Semiconductor light-receiving device and method for manufacturing the same

Abstract

Disclosed is a semiconductor light-receiving device having high reproducibility and reliability. Also disclosed is a method for manufacturing a semiconductor light-receiving device. Specifically disclosed is a semiconductor light-receiving device 100 with a mesa structure wherein a light-absorbing layer 6 , an avalanche multiplication layer 4 and an electric-field relaxation layer 5 are formed on a semiconductor substrate 2 . The light-absorbing layer 6 , avalanche multiplication layer 4 and electric-field relaxation layer 5 exposed in the side wall of the mesa structure are protected by an SiN x film or an SiO y N z film. The hydrogen concentration in the side wall surface of the electric-field relaxation layer 5 is set at not more than 15%, preferably not more than 10% of the carrier concentration of the electric-field relaxation layer 5.

1 - 8 . (canceled) 
   
   
       9 . A semiconductor light-receiving device comprising:
 a mesa structure including a light absorbing layer, an electric-field relaxation layer, and an avalanche multiplication layer;   a SiN x  film or a SiO y N z  film for protecting lateral faces of the mesa structure, wherein a hydrogen concentration at least in a part of the mesa structure is not more than 15% of a carrier concentration in the electric-field relaxation layer.   
   
   
       10 . The semiconductor light-receiving device according to  claim 9 , wherein the hydrogen concentration at least in a part of the mesa structure is more preferably not more than 10% of the carrier concentration in the electric-field relaxation layer. 
   
   
       11 . The semiconductor light-receiving device according to  claim 9 , wherein the mesa structure is a III-V group semiconductor, and a p type impurity is at least one of a material selected from Be, Zn, Cd, Hg, Mg and C and an n type impurity is at least one of a material selected from Si, C, S, Se, Te and O. 
   
   
       12 . The semiconductor light-receiving device according to  claim 9 , wherein the mesa structure is a III-V group semiconductor, and
 a p type impurity is at least one of a material selected from Be, Zn, Cd, Hg, Mg and C and an n type impurity is at least one of a material selected from Si, C, S, Se, Te and O.   
   
   
       13 . The semiconductor light-receiving device according to  claim 9 , wherein the avalanche multiplication layer, the electric-field relaxation layer, and the light absorbing layer is formed over a semiconductor substrate in this order. 
   
   
       14 . The semiconductor light-receiving device according to  claim 9 , further comprising:
 a first cladding layer provided between the avalanche multiplication layer and the semiconductor substrate; and   a second cladding layer provided over the light absorbing layer.   
   
   
       15 . The semiconductor light-receiving device according to  claim 14 , wherein the SiN x  film or the SiO y N z  film is formed over lateral faces of the first and second cladding layer. 
   
   
       16 . 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; and   forming a SiN x  film or a SiO y N z  film using at least N 2  gas as a nitrogen source to a lateral face of the mesa semiconductor structure.   
   
   
       17 . The manufacturing method of a semiconductor light-receiving device according to  claim 16 , wherein the SiN x  film is formed using SiH 4  gas in addition to N 2  gas and the SiO y N z  film is formed using O 2  gas or N 2 O gas in addition to N 2  gas and SiH 4  gas. 
   
   
       18 . The manufacturing method of the semiconductor light-receiving device according to  claim 16 , wherein the SiN x  film or the SiO y N z  film is manufactured by an ECR method. 
   
   
       19 . The manufacturing method of the semiconductor light-receiving device according to  claim 17 , wherein the SiN x  film or the SiO y N z  film is manufactured by an ECR method. 
   
   
       20 . 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 SiN x  film or a SiO y N z  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.   
   
   
       21 . The manufacturing method of the semiconductor light-receiving device according to  claim 20 , wherein the SiN x  film is formed using N 2  gas or NH 3  gas and SiH 4  gas and the SiO y N z  film is formed using N 2  gas or NH 3  gas and SiH 4  gas and O 2  gas.