Solid-state imaging device and method for manufacturing solid-state imaging device

Abstract

A plurality of optical sensors ( 4 ) are arranged in a surface region of a semiconductor substrate ( 6 ) in a matrix pattern, and electric charge generated by the optical sensors ( 4 ) is transferred by first and second transfer electrodes ( 12 and 14 ) embedded under the optical sensors ( 4 ). The semiconductor substrate ( 6 ) is constructed by laminating a support substrate ( 16 ) composed of silicon, a buffer layer ( 18 ), and a thin silicon layer ( 20 ) composed of single-crystal silicon. p− regions ( 26 ) (overflow barrier) and n-type regions ( 28 ) which function as transfer paths are formed under the optical sensors ( 4 ). The first and the second transfer electrodes ( 12 and 14 ) are disposed between the buffer layer ( 18 ) and the n-type regions ( 28 ), and an insulating film ( 30 ) is interposed between the n-type regions ( 28 ) and the first and the second transfer electrodes ( 12 and 14 ). In this structure, the light-receiving area is large since the transfer electrodes are not disposed in the front region. Accordingly, the sensitivity can be ensured even when the size of the optical sensors ( 4 ) is reduced for increasing the number of pixels.

1 .- 13 . (canceled)  
   
   
       14 . A solid-state imaging device comprising: 
 a silicon thin film;    a plurality of optical sensors provided in said silicon thin film, said optical sensors receiving light from a first side of said silicon thin film;    a plurality of first separation regions which are formed between the optical sensors;    an insulating film at least partly contacting said separation regions formed at a second side of the silicon film; and    electrodes separated from the silicon thin film by said insulating film at the side of the silicon thin film where said separation regions contact said insulating film, and wherein said electrodes transfer signal charges generated by said optical sensors.    
   
   
       15 . A solid-state imaging device according to claim  1 , wherein said first separation regions are formed along the transfer direction of said signal charges.  
   
   
       16 . A solid-state imaging device according to claim  1 , wherein a plurality of second separation regions which are perpendicular to said plurality of first separation regions are formed between adjacent optical sensors and the second separation regions are comprised of ion-implanted impurities.  
   
   
       17 . A solid-state imaging device according to claim  1 , further comprising a barrier overflow directly beneath each optical sensor which is at least substantially surrounded by the first and second separation regions.  
   
   
       18 . A solid-state imaging device according to claim  1 , wherein the electrodes are at least partially covered by a buffer layer.  
   
   
       19 . A method of manufacturing a solid-state imaging device comprising: 
 providing a silicon thin film;    forming a plurality of first separation regions;    forming a plurality of optical sensors provided in said silicon thin film, wherein the optical sensors are located between the first separation regions, said optical sensors receiving light from a first side of said silicon thin film;    forming an insulating film at least partly contacting said separation regions formed at a second side of the silicon film; and    forming electrodes separated from the silicon thin film by said insulating film at the side of the silicon thin film where said separation regions contact said insulating film, and wherein said electrodes transfer signal charges generated by said optical sensors.    
   
   
       20 . A method of manufacturing a solid-state imaging device according to  claim 19 , wherein said first separation regions are formed along the transfer direction of said signal charges.  
   
   
       21 . A method of manufacturing a solid-state imaging device according to  claim 19 , further comprising forming a plurality of second separation regions which are perpendicular to said plurality of first separation regions between adjacent optical sensors and the second separation regions are comprised of ion-implanted impurities.  
   
   
       22 . A method of manufacturing a solid-state imaging device according to  claim 19 , further comprising forming a barrier overflow directly beneath each optical sensor which is at least substantially surrounded by the first and second separation regions.  
   
   
       23 . A method of manufacturing a solid-state imaging device according to  claim 19 , wherein the electrodes are at least partially covered by a buffer layer.