Vertical cavity surface emitting laser and preparation method therefor

A VCSEL, comprising:

• a substrate, and a semiconductor epitaxial structure located on a side of the substrate, wherein the semiconductor epitaxial structure comprises an N-type ohmic contact layer, an N-type DBR layer, a quantum well layer, a P-type DBR layer, and a P-type ohmic contact layer which are sequentially laminated on the substrate, the semiconductor epitaxial structure comprises a trench, and a mesa structure surrounded by the trench, a portion of the N-type ohmic contact layer is exposed from the trench, the mesa structure comprises a current confinement layer, and the current confinement layer has an oxide aperture for forming a emitter region of the mesa structure;
• an N-type ohmic metal layer, wherein the N-type ohmic metal layer is located on a bottom of the trench, and a distance between the N-type ohmic metal layer and a sidewall of the trench is greater than zero;
• a first passivation layer, wherein the first passivation layer is located on a side of the semiconductor epitaxial structure away from the substrate and on a sidewall and a bottom of the trench, the first passivation layer comprises a first via and a second via, the N-type ohmic metal layer is exposed from the first via, the P-type ohmic contact layer in the mesa structure is exposed from the second via, and the first via and the second via are formed in a same etching process;
• and
• a first electrode layer, a P-type ohmic metal layer and a second electrode layer, wherein the first electrode layer is in contact with the N-type ohmic metal layer exposed from the first via, the P-type ohmic metal layer is in contact with the P-type ohmic contact layer exposed from the second via, the second electrode layer is located on a side of the P-type ohmic metal layer away from the P-type ohmic contact layer, and the first electrode layer, the P-type ohmic metal layer and the second electrode layer are formed in a same metal deposition process.