Solid-state imaging device, production method thereof, and electronic device

Abstract

Disclosed is a solid-state imaging device which includes a pixel section, a peripheral circuit section, a first isolation region formed with a STI structure on a semiconductor substrate in the peripheral circuit section, and a second isolation region formed with the STI structure on the semiconductor substrate in the pixel section. The portion of the second isolation region buried into the semiconductor substrate is shallower than the portion buried into the semiconductor substrate of the first isolation region, and the height of the upper face of the second isolation region is equal to that of the first isolation region. A method of producing the solid-state imaging device and an electronic device provided with the solid-state imaging devices are also disclosed.

1 . A solid-state imaging device, comprising:
 a pixel section;   a peripheral circuit section;   a first isolation region formed with a STI structure on a semiconductor substrate in the peripheral circuit section; and   a second isolation region formed with the STI structure on the semiconductor substrate in the pixel section, a portion thereof buried into the semiconductor substrate being shallower than a portion buried into the semiconductor substrate of the first isolation region, and a height of an upper face thereof being equal to that of the first isolation region.   
   
   
       2 . The solid-state imaging device according to  claim 1 , further comprising:
 an impurity implanted region formed at an interface between the second isolation region and a photoelectric conversion element of the pixel section.   
   
   
       3 . The solid-state imaging device according to  claim 1 , wherein
 a part of the photoelectric conversion element is underneath of the second isolation region.   
   
   
       4 . A method of producing a solid-state imaging device; comprising the steps of:
 forming a first trench in a portion where a first isolation region is to be formed in a peripheral circuit section on a semiconductor substrate, and a second trench in a portion where a second isolation region is to be formed in a pixel section on the semiconductor substrate, the second trench being shallower than the first trench;   forming an insulator layer over a structure including interiors of the first and second trenches, and   forming first and second isolation regions to have surface heights equal to each other through polishing the insulator layer.   
   
   
       5 . The method of producing a solid-state imaging device according to  claim 4 , wherein
 in the step of forming first and second isolation regions, the insulator layer is polished so that protrusion heights of the first and second isolation regions from surfaces of the semiconductor substrate is in a range from 0 to 40 nm.   
   
   
       6 . The method of producing a solid-state imaging device according to  claim 4 , wherein the step of forming first and second trenches includes:
 forming any one of the first and second trenches; and   forming subsequently any one of the second and first trenches.   
   
   
       7 . The method of producing a solid-state imaging device according to  claim 4 , wherein the step of forming first and second trenches includes:
 forming first and second trenches having a same depth by a simultaneous etching process; and   forming subsequently the first trench so as to be deeper than the second trench by an etching process.   
   
   
       8 . An electronic device, comprising:
 a solid-state imaging device;   an optical system configured to lead incident light to a photoelectric conversion element included in the solid-state imaging device; and   a signal processing circuit configured to process output signals from the solid-state imaging device;   the solid-state imaging device including,   a pixel section;   a peripheral circuit section;   a first isolation region formed with a STI structure on a semiconductor substrate in the peripheral circuit section; and   a second isolation region formed with the STI structure on the semiconductor substrate in the pixel section, a portion thereof buried into the semiconductor substrate being shallower than a portion buried into the semiconductor substrate of the first isolation region, and a height of an upper face thereof being equal to that of the first isolation region.   
   
   
       9 . The electronic device according to  claim 8 , wherein
 the solid-state imaging device includes an impurity implanted region formed in a vicinity of an interface between the second isolation region and a photoelectric conversion element of the pixel section.   
   
   
       10 . The electronic device according to  claim 9 , wherein
 a part of the photoelectric conversion element is underneath the second isolation region.