Patent ID: 7855094

Claim:
A method of manufacturing a photo-detector comprising: providing a compound semiconductor substrate; forming a multi-layer compound semiconductor layer on the compound semiconductor substrate, wherein forming the multi-layer compound semiconductor layer comprises: forming an n + -InP layer on the compound semiconductor substrate; forming an i-InGaAs layer on the n + -InP layer, forming an n-InGaAsP layer on the i-InGaAs layer, forming an n-InP layer on the n-InGaAsP layer, and forming a p + -InGaAsP layer on the n-InP layer; forming a number of p-n junction diodes at a desired portion of the multi-layer compound semiconductor layer wherein forming the p-n junction diodes comprises: forming a mask pattern on the p + -InGaAsP layer, so that a desired region of the p + -InGaAsP layer is exposed, forming a p + diffusion layer in the n-InP layer and the p + -InGaAsP layer by diffusing p-type impurities in the exposed region, and removing the mask pattern; and forming an isolation region by implanting impurities so as to surround each p-n junction diode.