Sony paper is named "High-saturation output 1.55-um-square pixel IT-CCD with metal wiring line structure in a pixel". What I was able to understand from Google translation, Sony used low temperature process to minimize diffusion and get more abrupt junction and increase the photodiode capacitance in small pixels.
Omnivision's paper is titled "The Mass Production of BSI CMOS Image Sensors: Performance Results". Google translation gives the following performance numbers for the pixels, as far as I can understand:
- 1.4um and 1.75um pixels BSI mass produced using bulk P-epi/P-sub
- 2-shared pixel design
- 110nm (FEOL) & 90nm (BEOL) process (1.4um pixel is 90nm/90nm)
- QE (R / Gb / Gr / B): 1.4um = 43.8/53.5/53.6/51.6%, 1.75um = 53.0/60.1/60.2/60.4
- Full Well: 1.4um = 4,500 e, 1.75um = 6,500 e
- SNR10: 1.4 um = 110Lux, 1.75um = 60Lux
- Both pixels have the read noise of 1-2e
- No Image Lag
- Dark Current is 22 ~ 27e / s @ 50C (80e/sec @ 60C)
Honestly, I was disappointed to see relatively low QE despite all the added process complexity. I doubt that switch to BSI is justifiable with these QE numbers. Obviously, QE is not the whole story, one needs to look at color crosstalk too. I'd guess the crosstalk is rather low, otherwise SNR10 of 110Lux would not be achieved.