Method and apparatus for producing VCSELS with dielectric mirrors and self-aligned gain guide
View Patent ↗The invention includes a method of fabricating a laser device, that includes: depositing a photoresist on epitaxially grown layers, patterning said photoresist to form an aperture area, depositing a dielectric material on said patterned photoresist, depositing a liftoff layer on said dielectric material, removing portions of said dielectric material and liftoff layer that border said aperture area, implanting regions of the epitaxially grown layers bordering said aperture area, and depositing a metal layer on said dielectric material. The invention also includes a device including: a substrate comprising epitaxial layers and an aperture area, a dielectric mirror formed on top of said aperture area and an implanted region within said epitaxial layers, said implanted region bordering said aperture area.
1. A method of fabricating a laser, said method comprising the steps of:
(a) depositing a photoresist on epitaxially grown layers;
(b) patterning said photoresist to form an aperture area;
(c) depositing a dielectric material on said patterned photoresist;
(d) depositing a liftoff layer on said dielectric material;
(e) removing portions of said dielectric material and liftoff layer that border said aperture area;
(f) implanting regions of the epitaxially grown layers bordering said aperture area, wherein said remaining portion of said dielectric material and said liftoff layer serve as an implantation guide; and
(g) depositing a metal layer on said dielectric material.
2. The method of claim 1 , wherein said epitaxially grown layers comprise a bottom semiconductor Distributed Bragg Reflector stack, an active region and a partial top semiconductor Distributed Bragg Reflector stack.
3. The method of claim 2 , wherein said top semiconductor Distributed Bragg Reflector stack contains material chosen from the group consisting of aluminum, gallium, arsenic, indium, phosphorus and combinations thereof.
4. The method of claim 3 , wherein said top semiconductor Distributed Bragg Reflector stack comprises alternating layers of aluminum gallium arsenide and aluminum arsenide.
5. The method of claim 4 , wherein said top semiconductor Distributed Bragg Reflector stack is doped.
6. The method of claim 2 , wherein said top semiconductor Distributed Bragg Reflector stack has forty individual layers or less.
7. The method of claim 6 , wherein said top semiconductor Distributed Bragg Reflector stack has twenty individual layers or less.
8. The method of claim 7 , wherein said top semiconductor Distributed Bragg Reflector stack has eleven individual layers or less.
9. The method of claim 8 , wherein said top semiconductor Distributed Bragg Reflector stack has seven individual layers or less.
10. The method of claim 1 , wherein said dielectric material is chosen from the group consisting of silicon dioxide, titanium dioxide, silicon nitride, and combinations thereof.
11. The method of claim 10 , wherein said dielectric material is chosen from the group consisting of silicon dioxide, titanium dioxide, and combinations thereof.
12. The method of claim 11 , wherein said dielectric material is silicon dioxide.
13. The method of claim 1 , wherein said laser is a vertical cavity surface emitting laser.
14. A laser resulting from the method of claim 1 .
15. A method of fabricating a laser, the method comprising the steps of:
forming a dielectric mirror on epitaxially grown layers in such a manner that the extent of the dielectric mirror is never larger than the laser aperture during fabrication, wherein the method of forming the dielectric mirror comprises:
depositing a photoresist on the epitaxially grown layers;
patterning the photoresist to form an aperture area;
depositing a dielectric material on the patterned photoresist;
depositing a liftoff layer on the dielectric material; and
removing portions of the dielectric material and liftoff layer that border the aperture area;
implanting regions of the epitaxially grown layers bordering the aperture, wherein the remaining portion of the dielectric material and the liftoff layer serve as an implantation guide; and
depositing a metal layer on the dielectric material.
16. The method of claim 15 , wherein the epitaxially grown layers comprise a bottom semiconductor Distributed Bragg Reflector stack, an active region and a partial top semiconductor Distributed Bragg Reflector stack.
17. The method of claim 15 , wherein the top semiconductor Distributed Bragg Reflector stack has eleven individual layers or less.
18. A method of fabricating a laser, the method comprising:
depositing a photoresist on epitaxially grown layers, wherein the epitaxially grown layers comprise:
a bottom semiconductor Distributed Bragg Reflector stack;
an active region; and
a partial top semiconductor Distributed Bragg Reflector stack, wherein the top semiconductor Distributed Bragg Reflector stack has twenty individual layers or less and contains material chosen from the group consisting of aluminum, gallium, arsenic, indium, phosphorus, and combinations thereof;
patterning the photoresist to form an aperture area;
depositing a dielectric material on the patterned photoresist, wherein the dielectric material is chosen from the group consisting of silicon dioxide, titanium dioxide, silicon nitride, and combinations thereof;
depositing a liftoff layer on teh dielectric material; and
removing portions of the dielectric material and liftoff layer that border the aperture area;
implanting with a damage implant regions of the epitaxially grown layers bordering the aperture but not penetrating the aperture, wherein the remaining portion of the dielectric material and the liftoff layer serve as an implantation guide; and
depositing a metal layer on teh dielectric material.
19. The method of claim 18 , wherein the top semiconductor Distributed Bragg Reflector stack has eleven individual layers or less.