The formation and behavior of particle in silane discharges

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20107879

Gallagher, A

Particle growth in silane RF discharges, and the incorporation of particles into hydrogenated-amorphous-silicon (a-Si:H) devices is described. These particles have a structure similar to a-Si:H, but their incorporation into the device is believed to yield harmful voids and interfaces. Measurements of particle density and growth in a silane RF plasma, for particle diameters of 8--50 nm, are described. This particle growth rate is very rapid, and decreases in density during the growth indicate a major flux of these size particles to the substrate. Particle densities are a very strong function of pressure, film growth rate and electrode gap, increasing orders of magnitude for small increases in each parameter. A full plasma-chemistry model for particle growth from SiH{sub m} radicals and ions has been developed, and is outlined. It yields particle densities and growth rates, as a function of plasma parameters, which are in qualitative agreement with the data. It also indicates that, in addition to the diameter > 2 nm particles that have been observed in films, a very large flux of Si{sub x}H{sub m} molecular radicals with x >> 1 also incorporate into the film. It appears that these large radicals yield more than 1% of the film for typical device-deposition conditions, so this may have a serious effect on device properties.

• Research Organization: Univ. of Colorado, Boulder, CO (US); National Inst. for Standards and Technology, Boulder, CO (US)
• OSTI ID: 20107879
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
AMORPHOUS STATE
HIGH-FREQUENCY DISCHARGES
HYDROGEN ADDITIONS
PLASMA SIMULATION
SEMICONDUCTOR DEVICES
SILANES
SILICON
SURFACE COATING