Patent Publication Number: US-2023155026-A1

Title: Semiconductor device and semiconductor apparatus including the semiconductor device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2021-0158042, filed on Nov. 16, 2021, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. 
     BACKGROUND 
     Some example embodiments relate to a semiconductor device and/or a semiconductor apparatus including the semiconductor device. 
     Ferroelectrics are materials with ferroelectricity that maintain spontaneous polarization by aligning internal electric dipole moments even when no external electric field is applied thereto. Research has been made to improve the performance of a semiconductor device by applying such a ferroelectric to the semiconductor device. 
     SUMMARY 
     Provided is a semiconductor device and/or a semiconductor apparatus including the semiconductor device. 
     Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, and/or may be learned by practice of the various example embodiments. 
     According to some example embodiments, a semiconductor device includes a substrate having a channel layer in or on the substrate and including a dopant, a ferroelectric layer on the channel layer, and a gate on the ferroelectric layer. The channel layer may have a doping concentration of greater than or equal to 1×10 15  cm −3  and less than or equal to 1×10 21  cm −3 . 
     The channel layer may be in an upper portion of the substrate integrally with the substrate, and a source and a drain may be at opposite sides of the channel layer. 
     The channel layer may be at least partially on the substrate separate from the substrate, and a source and a drain may be at opposite sides of the channel layer. 
     The channel layer may include at least one of Si, Ge, SiGe, a group III-V semiconductor, an oxide semiconductor, a nitride semiconductor, an oxynitride semiconductor, a two-dimensional (2D) semiconductor material, quantum dots, or an organic semiconductor. 
     A dopant included in the channel layer may include at least one of a group III element or a group V element. 
     The channel layer may have a doping concentration of greater than or equal to 1×10 15  cm −3  and less than or equal to 1×10 18  cm −3 . 
     The ferroelectric layer may include one or more of a fluorite-based material or a perovskite-based material. The ferroelectric layer may include at least one of a hafnium oxide, a zirconium oxide, or a hafnium-zirconium oxide. The ferroelectric layer may further include a dopant of at least one of Si, Al, La, Y, Sr, or Gd. 
     The semiconductor device may further include a paraelectric layer between the channel layer and the ferroelectric layer. The paraelectric layer may include at least one of a silicon oxide, a silicon nitride, an aluminum oxide, a silicon oxynitride, a lanthanum oxide, or an yttrium oxide. 
     The channel layer may have one or more of a sheet channel structure, a fin channel structure, or a gate-all-around channel structure. 
     The gate may include a metal, a metal nitride, polysilicon, or a 2D conductive material. 
     According to some example embodiments, a semiconductor apparatus includes a field effect transistor, and a capacitor electrically connected to the field effect transistor. The field effect transistor includes a substrate having a channel layer in or on the substrate and including a dopant, a ferroelectric layer on the channel layer, and a gate on the ferroelectric layer. The channel layer may have a doping concentration of greater than or equal to 1×10 15  cm −3  and less than or equal to 1×10 21  cm −3 . 
     The channel layer may be in an upper portion of the substrate integrally with the substrate, and a source and a drain may be provided at opposite sides of the channel layer. 
     The channel layer may be at least partially on the substrate separate from the substrate, and a source and a drain may be at opposite sides of the channel layer. 
     The channel layer may include at least one of Si, Ge, SiGe, a group III-V semiconductor, an oxide semiconductor, a nitride semiconductor, an oxynitride semiconductor, a 2D semiconductor material, quantum dots, or an organic semiconductor. 
     The channel layer may have a doping concentration of greater than or equal to 1×10 15  cm −3  and less than or equal to 1×10 18  cm −3 . 
     The ferroelectric layer may include one or more of a fluorite-based material or perovskite. The ferroelectric layer may include at least one of a hafnium oxide, a zirconium oxide, or a hafnium-zirconium oxide. The ferroelectric layer may further include a dopant of at least one of Si, Al, La, Y, Sr, or Gd. 
     The field effect transistor may further include a paraelectric layer between the channel layer and the ferroelectric layer. The paraelectric layer may include at least one of a silicon oxide, a silicon nitride, an aluminum oxide, a silicon oxynitride, a lanthanum oxide, or an yttrium oxide. 
     The gate may include a metal, a metal nitride, polysilicon, or a 2D conductive material. 
     According to some example embodiments, an electronic apparatus includes the above-described semiconductor apparatus. 
     According to various example embodiments, a semiconductor device may include a channel layer comprising dopants at a concentration of greater than or equal to 1×10 15  cm −3  and less than or equal to 1×10 21  cm −3 , and a ferroelectric layer on the channel layer. 
     The semiconductor device may further include a substrate, the channel layer integral in the substrate, and a source and a drain, the source and the drain integral with the substrate and at opposite ends of the channel layer. 
     The source and the drain may include first dopants of a first conductivity type opposite to a conductivity type of second dopants in the channel layer. 
     According to some example embodiments, a method of fabricating the semiconductor device may include provisioning the substrate, forming the channel layer by implanting the substrate with the second dopants at a first dose, forming the ferroelectric layer on the channel layer, and forming the source and the drain by implanting the substrate with the first dopants at a second dose. 
     The forming the source and drain regions may be performed after the forming the ferroelectric layer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and/or advantages of certain example embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    is a cross-sectional view of a semiconductor device according to various example embodiments; 
         FIG.  2    is a graph showing an effect of improving the subthreshold swing (SS) characteristics of the semiconductor device of  FIG.  1   ; 
         FIG.  3    is a graph showing the polarization P-voltage V characteristics of a capacitor having a metal-ferroelectric-metal (MFM) structure and a capacitor having a metal-ferroelectric-insulator-metal (MFIM) structure; 
         FIG.  4    is a graph showing a simulation result of the polarization P-voltage V characteristics when the doping concentration of a channel layer in the semiconductor device of  FIG.  1    is 1×10 20  cm −3  and 5×10 17  cm −3 ; 
         FIGS.  5 A to  5 C  are graphs showing experiment results of the polarization P-voltage V characteristics when the doping concentrations of a channel layer in the semiconductor device of  FIG.  1    are 1×10 13  cm −3 , 1×10 14  cm −3  , and 1×10 15  cm −3 , respectively; 
         FIG.  6    is a graph showing remnant polarization 2P r  and coercive voltage +V c  according to the doping concentration of a channel layer, which is calculated based on the results shown in  FIGS.  5 A to  5 C ; 
         FIG.  7    is a cross-sectional view of a semiconductor device according to another embodiment; 
         FIG.  8    is a perspective view of a semiconductor device according to another embodiment; 
         FIG.  9    is a cross-sectional view taken along line A-A′ of  FIG.  8   ; 
         FIG.  10    is a perspective view of a semiconductor device according to another embodiment. 
         FIG.  11    is a cross-sectional view taken along line B-B′ of  FIG.  10   ; 
         FIG.  12    is a cross-sectional view of a semiconductor apparatus according to various example embodiments; 
         FIGS.  13  and  14    are schematic conceptual views showing a device architecture that is applicable to an electronic apparatus according to various example embodiments; 
         FIG.  15    is a cross-sectional view of a semiconductor device, according to various example embodiments; and 
         FIG.  16    is a flow-chart illustrating a method of fabricating the semiconductor device illustrated in  FIG.  15   , according to various example embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various example embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, example embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, example embodiments are merely described below, by referring to the figures, to explain aspects. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. 
     Hereinafter, various example embodiments will be described in detail with reference to the accompanying drawings. In the drawings below, like reference numbers denote like constituent elements, and the sizes of components in the drawings may be exaggerated for convenience of explanation. Various embodiments described below are merely examples, and various modifications and changes are available from the embodiments. 
     When a constituent element is disposed “above” or “on” to another constituent element, the constituent element may include not only an element directly contacting on the upper/lower/left/right sides of the other constituent element, but also an element disposed above/under/left/right the other constituent element in a non-contact manner. An expression used in a singular form in the specification also includes the expression in its plural form unless clearly specified otherwise in context. When a part may “include” a certain constituent element, unless specified otherwise, it may not be construed to exclude another constituent element but may be construed to further include other constituent elements. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosure are to be construed to cover both the singular and the plural. Also, the steps of all methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The disclosure is not limited to the described order of the steps. 
     Furthermore, terms such as “. . . portion,” “. . . unit,” “. . . module,” and “. . . block” stated in the specification may signify a unit to process at least one function or operation and the unit may be embodied by hardware, software, or a combination of hardware and software. 
     Furthermore, the connecting lines, or connectors shown in the various figures presented are intended to represent functional relationships and/or physical and/or logical couplings between the various elements. It should be noted that many alternative or additional functional relationships, physical connections and/or logical connections may be present in a practical device. 
     The use of any and all examples, or language, e.g., “such as,” provided herein, is intended merely to better illuminate the disclosure and does not pose a limitation on the scope of the disclosure unless otherwise claimed. 
       FIG.  1    schematically illustrates a semiconductor device  100  according to various example embodiments. The semiconductor device  100  of  FIG.  1    may be or may include a field effect transistor (FET), such as an n-type FET (NFET) or a p-type FET (PFET), and may be planar or three-dimensional. 
     Referring to  FIG.  1   , the semiconductor device  100  may include a substrate  110 , a ferroelectric layer  140 , and a gate  150 . A paraelectric layer  130  may be provided between the substrate  110  and the ferroelectric layer  140 . 
     A channel layer  115  is integrally formed or integrally be part of or positioned at or near an upper portion of the substrate  110 . The channel layer  115  is provided in the upper portion of the substrate  110  corresponding to the gate  150 , and a source  121  and a drain  122  may be provided at opposite sides of the channel layer  115 . 
     The source  121  may be electrically connected to one side of the channel layer  115 , and the drain  122  may be electrically connected to the other side of the channel layer  115 . The source and drain  121  and  122  may be formed by doping or implant, e.g. injecting, impurities into different regions of the substrate  110 , and a region of the substrate  110  between the source  121  and the drain  122  may be defined as the channel layer  115 . Accordingly, the channel layer  115  may be provided integrally with or within the substrate  110 . However, as described below, a channel layer may be provided as a material layer separate from or at least partially separate from the substrate  110 , not as a part of or included in the substrate  110 . 
     The substrate  110  including the channel layer  115  may include a semiconductor material. For example, the substrate  110  may include, for example, one or more of Si, Ge, SiGe, a group III-V semiconductor, and the like. The substrate  110  may be formed from a Czochralski substrate and may be doped, e.g. may be lightly doped with one or more of boron, phosphorus, or arsenic during the Czochralski process; however, example embodiments are not limited thereto, and the substrate  110  may be initially undoped. Furthermore, the substrate  110  may include at least one of, for example, an oxide semiconductor, a nitride semiconductor, an oxynitride semiconductor, a two-dimensional (2D) semiconductor material, quantum dots, or an organic semiconductor. The oxide semiconductor may include, for example, InGaZnO and the like, the 2D semiconductor material may include, for example, transition metal dichalcogenide (TMD) or graphene, and the quantum dots may include colloidal quantum dots, a nanocrystal structure, and the like. However, this is merely an example, and example embodiments are not limited thereto. 
     The substrate  110  including the channel layer  115  may include a dopant of a certain concentration. The dopant may include a p-type dopant or an n-type dopant. The p-type dopant may include, for example, a group III element such as B, Al, Ga, In, and the like, and the n-type dopant may include, for example, a group V element such as P, As, Sb, and the like. 
     A semiconductor substrate including the p-type dopant at a particular dopant concentration in the channel layer  115  may be used as or for the substrate  110 , and when the source and drain  121  and  122  include n-type impurities, the semiconductor device  100  having an NMOS structure may be implemented. A semiconductor substrate including the n-type dopant at a particular dopant concentration in the channel layer  115  may be used as the substrate  110 , and when the source and drain  121  and  122  include p-type impurities, the semiconductor device  100  having a PMOS structure may be implemented. 
     In the semiconductor device  100  according to various example embodiments, the substrate  110  including the channel layer  115  may have a doping concentration of, for example, 1×10 15  cm −3  to 1×10 21  cm −3  within the channel layer  115 . As a detailed example, the substrate  110  including the channel layer  115  may have a doping concentration within the channel layer of 1×10 15  cm −3  to 1×10 21  cm −3 . More specifically, the channel layer may have a doping concentration of greater than or equal to 1×10 15  cm −3  and less than or equal to 1×10 18  cm −3 . 
     The ferroelectric layer  140  is provided on the channel layer  115  of the substrate  110 . A ferroelectric has a spontaneous dipole (electric dipole), for example, spontaneous polarization, because an electric charge distribution in a unit cell is non-centrosymmetric in a crystallized material structure. Furthermore, the ferroelectric has remnant polarization by a dipole when there is no external electric field. In the ferroelectric, the direction of polarization may be switched to a domain unit by an external electric field. 
     The ferroelectric layer  140  may include, for example, a fluorite-based material and/or a perovskite based material, and the like. The perovskite material may include, for example, PZT, BaTiO 3 , PbTiO 3 , and the like. The fluorite-based material may include, for example, at least one oxide selected from among Hf, Si, Al, Zr, Y, La, Gd, and Sr. 
     As a detailed example, the ferroelectric layer  140  may include at least one of a hafnium oxide (HfO), a zirconium oxide (ZrO), or a hafnium-zirconium oxide (HfZrO). The hafnium oxide (HfO), the zirconium oxide (ZrO), and the hafnium-zirconium oxide (HfZrO) constituting or included in the ferroelectric layer  140  may have a crystal structure of an orthorhombic crystal system. The ferroelectric layer  140  may further include a dopant of, for example, at least one of Si, Al, La, Y, Sr, or Gd. However, the materials stated below are merely an example, and various other materials may be used as the ferroelectric layer  140 . 
     The paraelectric layer  130  may be provided between the channel layer  115  of the substrate  110  and the ferroelectric layer  140 . The paraelectric layer  130  may include, for example, at least one of a silicon oxide, a silicon nitride, an aluminum oxide, a silicon oxynitride, a lanthanum oxide, or an yttrium oxide. However, example embodiments are not limited thereto. 
     The gate  150  is provided on the ferroelectric layer  140 . The gate  150  may be arranged facing the channel layer  115  of the substrate  110 . The gate  150  may include, for example, a conductive material such as one or more of a metal, a metal nitride, polysilicon such as doped polysilicon, a 2D conductive material, and the like. 
     In the semiconductor device  100  according to various example embodiments, as the ferroelectric layer  140  is formed between the channel layer  115  and the gate  150 , subthreshold swing (SS) of the semiconductor device  100  may be reduced by voltage amplification according to a negative capacitance effect. 
       FIG.  2    is a graph showing an effect of improving the subthreshold swing (SS) characteristics of the semiconductor device  100  of  FIG.  1   . In  FIG.  2   , “C 1 ” indicates the characteristics of an operating voltage Vg and a current Id of an existing silicon-based field effect transistor, and “C 2 ” indicates the characteristics of the operating voltage Vg and the current Id of the semiconductor device (the semiconductor device  100 ) of  FIG.  1   . 
     Referring to  FIG.  2   , for the existing silicon-based transistor, the SS is known to have a limit of about 60 mV/dec. However, as the semiconductor device  100  according to various example embodiments of  FIG.  1    uses the ferroelectric layer  140 , voltage amplification is generated by the negative capacitance effect, and accordingly, the SS may be reduced to about 60 mV/dec or less. Accordingly, by amplifying a voltage applied to the semiconductor device  100 , low-power driving may be possible and/or the semiconductor device  100  may be downscaled. 
     In a ferroelectric semiconductor device, when the doping concentration of a channel layer increases, remnant polarization P r  and coercive voltage V c  increase, and in this case, the degradation of a ferroelectric may be accelerated occurring, for example, from repeated cycles of programming and erasing. In the semiconductor device  100  according to various example embodiments, by having a lower doping concentration of a channel layer from 1×10 15  cm −3  to 1×10 21  cm −3  compared with the doping concentration of the existing ferroelectric semiconductor device, the remnant polarization and the coercive voltage may be maintained low, and accordingly, a low-voltage operation may be effectively implemented, and the reliability of a device according to the repeated programming and erasing may be improved. 
       FIG.  3    is a graph schematically showing a hysteresis loop indicative of the polarization P-voltage V characteristics of a capacitor having a metal-ferroelectric-metal (MFM) structure and a capacitor having a metal-ferroelectric-insulator-metal (MFIM) structure. Hafnium-zirconium oxide (HfZrO) may be the ferroelectric, and a silicon oxide may be the insulator. In  FIG.  3   , “H 1 ” indicates the polarization-voltage characteristics curve of an MFM structure, and “H 2 ” indicates the polarization-voltage characteristics curve of an MFIM structure. 
     Referring to  FIG.  3   , it may be seen that remnant polarization Pre and coercive voltage Vol of a capacitor having an MFIM structure are reduced compared with remnant polarization Po and coercive voltage V c1  of a capacitor having a metal-ferroelectric-metal (MFM) structure because the strength of an electric field applied to a ferroelectric (hafnium-zirconium oxide) is decreased due to the insertion of an insulator (silicon oxide). 
     In the semiconductor device  100  having a metal-ferroelectric-insulator-semiconductor (MFIS) structure according to various example embodiments, by reducing the doping concentration of the channel layer  115  of the substrate  110 , the strength of an electric field applied to the ferroelectric layer  140  may be reduced, and accordingly, the remnant polarization and the coercive voltage may be reduced. 
       FIG.  4    is a graph showing a simulation result of the polarization P-voltage V characteristics when the doping concentration of a channel layer in the semiconductor device  100  of  FIG.  1    is 1×10 20  cm −3  and 5×10 17 cm −3 . In this state, a hafnium-zirconium oxide (HfZrO) having a 7 nm thickness was used as the ferroelectric layer  140 , and a silicon oxide having a 1 nm thickness was used as the paraelectric layer  130 . Referring to  FIG.  4   , it may be seen that, by reducing the doping concentration of the channel layer  115 , the remnant polarization and the coercive voltage are reduced. 
       FIGS.  5 A to  5 C  are graphs showing experimental results of the polarization P-voltage V characteristics when the doping concentrations of a channel layer in the semiconductor device  100  of  FIG.  1    are 1×10 13  cm −3 , 1×10 14  cm −3  , and 1×10 15  cm −3 , respectively. In this state, a hafnium-zirconium oxide (HfZrO) having a  7  nm thickness was used as the ferroelectric layer  140 , and a silicon oxide having a  1  nm thickness was used as the paraelectric layer  130 . 
       FIG.  6    is a graph showing remnant polarization 2P r  and coercive voltage +V c  according to the doping concentration of the channel layer  115 , which is calculated based on the results shown in  FIGS.  5 A to  5 C . In  FIG.  6   , doping concentration N d  is expressed by the number of dopants per unit area. Referring to  FIG.  6   , it may be seen that, as the doping concentration of the channel layer  115  decreases, the remnant polarization 2P r  and the coercive voltage +V c  are reduced. 
     In the semiconductor device  100  according to various example embodiments, by making the doping concentration of the channel layer  115  be within a range of 1×10 15  cm −3  to 1×10 21 cm −3 , the remnant polarization 2P r  may be about 20 [μC/cm 2 ] or less, and the coercive voltage +V c  may be about 3[V] or less. 
     As described above, in the semiconductor device  100  according to various example embodiments, by making the doping concentration of the channel layer  115  be relatively lower than that of existing ferroelectric semiconductor device, the remnant polarization and/or the coercive voltage may be maintained low, and accordingly, the low-voltage operation may be more effectively implemented, and/or the reliability of a device according to the repeated programming and erasing may be improved. 
     The doping concentration of the channel layer  115  may be determined by various methods, such as but not limited to transmission electron microscopy (TEM) and/or secondary ion mass spectrometry (SIMS) such as time-of-flight SIMS (TOF-SIMS); however, example embodiments are not limited thereto. 
       FIG.  7    is a cross-sectional view of a semiconductor device  200  according to various example embodiments. The semiconductor device  200  of  FIG.  7    may be substantially the same as the semiconductor device  100  of  FIG.  1   , except that a channel layer  215  is provided separately from a substrate  210 . 
     Referring to  FIG.  7   , the semiconductor device  200  may include the substrate  210 , the channel layer  215 , a paraelectric layer  230 , a ferroelectric layer  240 , and a gate  250 . The channel layer  215  is provided on the substrate  210  corresponding to the gate  250 , and a source  221  and a drain  222  may be provided at opposite sides of the channel layer  215 . 
     The substrate  210  may include various materials. The channel layer  215  is provided on (e.g. directly on) an upper surface of the substrate  210 . The channel layer  215  may be provided as a material layer separate from the substrate  210 . The channel layer  215  may include at least one of, for example, an oxide semiconductor, a nitride semiconductor, an oxynitride semiconductor, a 2D material, quantum dots, or an organic semiconductor. 
     The channel layer  215  may include a dopant of a certain concentration. The dopant may include, for example, a p-type dopant including a group III element such as B, Al, Ga, In, and the like or an n-type dopant including a group V element such as P, As, Sb, and the like. The channel layer  215  may have, for example, a doping concentration of 1×10 15  cm −3  to 1×10 21  cm −3 . As a detailed example, the channel layer  215  may have a doping concentration of 1×10 15  cm −3 to 1×10 21  cm −3 . 
     The source  221  and the drain  222  may be provided at opposite sides of the channel layer  215 . The source  221  may be provided to be connected to one side of the channel layer  215 , and the drain  222  may be provided to be connected to the other side of the channel layer  215 . The source and drain  221  and  222  may include a conductive material and may include the same, or different materials. The paraelectric layer  230 , the ferroelectric layer  240 , and the gate  250  are sequentially stacked on and above the channel layer  215 , which is described above, and thus detailed descriptions thereof are omitted. 
     In various example embodiments as described above, the semiconductor devices  100  and  200 , in which the channel layers  115  and  215  have a sheet or planar channel structure, are described as examples. However, the disclosure is not limited thereto, and a semiconductor device, in detail, a fin-FET, in which the channel layer has a fin channel structure, or a semiconductor device, in detail, a gate-all-around-FET, in which the channel layer has a gate-all-around channel structure, may be provided. 
       FIG.  8    is a perspective view of a semiconductor device  300  according to various example embodiments.  FIG.  9    is a cross-sectional view taken along line A-A′ of  FIG.  8   ; 
     Referring to  FIGS.  8  and  9   , a source  321  and a drain  322  are provided at opposite sides above a substrate  310 , and a region of the substrate  310  between the source  321  and the drain  322  may be defined as a channel layer  315 . The channel layer  315  may have a fin shape. The channel layer  315 , like the substrate  110  including the channel layer  115  according to various example embodiment described above, may have a doping concentration of 1×10 15  cm −3  to 1×10 21  cm −3 . A gate  350  may be arranged to intersect with the channel layer  315  having a fin shape. A paraelectric layer  330  and a ferroelectric layer  340  may be provided between the channel layer  315  and the gate  350  to sequentially surround the channel layer  315 . 
       FIG.  10    is a perspective view of a semiconductor device  400 , in detail, a gate-all-around-FET, according to another embodiment.  FIG.  11    is a cross-sectional view taken along line B-B′ of  FIG.  10   . 
     Referring to  FIGS.  10  and  11   , a channel layer  415  may be provided between a source  421  and a drain  422 , and the channel layer  415  may have a shape of, for example, a sheet, a wire, and the like. The channel layer  415  may have a doping concentration of 1×10 15  cm −3  to 1×10 21  cm −3 , as described above. The source  421 , the drain  422 , and the channel layer  415  may be arranged apart from a substrate  410 . A gate  450  may be arranged to surround the channel layer  415  while intersecting with the source  421 , the drain  422 , and the channel layer  415 . A paraelectric layer  430  and a ferroelectric layer  440  may be provided between the channel layer  415  and the gate  450  to sequentially surround the channel layer  415 . 
     According to another aspect, a semiconductor apparatus including the semiconductor devices  100 ,  200 ,  300 , and  400  described above may be provided. The semiconductor apparatus may include a plurality of semiconductor devices, and may be in the form in which a field effect transistor and a capacitor are electrically connected to each other. The semiconductor apparatus may have memory properties, for example, a dynamic random access memory (DRAM) device and the like. 
       FIG.  12    is a cross-sectional view of a semiconductor apparatus D 10  according to various example embodiments. 
     Referring to  FIG.  12   , the semiconductor apparatus D 10  may have a structure in which a field effect transistor or semiconductor device  100  and a memory element such as a two-terminal electrical component such as a capacitor  500  and/or a memristor are electrically connected to each other via a contact  62 .  FIG.  12    illustrates an example in which the semiconductor device  100  of  FIG.  1    may be used as the semiconductor device  100 . However, this is merely an example, and the semiconductor device  200  of  FIG.  7   , the semiconductor device  300  (fin-FET) of  FIG.  8   , or the semiconductor device  400  (gate-all-around-FET) of  FIG.  10    may be used. 
     The capacitor  500  may include first and second electrodes  510  and  520  and a dielectric layer  530  provided between the first and second electrodes  510  and  520 . One of the first and second electrodes  510  and  520  of the capacitor  500  may be electrically connected to one of the source and drain  121  and  122  of the field effect transistor or semiconductor device  100  via the contact  62 . The contact  62  may include an appropriate conductive material, for example, one or more of tungsten, copper, aluminum, polysilicon, and the like. The capacitor  500  may be a linear capacitor, or may alternatively be a memristor memory element; however, example embodiments are not limited thereto. 
     The arrangement of the field effect transistor/semiconductor device  100  and the capacitor  500  may be variously changed. For example, the capacitor  500  may be arranged above the substrate  110  or may have a structure that is embedded in the substrate  110 . 
     The semiconductor apparatus D 10  described above may be applied to various electronic apparatuses. For example, the semiconductor apparatus D 10  described above may be used for one or more of an arithmetic operation, program execution, temporary data retention, and the like in an electronic apparatus such as a mobile device, a computer, a notebook computer, a sensor, a network device, a neuromorphic device, and the like. 
       FIGS.  13  and  14    are schematic conceptual views showing a device architecture that is applicable to an electronic apparatus according to various example embodiments. 
     Referring to  FIG.  13   , an electronic device architecture  1000  may include a memory unit  1010 , an arithmetic logic unit (ALU)  1020 , and a control unit  1030 . The memory unit  1010 , the ALU  1020 , and the control unit  1030  may be electrically connected to one another. For example, the electronic device architecture  1000  may be implemented as one chip including the memory unit  1010 , the ALU  1020 , and the control unit  1030 . In detail, the memory unit  1010 , the ALU  1020 , and the control unit  1030  may be mutually connected by a metal line in an on-chip to directly communicate with one another. The memory unit  1010 , the ALU  1020 , and the control unit  1030  may be monolithically integrated on one substrate, thereby constituting one chip. An input/output device  2000  may be connected to the electronic device architecture  1000 . 
     Each of or at least one of the memory unit  1010 , the ALU  1020  and the control unit  1030  may independently include the semiconductor devices described above such as a field effect transistor, a capacitor and/or other passive device such as a memristor, and the like. For example, each of the ALU  1020  and the control unit  1030  may independently include the field effect transistor described above, and the memory unit  1010  may include the capacitor, field effect transistor, or a combination thereof, as described above. The memory unit  1010  may include both a main memory and a cache memory. The electronic device architecture  1000  may be an on-chip memory processing unit. 
     Referring to  FIG.  14   , a cache memory  1510 , an ALU  1520 , and a control unit  1530  may constitute a central processing unit (CPU)  1500 . The cache memory  1510  may be static random access memory (SRAM) and may include the field effect transistor described above. Aside from the CPU  1500 , a main memory  1600  and an auxiliary storage  1700  may be provided. The main memory  1600  may be DRAM and may include the capacitor described above. In some cases, the electronic device architecture  1000  may be implemented in the form in which computing unit devices and memory unit devices are adjacent to each other, in one chip, regardless of sub-units. 
       FIG.  15    is a cross-sectional diagram illustrating a semiconductor device according to some example embodiments.  FIG.  15    may include some or all of the features of  FIG.  1   , and additional components are described. 
     Referring to  FIG.  15   , a semiconductor device  100  may include a substrate  110 , a ferroelectric layer  140 , and a gate  150 . A paraelectric layer  130  may be provided between the substrate  110  and the ferroelectric layer  140 . 
     The semiconductor device  100  may also include a spacer  160  on a sidewall of each of or at least one of the ferroelectric layer  140 , the gate  150 , and the paraelectric layer  130 . The spacer may be or may include a nitride, such as silicon nitride; however, example embodiments are not limited thereto. 
     The semiconductor device  100  may further include a first lightly doped drain (LDD)  123  within the substrate  110 , under the spacer  160 , and between the channel  115  and the source  121 . The first LDD  123  may include dopants at an impurity concentration less than that of the source  121 . The dopants included in the first LDD  123  may be of the same conductivity type as dopants included in the source  121 ; however, example embodiments are not limited thereto. 
     The semiconductor device  100  may further include a second lightly doped drain (LDD)  124  within the substrate  110 , under the spacer  160 , and between the channel  115  and the drain  122 . The second LDD  124  may include dopants at an impurity concentration less than that of the drain  122 . The dopants included in the second LDD  124  may be of the same conductivity type as dopants included in the drain  122 ; however, example embodiments are not limited thereto. 
     The semiconductor device  100  may further include first and second halo or pocket regions  125  and  126 . The first and second halo or pocket regions  125  and  126  may be doped with impurities of the conductivity type opposite to that of the source  121  and the drain  122 ; however, example embodiments are not limited thereto. 
       FIG.  16    is a flow diagram illustrating a method of fabricating the semiconductor device  100  described above. 
     Referring to  FIG.  16   , initially a substrate  110  may be provisioned (S 160 ). Upon provisioning the substrate  110 , the substrate  110  may be implanted, for example, with first dopants at a first dose (S 161 ). 
     The dose of the first dopants may be such that the channel layer  115  is formed within the substrate  110  at a concentration of greater than or equal to 1×10 15  cm −3  and less than or equal to 1×10 21  cm −3 . The implantation may be performed with a beamline implantation tool, and/or a plasma assisted doping tool, and may be performed one time or several times at the same dose or different doses and at the same energy or different energies. 
     A ferromagnetic layer  140  may be deposited on the channel layer  115  (S 162 ). For example the ferromagnetic layer may be deposited with a chemical vapor deposition (CVD) process; however, example embodiments are not limited thereto. 
     The source and drain  121  and  122  may be formed (S 163 ). The source and the drain  121  and  122  may be formed after the ferromagnetic layer  140  is formed. For example, the source and the drain  121  and  122  may be formed with an implantation process. Dopants in the implantation process may be of opposite conductivity type to that used in S 161 ; however, example embodiments are not limited thereto. 
     In the ferroelectric semiconductor device according to the embodiments described above, by making the doping concentration of a channel layer relatively lower than the doping concentration of the existing ferroelectric semiconductor device, the remnant polarization value and the coercive voltage may be maintained low, and accordingly, a low-voltage operation may be more effectively implemented, and/or the reliability of a device according to repeated cycles of programming and erasing may be improved. 
     Any of the elements and/or functional blocks disclosed above may include or be implemented in processing circuitry such as hardware including logic circuits; a hardware/software combination such as a processor executing software; or a combination thereof. For example, the processing circuitry more specifically may include, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a System-on-Chip (SoC), a programmable logic unit, a microprocessor, application-specific integrated circuit (ASIC), etc. The processing circuitry may include electrical components such as at least one of transistors, resistors, capacitors, etc. The processing circuitry may include electrical components such as logic gates including at least one of AND gates, OR gates, NAND gates, NOT gates, etc. 
     It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each variously described example embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.