Method for manufacturing a semiconductor light-receiving device

A manufacturing method of a mesa semiconductor light-receiving device including a light absorbing layer, an avalanche multiplication layer and an electric-field relaxation layer over a semiconductor substrate, the method comprising:

• forming a mesa semiconductor structure;
• forming a SiNx film or a SiOyNz film to a side wall surface of the mesa semiconductor structure;
• and
• performing a heat treatment in inert gas atmosphere at 450 degrees Celsius or more and 700 degrees Celsius or less.

A manufacture method of a mesa semiconductor light-receiving device, the method comprising:

• forming a mesa semiconductor structure on a semiconductor substrate, the mesa semiconductor structure including an avalanche multiplication layer, a electric-field relaxation layer, an absorbing layer, a cladding layer, and a contact layer are formed in this order from bottom;
• forming a SiNx film or a SiOyNz film using at least N2 gas as a nitrogen source of a plasma CVD (Chemical Vapor Deposition) to a lateral face of the mesa semiconductor structure;
• and
• performing a heat treatment in inert gas atmosphere at 450 degrees Celsius or more and 700 degrees Celsius or less.