Method and device for preventing zinc/iron interaction in a semiconductor laser

A method for forming a semiconductor laser comprising the steps of:

• forming a plurality of stacked layers over a substrate of a first type conductivity, at least one of said layers being capable of emitting light when excited;
• etching said plurality of stacked layers and said substrate to form a mesa stripe of a predetermined width on said substrate, said etching being performed by using at least a first mask layer and a second mask layer, said second mask layer being situated on top of said first mask layer;
• forming a first current blocking layer in contact with two sides of said mesa stripe;
• subsequently removing partially said first mask layer to obtain a partially removed first mask layer with a width not greater than said predetermined mesa width;
• forming a second current blocking layer of a first type conductivity on said first current blocking layer;
• removing said second mask layer and said partially removed first mask layer subsequent to said step of forming said second current blocking layer;
• and
• forming a burying layer of a second type conductivity over said mesa stripe and said second current blocking layer.