Properties of reactively-deposited SiC and GeC alloys

Conference · Fri Jun 01 04:00:00 EDT 1990

OSTI ID:6952020

Martin, P M; Johnston, J W; Bennett, W D

Thin-film silicon carbide (Si{sub x}C{sub 1-x}) and germanium carbon (Ge{sub x}C{sub 1-x}) alloy coatings with low infrared optical absorption have been fabricated by dc- and rf-reactive magnetron sputtering. The optical and mechanical properties of the coatings depend on composition determined by deposition conditions. The refractive index and optical absorption coefficient of Si{sub x}C{sub 1-x} alloys were varied from those of amorphous SI to those near diamond-like carbon (DLC) by increasing C content. The band edge shifted below 1.2 eV with C content as high as 0.8. The useful range of the Si{sub x}C{sub 1-x} coatings was extended to wavelengths as low as 1 {mu}m. The useful transparency range of Ge{sub x}C{sub 1-x} coatings is from 3 to 12 {mu}m. The refractive index of Ge{sub x}C{sub 1-x} coatings was varied from 4.2 of amorphous Ge to near 3.4 by increasing x from 0 to 0.5. The optical absorption coefficient was a complex function of composition and C-H, Ge-H, and Ge-C bonding. Mechanical stress in both materials was generally moderate, and increased with increasing C content for the GeC alloys and decreased with increasing C or the SiC alloys. The wide range of optical properties obtainable for both coating types makes them useful in many types of multilayer designs. Abrasion-resistant infrared (IR) multispectral antireflection coatings on zinc sulfide (ZnS) were demonstrated using Ge{sub 0.9}C{sub 0.1} and DLC layers. 6 refs., 6 figs., 2 tabs.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• Sponsoring Organization: DOD; DOE/NE
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6952020
• Report Number(s): PNL-SA-17876; CONF-900756--35; ON: DE90016363
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
360104 -- Metals & Alloys-- Physical Properties
360203 -- Ceramics
Cermets
& Refractories-- Mechanical Properties
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
ALLOYS
ANTIREFLECTION COATINGS
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
COATINGS
GERMANIUM ALLOYS
GERMANIUM CARBIDES
GERMANIUM COMPOUNDS
INORGANIC PHOSPHORS
MECHANICAL PROPERTIES
OPTICAL PROPERTIES
PHOSPHORS
PHYSICAL PROPERTIES
SILICON CARBIDES
SILICON COMPOUNDS
SPUTTERING
SULFIDES
SULFUR COMPOUNDS
ZINC COMPOUNDS
ZINC SULFIDES