After a p-type cladding layer, an etching rate reducing layer and a p-type contact layer are formed in order on an n-type substrate, an etching mask is formed. Then, by using the etching mask, the p-type contact layer, the etching rate reducing layer and the p-type cladding layer are partially etched...http://www.google.com/patents/US20060186420?utm_source=gb-gplus-sharePatent US20060186420 - Semiconductor device such as semiconductor laser device and manufacturing method therefor, and optical transmission module and optical disk unit employing the semiconductor laser device
