Fabricating semiconductor devices, such as VCSELs, with an oxide confinement layer

A method for forming an at least partially oxidized confinement layer of a semiconductor device, the method comprising:

• forming a to-be-oxidized layer of a semiconductor device on a substrate, wherein the to-be-oxidized layer has a first surface and a second surface opposite the first surface;
• forming an exposed layer having a first surface and a second surface opposite the first surface such that the second surface of the exposed layer is immediately adjacent to the first surface of the to-be-oxidized layer, and such that the to-be-oxidized layer is disposed between the substrate and the exposed layer;
• etching the exposed layer, using a masking process on the exposed layer and before forming another semiconductor layer of the semiconductor device immediately adjacent to the first surface of the exposed layer, to form a pattern of holes that extend through the exposed layer at least to the first surface of the to-be-oxidized layer and not through the second surface of the to-be-oxidized layer, the first surface of the to-be-oxidized layer being a surface of the to-be-oxidized layer that is parallel to a level plane defined by a surface of the substrate that is closest to the exposed layer, each hole of the pattern of holes extending in a direction that is transverse to the level plane;
• and
• oxidizing, before forming the other semiconductor layer of the semiconductor device immediately adjacent to the first surface of the exposed layer, the to-be-oxidized layer through the pattern of holes by exposing the to-be-oxidized layer and the exposed layer of the semiconductor device to an oxidizing gas to form a confinement layer.