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

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.