Method for growing crystalline optical films on Si substrates which may optionally have an extremely small optical loss in the infra-red spectrum with hydrogenation of the crystalline optical films

US12116662B2 · kind B2 · utility

Assignee

• HRL Laboratories, LLC · US

Inventors

• Kyung-Ah Son · Moorpark, US
• Jeong-Sun Moon · Moorpark, US
• Hwa Chang Seo · Torrance, US
• Richard Kremer · Poway, US
• Ryan G. Quarfoth · Los Angeles, US
• Jack A. Crowell · Camarillo, US
• Mariano J. Taboada · Malibu, US
• Joshua M. Doria · Malibu, US
• Terry B. Welch · Malibu, US

Key dates

• Filing date: Aug 18, 2022
• Grant date: Oct 15, 2024
• Expiry date: Oct 5, 2042

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C14/5846
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A process enables growing thick stoichiometric crystalline and preferably IR-transparent optical PCMO material on Si and other substrates. Sputter deposition is carried out in oxygen-free inert gas (e.g., Ar) environment, which helps to prevent decomposition of the PCMO material over the substrate. In the disclosed process, there is no need to add a seed layer prior to PCMO deposition. Moreover, no post-deposition annealing is needed in a high-temperature and high-pressure oxygen furnace, but an anneal provides certain additional benefits in terms of improved transparency at IR wavelengths. Over a long deposition time for a thick PCMO film on the high temperature (≥450° C.) substrates, the PCMO deposition is made repeated cycles of deposition of the PCMO material at the high temperature, each deposition cycle being followed by cooling the PCMO-deposited substrate to a substantially lower temperature (<50° C.). If an anneal is applied in a hydrogen environment that will cause hydrogenation of the PCMO film which yields PCMO films with an extremely small optical loss (i.e., optical extinction coefficient k<0.001) over the entire IR range.