connected to the output terminal  310  via a contact  382 . An input terminal  365  of the inverter  329  is connected to the output terminal  309  via a contact  381 . 
         [0181]    An inverter  327  is arranged at an intersection of the 3rd row and the 6th column. A selection transistor  345  is arranged at an intersection of the 3rd row and the 5th column. A selection transistor  348  is arranged at an intersection of the 4th row and the 6th column. An inverter  330  is arranged at an intersection of the 4th row and the 5th column. The inverter  330  and the selection transistor  345  are connected to each other by an output terminal  311 . The inverter  327  and the selection transistor  348  are connected to each other by an output terminal  312 . An input terminal  366  of the inverter  330  is connected to the output terminal  312  via a contact  384 . An input terminal  363  of the inverter  327  is connected to the output terminal  311  via a contact  383 . 
         [0182]    The selection transistor  343  has a gate electrode  395 . The selection transistor  346  and the selection transistor  347  have a gate electrode  397 . The selection transistor  344  and the selection transistor  345  have a gate electrode  396 . The selection transistor  348  has a gate electrode  398 . 
         [0183]    An inverter  331  is arranged at an intersection of the 5th row and the 1st column. A selection transistor  349  is arranged at an intersection of the 5th row and the 2nd column. A selection transistor  352  is arranged at an intersection of the 6th row and the 1st column. An inverter  334  is arranged at an intersection of the 6th row and the 2nd column. The inverter  331  and the selection transistor  352  are connected to each other by an output terminal  313 . The inverter  334  and the selection transistor  349  are connected to each other by an output terminal  314 . An input terminal  367  of the inverter  331  is connected to the output terminal  314  via a contact  386 . An input terminal  370  of the inverter  334  is connected to the output terminal  313  via a contact  385 . 
         [0184]    An inverter  332  is arranged at an intersection of the 5th row and the 4th column. A selection transistor  350  is arranged at an intersection of the 5th row and the 3rd column. A selection transistor  353  is arranged at an intersection of the 6th row and the 4th column. An inverter  335  is arranged at an intersection of the 6th row and the 3rd column. The inverter  335  and the selection transistor  350  are connected to each other by an output terminal  315 . The inverter  332  and the selection transistor  353  are connected to each other by an output terminal  316 . An input terminal  371  of the inverter  335  is connected to the output terminal  316  via a contact  388 . An input terminal  368  of the inverter  332  is connected to the output terminal  315  via a contact  387 . 
         [0185]    An inverter  333  is arranged at an intersection of the 5th row and the 5th column. A selection transistor  351  is arranged at an intersection of the 5th row and the 6th column. A selection transistor  354  is arranged at an intersection of the 6th row and the 5th column. An inverter  336  is arranged at an intersection of the 6th row and the 6th column. The inverter  333  and the selection transistor  354  are connected to each other by an output terminal  317 . The inverter  336  and the selection transistor  351  are connected to each other by an output terminal  318 . An input terminal  369  of the inverter  333  is connected to the output terminal  318  via a contact  390 . An input terminal  372  of the inverter  336  is connected to the output terminal  317  via a contact  389 . 
         [0186]    The selection transistor  352  has a gate electrode  401 . The selection transistor  349  and the selection transistor  350  have a gate electrode  399 . The selection transistor  353  and the selection transistor  354  have a gate electrode  402 . The selection transistor  351  has a gate electrode  400 . 
         [0187]    A contact  403  is arranged on an nMOS transistor of the inverter  319 , and a contact  404  is arranged on a pMOS transistor of the inverter  319 . A contact  412  is arranged on the selection transistor  340 . A contact  414  is arranged on an nMOS transistor of the inverter  322 , and a contact  413  is arranged on a pMOS transistor of the inverter  322 . A contact  405  is arranged on the selection transistor  337 . The contact  414  is also arranged on an nMOS transistor of the inverter  323 , and a contact  415  is arranged on a pMOS transistor of the inverter  323 . A contact  407  is arranged on the selection transistor  338 . A contact  409  is arranged on an nMOS transistor of the inverter  320 , and a contact  408  is arranged on a pMOS transistor of the inverter  320 . A contact  416  is arranged on the selection transistor  341 . The contact  409  is also arranged on an nMOS transistor of the inverter  321 , and a contact  410  is arranged on a pMOS transistor of the inverter  321 . A contact  418  is arranged on the selection transistor  342 . A contact  420  is arranged on an nMOS transistor of the inverter  324 , and a contact  419  is arranged on a pMOS transistor of the inverter  324 . A contact  411  is arranged on the selection transistor  339 . A contact  406  is arranged on the gate electrode  391 , and a contact  417  is arranged on the gate electrode  394 . 
         [0188]    A contact  430  is arranged on an nMOS transistor of the inverter  328 , and a contact  431  is arranged on a pMOS transistor of the inverter  328 . A contact  421  is arranged on the selection transistor  343 . A contact  423  is arranged on an nMOS transistor of the inverter  325 , and a contact  422  is arranged on a pMOS transistor of the inverter  325 . A contact  432  is arranged on the selection transistor  346 . The contact  423  is also arranged on an nMOS transistor of the inverter  326 , and a contact  424  is arranged on a pMOS transistor of the inverter  326 . A contact  434  is arranged on the selection transistor  347 . A contact  436  is arranged on an nMOS transistor of the inverter  329 , and a contact  435  is arranged on a pMOS transistor of the inverter  329 . A contact  425  is arranged on the selection transistor  344 . The contact  436  is also arranged on an nMOS transistor of the inverter  330 , and a contact  437  is arranged on a pMOS transistor of the inverter  330 . A contact  427  is arranged on the selection transistor  345 . A contact  429  is arranged on an nMOS transistor of the inverter  327 , and a contact  428  is arranged on a pMOS transistor of the inverter  327 . A contact  438  is arranged on the selection transistor  348 . A contact  433  is arranged on the gate electrode  397 , and a contact  426  is arranged on the gate electrode  396 . 
         [0189]    A contact  439  is arranged on an nMOS transistor of the inverter  331 , and a contact  440  is arranged on a pMOS transistor of the inverter  331 . A contact  448  is arranged on the selection transistor  352 . A contact  450  is arranged on an nMOS transistor of the inverter  334 , and a contact  449  is arranged on a pMOS transistor of the inverter  334 . A contact  441  is arranged on the selection transistor  349 . The contact  450  is also arranged on an nMOS transistor of the inverter  335 , and a contact  451  is arranged on a pMOS transistor of the inverter  335 . A contact  443  is arranged on the selection transistor  350 . A contact  445  is arranged on an nMOS transistor of the inverter  332 , and a contact  444  is arranged on a pMOS transistor of the inverter  332 . A contact  452  is arranged on the selection transistor  353 . The contact  445  is also arranged on an nMOS transistor of the inverter  333 , and a contact  446  is arranged on a pMOS transistor of the inverter  333 . A contact  454  is arranged on the selection transistor  354 . A contact  456  is arranged on an nMOS transistor of the inverter  336 , and a contact  455  is arranged on a pMOS transistor of the inverter  336 . A contact  447  is arranged on the selection transistor  351 . A contact  442  is arranged on the gate electrode  399 , and a contact  453  is arranged on the gate electrode  402 . 
         [0190]    A first level metal  457  is connected to the contact  403 , and a first level metal  458  is connected to the contact  404 . A first level metal  459  is connected to the contact  405 , and a first level metal  460  is connected to the contact  406 . A first level metal  461  is connected to the contact  407 , and a first level metal  462  is connected to the contact  408 . A first level metal  463  is connected to the contact  409 , and a first level metal  464  is connected to the contact  410 . A first level metal  465  is connected to the contact  411 . 
         [0191]    A first level metal  466  is connected to the contacts  412 ,  421 , and a first level metal  467  is connected to the contacts  413 ,  422 . A first level metal  468  is connected to the contacts  414 ,  423 , and a first level metal  469  is connected to the contacts  415 ,  424 . A first level metal  470  is connected to the contacts  416 ,  425 . A first level metal  471  is connected to the contact  417 , and a first level metal  472  is connected to the contact  472 . A first level metal  473  is connected to the contacts  418 ,  427 . A first level metal  474  is connected to the contacts  419 ,  428 , and a first level metal  475  is connected to the contacts  420 ,  429 . 
         [0192]    A first level metal  476  is connected to the contacts  430 ,  439 , and a first level metal  477  is connected to the contacts  431 ,  440 . A first level metal  478  is connected to the contacts  432 ,  441 . A first level metal  479  is connected to the contact  433 , and a first level metal  480  is connected to the contact  442 . A first level metal  481  is connected to the contacts  434 ,  443 . A first level metal  482  is connected to the contacts  435 ,  444 , and a first level metal  483  is connected to the contacts  436 ,  445 . A first level metal  484  is connected to the contacts  437 ,  446 , and a first level metal  485  is connected to the contacts  438 ,  447 . 
         [0193]    A first level metal  486  is connected to the contact  448 , and a first level metal  487  is connected to the contact  449 . A first level metal  488  is connected to the contact  450 , and a first level metal  489  is connected to the contact  451 . A first level metal  490  is connected to the contact  452 , and a first level metal  491  is connected to the contact  453 . A first level metal  492  is connected to the contact  454 , and a first level metal  493  is connected to the contact  455 . A first level metal  494  is connected to the contact  456 . 
         [0194]    A first level via  495  is arranged on the first level metal  460 , and a first level via  496  is arranged on the first level metal  471 . A first level via  497  is arranged on the first level metal  466 , and a first level via  498  is arranged on the first level metal  467 . A first level via  499  is arranged on the first level metal  468 , and a first level via  500  is arranged on the first level metal  469 . A first level via  501  is arranged on the first level metal  470 , and a first level via  502  is arranged on the first level metal  473 . A first level via  503  is arranged on the first level metal  474 . A first level via  505  is arranged on the first level metal  479 , and a first level via  504  is arranged on the first level metal  472 . A first level via  506  is arranged on the first level metal  477 , and a first level via  507  is arranged on the first level metal  478 . A first level via  508  is arranged on the first level metal  481 , and a first level via  509  is arranged on the first level metal  482 . A first level via  510  is arranged on the first level metal  483 , and a first level via  511  is arranged on the first level metal  484 . A first level via  512  is arranged on the first level metal  485 . A first level via  513  is arranged on the first level metal  480 , and a first level via  514  is arranged on the first level metal  491 . 
         [0195]    A second level metal  515  is connected to the first level vias  495 ,  496 . A second level metal  516  is connected to the first level via  497 , and a second level metal  517  is connected to the first level via  498 . A second level metal  518  is connected to the first level via  499 , and a second level metal  519  is connected to the first level via  500 . A second level metal  520  is connected to the first level via  501 , and a second level metal  521  is connected to the first level via  502 . A second level metal  522  is connected to the first level via  503 . A second level metal  523  is connected to the first level vias  505 ,  504 . 
         [0196]    A second level metal  523  is connected to the first level via  506 , and a second level metal  525  is connected to the first level via  507 . A second level metal  526  is connected to the first level via  508 , and a second level metal  527  is connected to the first level via  509 . A second level metal  528  is connected to the first level via  510 , and a second level metal  529  is connected to the first level via  511 . A second level metal  530  is connected to the first level via  512 . A second level metal  531  is connected to the first level vias  513 ,  514 . 
         [0197]    A second level via  532  is arranged on the second level metal  516 , and a second level via  533  is arranged on the second level metal  517 . A second level via  534  is arranged on the second level metal  518 , and a second level via  535  is arranged on the second level metal  519 . A second level via  536  is arranged on the second level metal  520 , and a second level via  537  is arranged on the second level metal  521 . A second level via  538  is arranged on the second level metal  522 , and a second level via  539  is arranged on the second level metal  524 . A second level via  540  is arranged on the second level metal  525 , and a second level via  541  is arranged on the second level metal  526 . A second level via  542  is arranged on the second level metal  527 , and a second level via  543  is arranged on the second level metal  528 . A second level via  544  is arranged on the second level metal  529 , and a second level via  545  is arranged on the second level metal  530 . 
         [0198]    A third level metal  546  is connected to the second level via  534 , and a third level metal  549  is connected to the second level via  532 . A third level metal  550  is connected to the second level via  536 , and a third level metal  551  is connected to the second level via  537 . A third level metal  547  is connected to the second level vias  533 ,  535 ,  538 ,  539 ,  542 ,  544 . A third level metal  552  is connected to the second level via  540 , and a third level metal  553  is connected to the second level via  541 . A third level metal  554  is connected to the second level via  545 , and a third level metal  548  is connected to the second level via  543 . 
         [0199]    A third level via  561  is arranged on the third level metal  549 , and a third level via  564  is arranged on the third level metal  550 . A third level via  565  is arranged on the third level metal  551 , and a third level via  562  is arranged on the third level metal  552 . A third level via  563  is arranged on the third level metal  553 , and a third level via  566  is arranged on the third level metal  554 . 
         [0200]    A fourth level metal  555  is connected to the third level via  561 , and a fourth level metal  556  is connected to the third level via  562 . A fourth level metal  557  is connected to the third level via  563 , and a fourth level metal  558  is connected to the third level via  564 . A fourth level metal  559  is connected to the third level via  565 , and a fourth level metal  560  is connected to the third level via  566 . 
         [0201]    Having described and illustrated the principles of the present invention by reference to one preferred embodiment, it should be apparent that the preferred embodiment may be modified in arrangement and detail without departing from the principles disclosed herein and that it is intended that the application be construed as including all such modifications and variations insofar as they come within the spirit and scope of the subject matter disclosed herein. 
       EXPLANATIONS OF LETTERS OR NUMERALS 
       [0000]    
       
           101 : oxide film 
           102 : p+-type silicon layer 
           103 : p-type or non-doped silicon layer 
           104 : resist 
           105 : n-type or non-doped silicon layer 
           106 : n-type or non-doped silicon layer 
           107 : oxide film 
           108 : nitride film 
           109  to  112 : resist 
           113  to  116 : nitride film 
           117  to  119 : oxide film 
           121 : oxide film 
           122  to  125 : oxide film-based sidewall 
           126 : nitride film 
           127 : nitride film-based sidewall, nitride film-based hard mask 
           128 ,  129 : nitride film-based sidewall 
           130 : nitride film-based sidewall, nitride film-based hard mask 
           131  to  136 : resist 
           137 : first island-shaped silicon layer 
           138 : third island-shaped silicon layer 
           139 : fourth island-shaped silicon layer 
           140 : second island-shaped silicon layer 
           141 : first arc-shaped silicon layer 
           142 : second arc-shaped silicon layer 
           143 ,  144 : p+-type silicon layer 
           145 : nitride film 
           146  to  151 : nitride film-based sidewall 
           152  to  153 : resist 
           154  to  159 : n+-type silicon layer 
           160 : resist 
           161  to  164 : p+-type silicon layer 
           165 : oxide layer 
           166 : resist 
           167 : high-K film 
           168 : metal 
           169 : nitride film 
           170  to  173 : resist 
           174  to  177 : nitride film-based sidewall 
           178  to  181 : gate electrode 
           182 : nitride film 
           183  to  186 : nitride film-based sidewall 
           187  to  190 : gate dielectric film, high-K film 
           191  to  194 : resist 
           195 : nitride film-based sidewall 
           196  to  205 : silicon-metal compound layer 
           206 : interlayer film 
           207 ,  208 : contact hole 
           209 ,  210 : contact 
           211 : interlayer film 
           212  to  219 : contact hole 
           220  to  227 : contact 
           228  to  235 : first level metal 
           236 : interlayer film 
           237 : first inverter 
           239 : first selection transistor 
           240 : second inverter 
           242 : second selection transistor 
           301  to  318 : output terminal 
           319  to  336 : inverter 
           337  to  354 : selection transistor 
           355  to  372 : input terminal 
           373  to  390 : contact 
           391  to  402 : gate electrode 
           403  to  456 : contact 
           457  to  494 : first level metal 
           495  to  514 : first level via 
           515  to  531 : second level metal 
           532  to  545 : second level via 
           546  to  554 : third level metal 
           555  to  560 : fourth level via 
           561  to  566 : third level via