Preparation and characterization of hydrogenated amorphous germanium and hydrogenated amorphous germanium-carbide thin films

Miscellaneous · Fri Jan 01 00:00:00 EST 1988

OSTI ID:7158906

Wu, H S

Hydrogenated amorphous germanium (a-Ge:H) and germanium carbide (a-Ge{sub 1{minus}x}C{sub x}:H) films were prepared by rf sputtering of a polycrystalline Ge target in a vacuum {approximately}4 {times} 10{sup {minus}7} Torr at various rf power, target-substrate distance, varying partial pressures of Ar, H{sub 2}, and C{sub 3}H{sub 8}, and flow rates. The vibrational and opto-electronic properties such as infrared (IR) absorption, optical gap, electron-spin-resonance (ESR) signals, and conductivities vary with deposition conditions. The photoconductivity, in particular, was carefully monitored as a function of the deposition conditions to optimize it. The concentration of Ge-H bonds and the optical gap generally decrease as P is increased. Results of annealing showed the enhanced segregation effect of Ge-C bonds {ge} 300{degree}C. The evolution of bonded hydrogen with temperature is studied. Deposition rates of a-Ge:H films are estimated and compared. The thermalization curve for a Ge target is constructed. Deposition rate was found to decrease exponentially with increasing target-substrate distances to decrease with increasing partial pressures of H{sub 2} and C{sub 3}H{sub 8} and increasing flow rates. Hydrogen incorporation markedly increased photoconductivity.

• Research Organization: Iowa State Univ. of Science and Technology, Ames, IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 7158906
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GERMANIUM
THIN FILMS
GERMANIUM CARBIDES
FABRICATION
BONDING
DEPOSITION
ELECTRO-OPTICAL EFFECTS
HIGH TEMPERATURE
HYDROGENATION
SEGREGATION
CARBIDES
CARBON COMPOUNDS
CHEMICAL REACTIONS
ELEMENTS
FILMS
GERMANIUM COMPOUNDS
JOINING
METALS
360104* - Metals & Alloys- Physical Properties
360204 - Ceramics
Cermets
& Refractories- Physical Properties