Surface emitting semiconductor laser and process for producing the same

A surface emitting semiconductor laser comprising:

• a substrate;
• semiconductor layers laminated on the substrate in turn, the semiconductor layers includes a first reflector having a first electrical conduction type, an active region on the first reflector, at least one current confinement partially including an oxide region, and a second electrical conduction type;
• a mesa at least extending from the second reflector to the current confinement region;
• and
• an insulating film that covers at least a bottom and a sidewall of the mesa,
• the bottom of the mesa covered by the insulating film being in the absence of an oxide region.

A surface emitting semiconductor laser comprising:

• a substrate;
• a first semiconductor multilayer reflector formed on the substrate;
• an active region formed on the first semiconductor multilayer reflector;
• a pair of spacer layers that sandwich the active layer;
• a second semiconductor multilayer reflector formed on the active region;
• a current confinement layer interposed between the first and second semiconductor multilayer reflectors and partially including an oxide region, a mesa structure ranging at least from the second semiconductor multilayer reflector to the current confinement layer being defined;
• and
• an insulating layer that covers at least a sidewall and a bottom of the mesa structure,
• the bottom of the mesa structure being provided by a first one of the pair of spacer layers that is in the absence of an oxide layer.

A process of producing a surface emitting semiconductor laser comprising the steps of:

• (a) forming, on a substrate, a first semiconductor multilayer reflector of a first electrically conducting type, an active region, at least one semiconductor layer that confines current, and a second semiconductor multilayer reflector of a second electrically conducting type;
• (b) forming, by etching, a mesa structure that includes at least the second semiconductor multilayer reflector and the at least one semiconductor layer;
• (c) partially oxidizing an exposed sidewall of the at least one semiconductor layer to thereby form a current confinement region;
• (d) removing, by etching, an oxide layer formed on a bottom of the mesa structure exposed by the step (b);
• and
• (e) forming an insulating film that covers the bottom and sidewall of the mesa structure.