Image Sensor with Low Refractive Index Grid for Angular Response Improvement

High angular response and sensitivity sensor scheme is demonstrated in a CMOS image sensor (CIS) with 0.8um pixel pitch which has a low refractive index grid (LRIG) for pixels isolation. The CIS with 500nm thickness LRIG provide higher angular response, sensitivity and edge performance. The angular response in red, green, and blue channel are 94.5%, 90.1%, and 93.5%. Comparing LRIG with composite metal-oxide grid (CMG) scheme, the normalized integrated sensitivity (-15° to 15°) at CIS center has improved by blue 8.5%, green 9.5%, and red 8.6%. Therefore, this proposed CIS scheme is more suitable for photo shooting in a dark environment.