RF plasma deposition of amorphous silicon-germanium alloys : evidence for a chemisorption-based growth process

• Published in: IEEE transactions on plasma science 1990-12, Vol.18 (6), p.934-939
• Main Authors: BRUNO, G, CAPEZZUTO, P, CICALA, G, MANODORO, P, TASSIELLI, V
• Format: Article
• Language: English
• Subjects: 360601 - Other Materials- Preparation & Manufacture; AMORPHOUS STATE; CHEMICAL REACTIONS; CHEMISORPTION; Cross-disciplinary physics: materials science; rheology; CRYSTAL GROWTH; DEPOSITION; ELECTRIC DISCHARGES; ELECTRIC PROBES; EMISSION SPECTROSCOPY; Exact sciences and technology; FLUORINE ADDITIONS; GERMANIUM COMPOUNDS; GERMANIUM SILICIDES; GLOW DISCHARGES; HYDROGEN ADDITIONS; IN-SITU PROCESSING; INTERFEROMETRY; LANGMUIR PROBE; LASERS; MASS SPECTROSCOPY; MATERIALS SCIENCE; Methods of crystal growth; physics of crystal growth; OPTICAL PROPERTIES; PHYSICAL PROPERTIES; Physics; PLASMA; PROBES; PROCESSING; RF SYSTEMS; SEPARATION PROCESSES; SILICIDES; SILICON COMPOUNDS; SORPTION; SPECTROSCOPY; Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; THIN FILMS
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/27.61506

Amorphous silicon-germanium alloys (a-Si{sub 1{minus}x}Ge{sub x}:H,F) have been deposited by glow-discharge decomposition of silicon tetrafluoride (SiF{sub 4}) and germane (GeH{sub 4}) in mixture with hydrogen. The effect of total RF power and deposition temperature on the characteristics of the gas phase and the grown material has been evaluated. Also, the effect of the dopant addition has been studied by adding PH{sub 3} and B{sub 2}H{sub 6} to the feeding mixture. The gas-phase characterization has been performed with optical emission spectroscopy (OES) for the analysis of the emitting species, mass spectrometry (MS) for the analysis of the stable species, and Langmuir electrical probes (LEP) for the evaluation of electron density (n{sub e}) and temperature (kT{sub e}). The deposition rate has been measured in-situ by laser interferometry (LI). The deposited films have been analyzed with IR and VIS absorption spectroscopy and with X-ray microanalysis for the measurement of the chemical composition and optical properties.