Patent ID: 7141833

Claim:
A photodiode, comprising: a semiconductor substrate; a photosensitive region in the substrate, the photosensitive region having a space charge zone region for generating a drift current portion and a diffusion region for generating a diffusion current portion; and an insulator in the semiconductor substrate for at least partially confining the diffusion region from an adjacent surrounding region of the semiconductor substrate, wherein the semiconductor substrate is of a first conduction type, and the space charge zone region is formed by a signal region with a second connectivity type in the semiconductor substrate, which is different from the fist conductivity type, wherein the insulation means is formed by an insulation region of the second conductivity type in the semiconductor substrate at a predetermined spacing to the signal region, and wherein the semiconductor substrate comprises a doping profile having a doping density decreasing in depth direction, such that a bulging of a space charge zone of the insulation region in lower regions of the semiconductor substrate results.