Patent ID: 11942328
Assignee: COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
Field: Optics (Instruments)
Classification: CPC H | IPC H

Claim 0:
1. A method for forming a distributed Bragg reflector on a quantum cascade laser, comprising:
providing a stack of III-V material-based layers, comprising at least one active region to emit monochromatic light radiation,
depositing a first masking layer on said stack,
forming first patterns in the first masking layer,
forming first trenches in the stack to a first depth D1 from the first masking patterns, said first trenches extending primarily in a first direction and being intended to form structures of the distributed Bragg reflector,
depositing a second masking layer at least inside the first trenches,
forming second patterns in the second masking layer on either side of the first patterns,
forming second trenches in the stack to a second depth D2, greater than the first depth D1, from the second masking patterns, said second trenches extending primarily in a second direction, perpendicular to the first direction to form sidewalls of the quantum cascade laser,
removing the second masking layer from inside the first trenches, and
filling said first trenches with at least one metal material,
wherein the method further includes
before depositing the second masking layer, forming a sacrificial interlayer at least inside the first trenches, and
before filling said first trenches with the at least one metal material and after removing the second masking layer from inside the first trenches, removing said sacrificial interlayer so as to remove, by lift-off, residues of the second masking layer remaining in the first trenches at the end of the step of removing the second masking layer from inside the first trenches.