Patterned mirror VCSEL with adjustable selective etch region
AssigneeMotorola, Inc.
InventorsPiotr Grodzinski, Michael S. Lebby, Hsing-Chung Lee
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Abstract
Patterned-mirrors for VCSELs are fabricated by forming a first mirror stack of a plurality of pairs of relatively high and low index of refraction layers, forming an active region of aluminum-free material on the first mirror stack, and forming a second mirror stack of a plurality of pairs of relatively high and low index of refraction layers. The second mirror stack includes first and second portions of materials selected to provide different rates of etching between the first and second portions. The second portion is selectively etched to the first portion by utilizing the first portion as an etch stop.
Claims14
A method of fabricating patterned mirror VCSELs comprising the steps of:
- forming a first mirror stack of a first conductivity type, the first mirror stack being formed of a plurality Of pairs of relatively high and low index of refraction layers:
- forming an active region on the first mirror stack;
- forming a second mirror stack of a second conductivity type on the active region, the second mirror stack being formed of a first portion including at least one pair of relatively high and low index of refraction layers positioned on the active region and a second portion including at least one pair of relatively high and low index of refraction layers positioned on the first portion to form a complete second mirror stack, the number of pairs of relatively high and low index of refraction layers in the first and second portions, combined, being sufficient to provide a required reflectivity for operation of the VCSEL, and the first and second portions including forming the first portion of alternate layers of InGaP and GaAs and the second portion of alternate layers of AlGaAs and GaAs selected to provide different rates of etching between the first and second portions to allow the second portion to be selectively etched with respect to the first portion;
- and
- selectively etching the second portion of the second mirror stack by utilizing the first portion as an etch stop.
A method of fabricating patterned-mirrors for VCSELs comprising the steps of:
- forming a first mirror stack of a first conductivity type, the first mirror stack being formed of a plurality of pairs of relatively high and low index of refraction layers of AlGaAs and GaAs;
- forming an active region on the first mirror stack, the active region being formed of aluminum-free material;
- forming a second mirror stack of a second conductivity type on the active region, the second mirror stack being formed of a first portion including at least one pair of relatively high and low index of refraction layers including InGaP and GaAs positioned on the active region and a second portion including at least one pair of relatively high and low index of refraction layers including AlGaAs and GaAs positioned on the first portion to form a complete second mirror stack, and the number of pairs of relatively high and low index of refraction layers in the first and second portions, combined, being sufficient to provide a required reflectivity for operation of the VCSEL;
- and
- selectively etching the second portion of the second mirror stack by utilizing the first portion as an etch stop.
A patterned mirror VCSEL comprising:
- a substrate;
- a first mirror stack of a first conductivity type positioned on the substrate, the first mirror stack being formed of a plurality of pairs of relatively high and low index of refraction layers of AlGaAs and GaAs;
- an active region positioned on the first mirror stack, the active region being formed of aluminum-free material;
- and
- a second mirror stack of a second conductivity type positioned on the active region, the second mirror stack being formed of a first portion including at least one pair of relatively high and low index of refraction layers including InGaP and GaAs and positioned on the active region and a second portion including at least one pair of relatively high and low index of refraction layers including AlGaAs and GaAs positioned on the first portion to form a complete second mirror stack, and the number of pairs of relatively high and low index of refraction layers in the first and second portions, combined, being sufficient to provide a required reflectivity for operation of the VCSEL;
- and
- the second portion of the second mirror stack being patterned to the first portion to define a lasing region.
Dependencies are inferred from the claim text.