IP Library › Granted Patent US 12,650,538
Granted Patent B2
US 12,650,538 · App. 18/073,177 · Granted Jun 9, 2026

Method of producing large GaAs and GaP infrared windows

Inventors: Peter G. Schunemann (Hollis, NH); Kevin T. Zawilski (Arlington, MA)
Assignee: BAE Systems Information and Electronic Systems Integration Inc.
G02B1/02C30B25/18C30B29/42C30B29/44C30B31/06H05K9/0081H05K9/0094
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Quick Facts
Patent No.
US 12,650,538
App. No.
18/073,177
Filed
Dec 1, 2022
Granted
Jun 9, 2026
Kind
B2
Art Unit
2872
USPC
359/350
Abstract

IR window slabs of GaP greater than 4 inches diameter, and of GaAs greater than 8 inches diameter, are grown on a substrate using Hydride Vapor Phase Epitaxy (HVPE), preferably low pressure HVPE (LP-HVPE). Growth rates can be hundreds of microns per hour, comparable to vertical melt growth. GaAs IR windows produced by the disclosed method exhibit lower absorption than crystals grown from vertical melt near 1 micron, due to reduced impurities and reduced growth temperatures that limit the solubility of excess arsenic, and thereby reduce the “EL2” defects that cause high absorption near one micron in conventional GaAs boules. Silicon wafers can be used as HVPE substrates. For GaAs, layers of GaAsP that vary from 0% to 100% As can be applied to the substrate. EMI shielding can be applied by adding a dopant during the final stage of growth to provide a conductive GaAs or GaP layer.

Claims (8)

1 . An infrared window comprising a GaAs slab having a slab largest dimension that is greater than eight inches, said slab being formed from a substrate wafer of single crystal silicon to which at least one layer of GaAs has been applied by Hydride Vapor Phase Epitaxy (“HVPE”), the substrate wafer being removable from the slab.

2 . The infrared window of claim 1 , wherein the slab largest dimension is greater than 12 inches.

3 . The infrared window of claim 1 , wherein the slab is substantially round, having a slab diameter of greater than eight inches.

4 . The infrared window of claim 3 , wherein the slab diameter is greater than 12 inches.

5 . The infrared window of claim 1 , wherein the slab is at least 2 mm thick.

6 . The infrared window of claim 1 , further comprising an electrically conductive layer of doped GaAs or GaP applied to the slab.

7 . The infrared windows of claim 1 , wherein the substrate wafer is a wafer of single crystal silicon.

8 . The infrared window of claim 1 , further comprising an anti-reflective coating applied to the slab.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 8, 2022
From: SCHUNEMANN, PETER G.; ZAWILSKI, KEVIN T.
To: BAE SYSTEMS INFORMATION AND ELECTRONIC SYSTEMS INTEGRATION INC.
Reel/Frame 062031/0535 →
Continuity (1)
Related Publication 20240184015A1 · Jun 6, 2024
References Cited (29)
US 3944393A · Schierding · 1976 [cited by applicant]
US 4776971A · Mattera · 1988 [cited by examiner]
US 4778731A · Kraatz · 1988 [cited by applicant]
US 4939043A · Biricik · 1990 [cited by applicant]
US 5007979A · Mizuniwa · 1991 [cited by applicant]
US 5173443A · Biricik · 1992 [cited by applicant]
US 5824418A · Tully · 1998 [cited by applicant]
US 6287478B1 · Klocek · 2001 [cited by examiner]
US 10156023B2 · Schunemann · 2018 [cited by applicant]
US 12084791B2 · Schunemann · 2024 [cited by examiner]
US 12203192B2 · Reeves · 2025 [cited by examiner]
US 12302542B2 · Schunemann · 2025 [cited by examiner]
US 20030172870A1 · Liu · 2003 [cited by applicant]
US 20100219509A1 · He · 2010 [cited by applicant]
US 20110256693A1 · D'Evelyn · 2011 [cited by applicant]
US 20120031324A1 · Hiromura · 2012 [cited by applicant]
US 20120097092A1 · Zhu · 2012 [cited by applicant]
US 20120255484A1 · Zhu · 2012 [cited by applicant]
US 20140162441A1 · Preble · 2014 [cited by applicant]
US 20170362739A1 · Kajimoto · 2017 [cited by applicant]
US 20240183065A1 · Schunemann · 2024 [cited by examiner]
Jeremy B. Reeves et. al., Method of Optimizing the EMI Shielding and Infrared Transparency of GaAs IR Windows, patent application, filed Dec. 1, 2022, U.S. Appl. No. 18/072,931. [cited by applicant]
Peter G. Schunemann et. al., Method of Producing Large EMI Shielded GaAs Infrared Windows, patent application, filed Dec. 1, 2022, U.S. Appl. No. 18/073,179. [cited by applicant]
Peter G. Schunemann et. al., Method of Producing Large EMI Shielded GaAs and GaP Infrared Windows, patent application, filed Dec. 1, 2022, U.S. Appl. No. 18/073,183. [cited by applicant]
Peter G. Schunemann et. al., Method of Producing Large GaAs and GaP Infrared Windows, patent application, filed Dec. 1, 2022, U.S. Appl. No. 18/073,228. [cited by applicant]
Sotoodeh, M., A. H. Khalid, and A. A. Rezazadeh. “Empirical low-field mobility model for III-V compounds applicable in device simulation codes.” Journal of applied physics 87.6 dated Mar. 15, 2000): 2890-2900. [cited by applicant]
Stromberg, A., Bhargava, P., Xu, Z., Lourdudoss, S. and Sun, Y. (2021), Direct Heteroepitaxy and Selective Area Growth of GaP and GaAs on Si by Hydride Vapor Phase Epitaxy. Phys. Status Solidi A, dated Oct. 17, 2020 218… [cited by applicant]
Office Action for U.S. Appl. No. 18/073,179 mail date Sep. 10, 2024, 16 pages. [cited by applicant]
Notice of Allowance for U.S. Appl. No. 18/073,228 mail date 240930, 15 pages (Sep. 30, 2024). [cited by applicant]