Abstract:
An AMOLED back plate includes a substrate on which a buffer layer and a poly-silicon section are sequentially formed. A source and a drain are respectively formed of P-type heavy doped micro silicon on the poly-silicon section that have edges facing and spaced from each other to define a channel therebetween. A gate isolation layer is formed on the buffer layer, the source, the drain and the channel. A gate is formed on the gate isolation layer and has opposite edges that face in directions toward the edges of the source and the drain. The opposite edges of the gate are spaced from the edges of the source and the drain by predetermined spacing distance in horizontal directions so as to prevent the gate from overlapping the source and the drain.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a divisional application of co-pending U.S. patent application Ser. No. 14/429,082, filed on Mar. 18, 2015. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a display technology field, and more particularly to a manufacture method of an AMOLED back plate and a structure thereof. 
         [0004]    2. The Related Arts 
         [0005]    In the display field, liquid crystal display (LCD), organic light emitting diode (OLED) and other panel display techniques have been gradually replaced the conventional cathode ray tube (CRT) displays. The OLED possesses many outstanding properties of self-illumination, low driving voltage, high luminescence efficiency, fast response, high clarity and contrast, near 180° view angle, wide range of working temperature, applicability of flexible display and large scale full color display. The OLED is considered as the most potential flat panel display technology. 
         [0006]    The OLED can be categorized as passive matrix OLED (PMOLED) and active matrix OLED (AMOLED) according to the driving types. Generally, the AMOLED comprises a low temperature poly-silicon (LTPS) drive back plate and an electroluminescence layer for being the self-illumination component. The low temperature poly-silicon possesses higher electron mobility. For the AMOLED, the LTPS material possesses advantages of high resolution, fast response, high brightness, high aperture ratio, low power consumption, et cetera. 
         [0007]    A structure of an AMOLED back plate according to prior art is shown in  FIG. 1 . The manufacture process of the AMOLED back plate generally is: 
         [0008]    step 1, deposing a buffer layer  200  on a glass substrate  100 ; 
         [0009]    step 2, deposing an amorphous silicon layer (a-Si) on the buffer layer  200 , and using the Laser process to make the amorphous silicon layer to be crystallized and converted to be a poly-silicon layer (Poly-Si); 
         [0010]    step 3, patterning the poly-silicon layer with photo and etch processes to form a first poly-silicon section  301  and a second poly-silicon section  303 ; 
         [0011]    step 4, deposing an N type heavy doped amorphous silicon layer N+a-Si on the buffer layer  200 , the first poly-silicon section  301  and the second poly-silicon section  303 , and implementing the photo process to define the position of a channel  400 , and etching to pattern the N type heavy doped amorphous silicon layer N+a-Si for forming a source/a drain  401  on the first poly-silicon section  301  and an electrode  403  on the second poly-silicon section  303  except an area corresponding to the channel  400 ; 
         [0012]    step 5, deposing and patterning the gate isolation layer  500  on the buffer layer  200 , the source/the drain  401  and the electrode  403 ; 
         [0013]    step 6, deposing and patterning a first metal layer on the gate isolation layer  500  to form a gate  601  and a metal electrode  603 , wherein the gate  601  is above the source/the drain  401  and partially overlaps the source/the drain  401  in a horizontal direction; 
         [0014]    step 7, sequentially forming an interlayer insulation layer  700 , a metal source/a metal drain  801 , a flat layer  900 , an anode  1000 , a pixel definition layer  1100  and a photo spacer  1200  on the gate isolation layer  500 , the gate  601  and the metal electrode  603  with deposition, photo and etch processes. 
         [0015]    The metal source/the metal drain  801  are electrically connected to the source/the drain  401 ; and the anode  1000  is electrically connected to the metal source/the metal drain  801 . 
         [0016]    The first poly-silicon section  301 , the source/the drain  401 , the gate  601  and the metal source/the metal drain  801  construct a drive TFT, and the second poly-silicon section  303 , the electrode  403  and the metal electrode  603  construct a storage capacitor. 
         [0017]    The drive TFT of the AMOLED back plate shown in  FIG. 1  is an NMOS, and the AMOLED panel may suffer image sticking more easily. Besides, the contact resistance between the source/the drain  401  formed with the N type heavy doped amorphous silicon layer N+a-Si and the first poly-silicon section  301  is higher, and thus, the conductive current of the drive TFT can be lower. In addition, the source/the drain  401  and the gate  601  partially overlap each other in the horizontal direction and this may cause a leakage current of the drive TFT to be excessively high. 
       SUMMARY OF THE INVENTION 
       [0018]    An objective of the present invention is to provide a manufacture method of an AMOLED back plate, which can improve the electrical property of a drive TFT to make a conductive current higher and a leakage current lower, and diminish image sticking for raising the display quality of the AMOLED. 
         [0019]    Another objective of the present invention is to provide an AMOLED back plate, which can improve the electrical property of the drive TFT to make a conductive current higher and a leakage current lower, and diminish image sticking for raising the display quality of the AMOLED. 
         [0020]    For realizing the aforesaid objectives, the present invention provides a manufacture method of an AMOLED back plate, which comprises sequentially deposing a buffer layer, an amorphous silicon layer on a substrate, and crystallizing and converting the amorphous silicon layer to be a poly-silicon layer, and patterning the poly-silicon layer, and then deposing a P type heavy doped micro silicon layer, and implementing a photo process to define a position of a channel, and etching the P type heavy doped micro silicon layer to form a source/a drain, and thereafter, sequentially forming a gate isolation layer, a gate, an interlayer insulation layer, a metal source/a metal drain, a flat layer, an anode, a pixel definition layer and a photo spacer; the source/the drain and the gate do not overlap in the horizontal direction and are mutually spaced. 
         [0021]    The manufacture method of the AMOLED back plate comprises the following steps: 
         [0022]    step 1, providing a substrate and deposing a buffer layer on the substrate; 
         [0023]    step 2, deposing an amorphous silicon layer on the buffer layer and implementing an excimer laser annealing process to the amorphous silicon layer to make the amorphous silicon layer crystallized and converted into a poly-silicon layer; 
         [0024]    step 3, patterning the poly-silicon layer with photo and etch processes to form a first poly-silicon section and a second poly-silicon section; 
         [0025]    step 4, deposing a P type heavy doped micro silicon layer on the buffer layer, the first poly-silicon section and the second poly-silicon section; implementing a photo process to define a position of a channel; and etching the P type heavy doped micro silicon layer to pattern the P type heavy doped micro silicon layer for forming a source/a drain on the first poly-silicon section and an electrode on the second poly-silicon section except an area corresponding to the channel; 
         [0026]    step 5, deposing and patterning a gate isolation layer on the buffer layer, the source/the drain and the electrode; 
         [0027]    step 6, deposing and patterning a first metal layer on the gate isolation layer to form a gate and a metal electrode; 
         [0028]    wherein the gate is above the channel and the source/the drain and the gate are mutually spaced with a certain distance in a horizontal direction; 
         [0029]    step 7, sequentially forming an interlayer insulation layer, a metal source/a metal drain, a flat layer, an anode, a pixel definition layer, and a photo spacer on the gate isolation layer, the gate and the metal electrode with deposition, photo and etch processes; 
         [0030]    wherein the metal source/the metal drain are electrically connected to the source/the drain; and the anode is electrically connected to the metal source/the metal drain; and 
         [0031]    wherein the first poly-silicon section, the source/the drain, the gate and the metal source/the metal drain construct a drive TFT, and the second poly-silicon section, the electrode and the metal electrode construct a storage capacitor. 
         [0032]    In the step 4, the P type heavy doped micro silicon layer is deposed by chemical vapor deposition (CVD). 
         [0033]    The mutually spaced distance of the source/the drain and the gate in the horizontal direction is 0.1-0.5 μm. 
         [0034]    A material of the gate is a stacked combination of one or more of molybdenum, titanium, aluminum and copper. 
         [0035]    A material of the buffer layer is silicon nitride, silicon oxide, or a combination thereof; and a material of the interlayer insulation layer is silicon oxide, silicon nitride or a combination thereof. 
         [0036]    A material of the anode is an indium tin oxide/silver/indium tin oxide compound thin film. 
         [0037]    The present invention further provides a structure of an AMOLED back plate, comprising a substrate, a buffer layer located on the substrate, a first poly-silicon section and a second poly-silicon section arranged in space on the buffer layer, a source/a drain and an electrode respectively located on the first poly-silicon section and the second poly-silicon section, a gate isolation layer located on the buffer layer, the source/the drain and the electrode, a gate and a metal electrode located on the gate isolation layer, and an interlayer insulation layer, a metal source/a metal drain, a flat layer, an anode, a pixel definition layer and a photo spacer, sequentially formed on the gate isolation layer, the gate and the metal electrode, wherein the metal source/the metal drain are electrically connected to the source/the drain and the anode is electrically connected to the metal source/the metal drain; 
         [0038]    wherein a material of the source/the drain is P type heavy doped micro silicon; a channel is located between the source/the drain; and the gate is above the channel and the source/the drain and the gate are mutually spaced in a horizontal direction; 
         [0039]    wherein the first poly-silicon section, the source/the drain, the gate and the metal source/the metal drain construct a drive TFT, and the second poly-silicon section, the electrode and the metal electrode construct a storage capacitor. 
         [0040]    The mutually spaced distance of the source/the drain and the gate in the horizontal direction is 0.1-0.5 μm. 
         [0041]    A material of the gate is a stacked combination of one or more of molybdenum, titanium, aluminum and copper; a material of the buffer layer is silicon nitride, silicon oxide, or a combination thereof; a material of the interlayer insulation layer is silicon oxide, silicon nitride or a combination thereof; and a material of the anode is an indium tin oxide/silver/indium tin oxide compound thin film. 
         [0042]    The present invention further provides a structure of an AMOLED back plate, comprising a substrate, a buffer layer located on the substrate, a first poly-silicon section and a second poly-silicon section arranged in space on the buffer layer, a source/a drain and an electrode respectively located on the first poly-silicon section and the second poly-silicon section, a gate isolation layer located on the buffer layer, the source/the drain and the electrode, a gate and a metal electrode located on the gate isolation layer, and an interlayer insulation layer, a metal source/a metal drain, a flat layer, an anode, a pixel definition layer and a photo spacer, sequentially formed on the gate isolation layer, the gate and the metal electrode, wherein the metal source/the metal drain are electrically connected to the source/the drain and the anode is electrically connected to the metal source/the metal drain; 
         [0043]    wherein a material of the source/the drain is P type heavy doped micro silicon; a channel is located between the source/the drain; the gate is above the channel, and the source/the drain and the gate are mutually spaced in a horizontal direction; 
         [0044]    wherein the first poly-silicon section, the source/the drain, the gate and the metal source/the metal drain construct a drive TFT, and the second poly-silicon section, the electrode and the metal electrode construct a storage capacitor; 
         [0045]    wherein the mutually spaced distance of the source/the drain and the gate in the horizontal direction is 0.1-0.5 μm; 
         [0046]    wherein a material of the gate is a stacked combination of one or more of molybdenum, titanium, aluminum and copper; a material of the buffer layer is silicon nitride, silicon oxide, or a combination thereof; a material of the interlayer insulation layer is silicon oxide, silicon nitride or a combination thereof; and a material of the anode is an indium tin oxide/silver/indium tin oxide compound thin film. 
         [0047]    The benefits of the present invention are as follows. The present invention provides a manufacture method of an AMOLED back plate, in which by deposing and patterning a P type heavy doped micro silicon layer to form a source/a drain, and making the source/the drain and a gate be mutually spaced in a horizontal direction, the contact resistance between the source/the drain and a first poly-silicon section can be reduced to improve the electrical property of a drive TFT to make a conductive current higher and a leakage current lower, and diminish image sticking for raising the display quality of the AMOLED. The present invention also provides a structure of an AMOLED back plate, in which by locating a source/a drain of which a material is P type heavy doped micro silicon such that the source/the drain and a gate are mutually spaced in a horizontal direction, the contact resistance between the source/the drain and a first poly-silicon section can be reduced to improve the electrical property of a drive TFT to make a conductive current higher and a leakage current lower, and diminish image sticking for raising the display quality of the AMOLED. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0048]    The technical solution and the beneficial effects of the present invention are best understood from the following detailed description with reference to the accompanying figures and embodiments. 
           [0049]    In the drawings: 
           [0050]      FIG. 1  is a diagram of an AMOLED back plate structure according to prior art; 
           [0051]      FIG. 2  is a flowchart of a manufacture method of an AMOLED back plate according to the present invention; 
           [0052]      FIG. 3  is a diagram of step 3 in the manufacture method of the AMOLED back plate according to the present invention; 
           [0053]      FIG. 4  is a diagram of step 4 in the manufacture method of the AMOLED back plate according to the present invention; 
           [0054]      FIG. 5  is a diagram of step 5 in the manufacture method of the AMOLED back plate according to the present invention; 
           [0055]      FIG. 6  is a diagram of step 6 in the manufacture method of the AMOLED back plate according to the present invention; and 
           [0056]      FIG. 7  is a diagram of step 7 in the manufacture method of the AMOLED back plate and a diagram of a structure of the AMOLED back plate according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0057]    For better explaining the technical solution and the effect of the present invention, the present invention will be further described in detail with the accompanying drawings and the specific embodiments. 
         [0058]    Referring to  FIGS. 2-7 , the present invention provides a manufacture method of an AMOLED back plate, comprising the following steps: 
         [0059]    step 1, providing a substrate  1  and deposing a buffer layer  2  on the substrate  1 . 
         [0060]    The substrate  1  is a transparent substrate. Preferably, the substrate  1  is a glass substrate or a plastic substrate. 
         [0061]    A material of the buffer layer  2  is silicon nitride (SiNx), silicon oxide (SiOx), or a combination thereof. 
         [0062]    step 2, deposing an amorphous silicon layer on the buffer layer  2 , and implementing an excimer laser annealing process to the amorphous silicon layer to make the amorphous silicon layer crystallized and converted into a poly-silicon layer. 
         [0063]    step 3, as shown in  FIG. 3 , patterning the poly-silicon layer with photo and etch processes to form a first poly-silicon section  31  and a second poly-silicon section  33 . 
         [0064]    step 4, as shown in  FIG. 4 , deposing a P type heavy doped micro silicon (P+micro-crystallized Si) layer P+uc-Si on the buffer layer  2 , the first poly-silicon section  31  and the second poly-silicon section  33  by chemical vapor deposition (CVD); implementing a photo process to define a position of a channel  40 ; and etching the P type heavy doped micro silicon layer P+uc-Si to pattern the P type heavy doped micro silicon layer P+uc-Si for forming a source/a drain  41  on the first poly-silicon section  31  and an electrode  43  on the second poly-silicon section  33  except an area corresponding to the channel  40 . 
         [0065]    step 5, as shown in  FIG. 5 , deposing and patterning a gate isolation layer  5  on the buffer layer  2 , the source/the drain  41  and the electrode  43 . 
         [0066]    step 6, as shown in  FIG. 6 , deposing and patterning a first metal layer on the gate isolation layer  5  to form a gate  61  and a metal electrode  63 . 
         [0067]    The gate  61  is located above the channel  40 , and the source/the drain  41  and the gate  61  are mutually spaced with a certain distance in a horizontal direction. Furthermore, the mutually spaced distance of the source/the drain  41  and the gate  61  in the horizontal direction is 0.1-0.5 μm. 
         [0068]    A material of the gate  61  and the metal electrode  63  is a stacked combination of one or more of molybdenum (Mo), titanium (Ti), aluminum (Al) and copper (Cu). 
         [0069]    step 7, as shown in  FIG. 7 , sequentially forming an interlayer insulation layer  7 , a metal source/a metal drain  81 , a flat layer  9 , an anode  10 , a pixel definition layer  11 , and a photo spacer  12  on the gate isolation layer  5 , the gate  61  and the metal electrode  63  with deposition, photo and etch processes. 
         [0070]    The metal source/the metal drain  81  are electrically connected to the source/the drain  41 ; and the anode  10  is electrically connected to the metal source/the metal drain  81 . 
         [0071]    A material of the interlayer insulation layer  7  is silicon oxide, silicon nitride or a combination thereof. A material of the anode  10  is an indium tin oxide/silver/indium tin oxide (ITO/Ag/ITO) compound thin film. 
         [0072]    The first poly-silicon section  31 , the source/the drain  41 , the gate  61  and the metal source/the metal drain  81  construct a drive TFT, and the second poly-silicon section  33 , the electrode  43  and the metal electrode  63  construct a storage capacitor. 
         [0073]    In the aforesaid manufacture method of the AMOLED back plate, the source/the drain  41  is obtained by deposing and patterning a P type heavy doped micro silicon layer P+uc-Si, and thus, the drive TFT is a P type TFT, and the AMOLED driven by the P type TFT can diminish image sticking to thus improve the display quality of the AMOLED. Further, the material property of the P type heavy doped micro silicon is more similar with that of the poly-silicon, and thus, the contact resistance between the source/the drain  41  and the first poly-silicon section  31  can be reduced to improve the electrical property of the drive TFT to make a conductive current higher. The source/the drain  41  and the gate  61  are mutually spaced in the horizontal direction with no overlapping area therebetween so as to make a leakage current of the drive TFT lower. 
         [0074]    Referring to  FIG. 7 , the present invention also provides a structure of an AMOLED back plate, which comprises a substrate  1 , a buffer layer  2  located on the substrate  1 , a first poly-silicon section  31  and a second poly-silicon section  33  arranged in space on the buffer layer  2 , a source/a drain  41  and an electrode  43  respectively located on the first poly-silicon section  31  and the second poly-silicon section  33 , a gate isolation layer  5  located on the buffer layer  2 , the source/the drain  41  and the electrode  43 , a gate  61  and a metal electrode  63  located on the gate isolation layer  5 , and an interlayer insulation layer  7 , a metal source/a metal drain  81 , a flat layer  9 , an anode  10 , a pixel definition layer  11  and a photo spacer  12  sequentially formed on the gate isolation layer  5 , the gate  61  and the metal electrode  63 . 
         [0075]    The metal source/the metal drain  81  are electrically connected to the source/the drain  41 . The anode  10  is electrically connected to the metal source/the metal drain  81 . The first poly-silicon section  31 , the source/the drain  41 , the gate  61  and the metal source/the metal drain  81  construct a drive TFT, and the second poly-silicon section  33 , the electrode  43  and the metal electrode  63  construct a storage capacitor. 
         [0076]    A material of the source/the drain  41  is P type heavy doped micro silicon (P+uc-Si). A channel  40  is located between the source/the drain  41 . The gate  61  is located above the channel  40 . The source/the drain  41  and the gate  61  do not overlap each other and are mutually spaced in a horizontal direction. Furthermore, the mutually spaced distance between the source/the drain  41  and the gate  61  in the horizontal direction is 0.1-0.5 μm. 
         [0077]    Specifically, the substrate  1  is a transparent substrate. Preferably, the substrate  1  is a glass substrate or a plastic substrate. A material of the gate  61  is a stacked combination of one or more of molybdenum, titanium, aluminum and copper. A material of the buffer layer  2  is silicon nitride, silicon oxide, or a combination thereof. A material of the interlayer insulation layer  7  is silicon oxide, silicon nitride or a combination thereof. A material of the anode  10  is an indium tin oxide/silver/indium tin oxide compound thin film. 
         [0078]    In the aforesaid structure of AMOLED back plate, the material of the source/the drain  41  is P type heavy doped micro silicon P+uc-Si, and thus, the drive TFT is a P type TFT, and the AMOLED driven by the P type TFT can diminish image sticking and thus improving the display quality of the AMOLED. Further, the material property of the P type heavy doped micro silicon is more similar with that of the poly-silicon, and thus, the contact resistance between the source/the drain  41  and the first poly-silicon section  31  can be reduced to improve the electrical property of the drive TFT to make a conductive current higher. The source/the drain  41  and the gate  61  are mutually spaced in the horizontal direction with no overlapping area therebetween so as to make a leakage current of the drive TFT lower. 
         [0079]    In conclusion, in the manufacture method of an AMOLED back plate of the present invention, by deposing and patterning a P type heavy doped micro silicon layer to form a source/a drain and making the source/the drain and a gate be mutually spaced in a horizontal direction, the contact resistance between the source/the drain and a first poly-silicon section can be reduced to improve the electrical property of the drive TFT to make a conductive current higher and a leakage current lower, and diminish image sticking for raising the display quality of the AMOLED. In a structure of an AMOLED back plate of the present invention, by locating a source/a drain of which a material is P type heavy doped micro silicon such that the source/the drain and a gate are mutually spaced from each other in a horizontal direction, the contact resistance between the source/the drain and a first poly-silicon section can be reduced to improve the electrical property of the drive TFT to make a conductive current higher and a leakage current lower, and diminish image sticking for raising the display quality of the AMOLED. 
         [0080]    The above provides only specific embodiments of the present invention, and the scope of the present invention is not limited to it. To those skilled in the art, modification or substitution that are easily derived should be covered by the protection scope sought for the invention. Thus, the scope of the invention should be defined by the appended claims.