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

Abstract

A solid-state imaging element including a phase difference detection pixel pair that includes first and second phase difference detection pixels is provided. In particular, each phase difference detection pixel of the first and second phase difference detection pixels includes a first photoelectric conversion unit arranged at an upper side of a semiconductor substrate and a second photoelectric conversion unit arranged within the semiconductor substrate. The first photoelectric conversion film may be an organic film. In addition, phase difference detection pixels may be realized without using a light shielding film.

It is claimed: 
     
         1 . A light detecting element comprising:
 a phase difference detection pixel pair including first and second phase difference detection pixels, each phase difference detection pixel of the first and second phase difference detection pixels including a first photoelectric conversion unit arranged at an upper side of a semiconductor substrate, wherein the first photoelectric conversion unit includes a first photoelectric conversion film sandwiched between an upper electrode and a lower electrode and the lower electrode comprises a first lower electrode and a second lower electrode surrounding the first lower electrode.   
     
     
         2 . The light detecting element of  claim 1 , wherein a majority of the photoelectric conversion unit of the first phase difference detection pixel is above a left portion of the second photoelectric conversion unit of the first phase difference detection pixel and a majority of the photoelectric conversion unit of the second phase difference detection pixel is above a right portion of the second photoelectric conversion unit of the first phase difference detection pixel. 
     
     
         3 . The light detecting element of  claim 2 , further comprising an insulating film disposed between two photoelectric conversion regions of the first photoelectric conversion unit of at least one of the first and second phase difference detection pixels. 
     
     
         4 . The light detecting element of  claim 3 , wherein a first of the two regions of the first photoelectric conversion unit is above a left portion of the second photoelectric conversion unit of the first phase difference detection pixel. 
     
     
         5 . The light detecting element of  claim 2 , wherein the first photoelectric conversion film includes an organic photoelectric conversion film. 
     
     
         6 . The light detecting element of  claim 5 , wherein the second photoelectric conversion unit includes an inorganic photoelectric conversion film disposed within the semiconductor substrate. 
     
     
         7 . The light detecting element of  claim 2 , wherein each of the first and second phase detection pixels includes a floating diffusion region configured to accumulate a charge from the first photoelectric conversion unit, the floating diffusion region located within the semiconductor substrate. 
     
     
         8 . The light detecting element of  claim 2 , wherein a portion of the lower electrode in each of the first and second phase detection pixels is connected to a semiconductor region of a predetermined potential. 
     
     
         9 . The light detecting element of  claim 8 , wherein the predetermined potential is a ground (GND) potential. 
     
     
         10 . The light detecting element of  claim 2 , wherein
 in a left-half region of the first photoelectric conversion unit of the first phase difference detection pixel, the lower electrode is in contact with the photoelectric conversion film,   in a right-half region of the first photoelectric conversion unit of the first phase difference detection pixel, the lower electrode is not in contact with the photoelectric conversion film,   in a right-half region of the first photoelectric conversion unit of the second phase difference detection pixel, the lower electrode is in contact with the photoelectric conversion film, and   in a left-half region of the first photoelectric conversion unit of the second phase difference detection pixel, the lower electrode is not in contact with the photoelectric conversion film.   
     
     
         11 . The light detecting element of  claim 10 , wherein
 in the right-half region of the first photoelectric conversion unit of the first phase difference detection pixel, the lower electrode is in contact with an interlayer film, and   in a left-half region of the first photoelectric conversion unit of the second phase difference detection pixel, the lower electrode is in contact with an interlayer film.   
     
     
         12 . The light detecting element of  claim 1 , wherein the second photoelectric conversion unit occupies a left-half portion of the first phase difference detection pixel, and wherein the second photoelectric conversion unit occupies a right-half portion of the second phase difference detection pixel. 
     
     
         13 . The light detecting element of  claim 12 , further comprising an image generation pixel including a first photoelectric conversion unit arranged at the upper side of the semiconductor substrate and configured to photoelectrically convert the first wavelength of light and a second photoelectric conversion unit arranged within the semiconductor substrate and configured to photoelectrically convert the second wavelength of light,
 wherein the second photoelectric conversion units of the first and second phase difference detection pixels are smaller than the second photoelectric conversion unit of the image generation pixel.   
     
     
         14 . The light detecting element of  claim 1 , further comprising a plurality of image generation pixels and a plurality of phase difference detection pixels, wherein the upper electrode is common to the plurality of image generation pixels and the plurality of phase difference detection pixels, and wherein the lower electrode is not common to the plurality of image generation pixels and the plurality of phase difference detection pixels. 
     
     
         15 . The light detecting element of  claim 1 , wherein each of the first and second phase difference detection pixels include a third photoelectric conversion unit configured to photoelectrically convert a third wavelength of light, and wherein the third photoelectric conversion unit is below the second photoelectric conversion unit. 
     
     
         16 . The light detecting element of  claim 15 , wherein the first photoelectric conversion unit photoelectrically converts green light, the second photoelectric conversion unit photoelectrically converts blue light, and the third photoelectric conversion unit photoelectrically converts red light. 
     
     
         17 . The light detecting element of  claim 1 , further comprising a light shielding film arranged between the first and second phase difference detection pixels. 
     
     
         18 . The light detecting element of  claim 17 , wherein the light shielding film transfers charge accumulated in the first photoelectric conversion unit to a floating diffusion region via a conductive plug and metal wiring. 
     
     
         19 . An electronic device comprising:
 a light detecting element including a phase difference detection pixel pair including first and second phase difference detection pixels, each phase difference detection pixel of the first and second phase difference detection pixels including a first photoelectric conversion unit arranged at an upper side of a semiconductor substrate and a second photoelectric conversion unit arranged within the semiconductor substrate, wherein the first photoelectric conversion unit includes a first photoelectric conversion film sandwiched between an upper electrode and a lower electrode and the lower electrode comprises a first lower electrode and a second lower electrode surrounding the first lower electrode; and   an optical unit configured to receive incident light and form an image on an imaging surface of the light detecting element.