Patent ID: 7161170

Claim:
An absorption region of an avalanche photodetector, said absorption region having a top and a bottom and including a P-type dopant impurity therein, such that k B ⁢ T q ⁢ ∂ ∂ x ⁢ ln ⁡ ( N A ⁡ ( x ) ) ≥ 3 ⁢ ⁢ kV ⁢ / ⁢ cm in which k β is the Boltzmann constant, T represents operating temperature of said photodetector in degrees Kelvin, q is the fundamental unit of charge, N A represents concentration of said P-type dopant impurity, and x represents distance from one of said top and said bottom, wherein a charge layer is interposed between said absorption layer and a multiplication region, and said charge layer is formed of substantially the same material as a first multiplication layer disposed adjacent said charge layer.