Patent ID: 6015721
Filing Date: 2000-01-18
Classification: H01L,Y02E

Abstract:
A method of manufacturing an avalanche photodiode comprising the steps of:forming an absorption layer, a grading layer, a charge sheet layer of a first conductivity type and a multiplying layer in sequence on compound semiconductor substrate of the first conductivity type;forming a concave portion within the multiplying layer at the central portion thereof;forming a first diffusion layer of a second conductivity type to a first depth within the multiplying layer so as to surround the concave portion; andforming a second diffusion layer of the second conductivity type within the multiplying layer to a second depth deeper than the first depth by extending the first diffusion layer and simultaneously with forming a floating guard-ring within the multiplying layer, separated from the second diffusion with a selected distance, whereby a junction face between the second diffusion layer and the multiplying layer is formed with a gentle grade at the edge portion of the junction face.