Vertical-cavity surface-emitting transistor laser, t-vcsel and method for producing the same

A method for producing a transistor vertical-cavity surface-emitting laser, T-VCSEL, the method comprising:

• depositing a bottom distributed Bragg reflector, bottom DBR, on a substrate;
• depositing, on the bottom DBR, a p-doped collector layer;
• depositing a base layer, part of which is n-doped and comprises a light-emitting active layer, on top of the p-doped collector layer;
• depositing a first p-doped layer and a second p-doped layer on top of the base layer;
• etching away a volume through the second p-doped layer, thereby creating a central mesa region;
• covering the central mesa region with a masking material preventing epitaxial regrowth;
• growing, by epitaxial regrowth, an n-doped layer on a peripheral region of the first p-doped layer surrounding the central mesa region;
• removing the masking material from the top of the central mesa region;
• growing, by epitaxial regrowth, a third p-doped layer over both the central mesa region and the n-doped layer;
• etching away a volume through the third p-doped layer, the n-doped layer, the first p-doped layer, the base layer and partly through the p-doped collector layer, thereby exposing part of the p-doped collector layer;
• etching away a volume through the third p-doped layer, the n-doped layer, the first p-doped layer and partly through the base layer above the light-emitting active layer, thereby exposing part of the base layer;
• attaching an electrical contact on the exposed part of the p-doped collector layer, and an electrical contact on the third p-doped layer;
• attaching an electrical contact on the exposed part of the base layer;
• and
• depositing a top distributed Bragg reflector, top DBR, on the third p-doped layer in such a way that the top DBR at least overlies the central mesa region.

A method for producing a transistor vertical-cavity surface-emitting laser, T-VCSEL, the method comprising:

• depositing a bottom distributed Bragg reflector bottom DBR, on a substrate;
• depositing, on the bottom DBR, a p-doped collector layer;
• depositing a base layer, part of which is n-doped and comprises a light emitting active layer, on top of the p-doped collector layer;
• depositing a p-doped layer on top of the base layer;
• depositing an n+p+ tunnel-junction bilayer on top of the p-doped layer;
• etching away a volume through the n+p+-tunnel-junction bilayer, thereby creating a central mesa region;
• growing, by epitaxial regrowth, an n-doped layer on a peripheral region of the p-doped layer and on top of the mesa region;
• etching away a volume through the n-doped layer, the p-doped layer, the base layer and partly through the collector layer, thereby exposing part of the collector layer;
• and
• etching away a volume through the n-doped layer, the p-doped layer and partly through the base layer above the light-emitting active layer, thereby exposing part of the base layer;
• attaching, an electrical contact on the exposed part of the collector layer, and an electrical contact on the n-doped layer;
• attaching an electrical contact on the exposed part of the base layer;
• and
• depositing a top distributed Bragg reflector, top DBR, on the n-doped layer, in such a way that the top DBR at least overlies the central mesa region.