Browse Prior Art Database

Protective Coating for GaAlAs LPE Surfaces

IP.com Disclosure Number: IPCOM000088972D
Original Publication Date: 1977-Aug-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Potemski, RM: AUTHOR [+2]

Abstract

An additional GaAlAs LPE (liquid phase epitaxy) layer is deposited during the growth processing of a GaAs-AlAs DH laser in order to protect the fragile underlying LPE surface during post-growth processing. This protective coating is etched away just before top-side processing is begun.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Protective Coating for GaAlAs LPE Surfaces

An additional GaAlAs LPE (liquid phase epitaxy) layer is deposited during the growth processing of a GaAs-AlAs DH laser in order to protect the fragile underlying LPE surface during post-growth processing. This protective coating is etched away just before top-side processing is begun.

The protective layer must be grown by LPE, must be removable by etching without damaging the underlying layers, and must be thick enough to protect the surface below from scratching and other mechanical and contamination damage. An LPE layer of Ga(1-x)Al(x)As, where x is in the range of 0.75 to 0.85 will satisfy these requirements and may be etched away with HCl.

The additional layer protects the underlying layers while the substrate is thinned to the desired final thickness.

In order to protect the back side during subsequent zinc or other diffusions into the top side, an Al(2)O(3) coating may be applied to the back side.

Just prior to top-side processing, the protective layer is removed by etching. This procedure also removes any undesirable growths resulting from droplets of Ga left behind during LPE.

The fragile wafer may be handled after thinning and zinc diffusion by mounting on a Si wafer using a low temperature solder, e.g., In-Sn.

1