High-deposition rate a-Si:H through VHF-CVD of argon-diluted silane

Conference · Tue Jul 01 04:00:00 EDT 1997

OSTI ID:20085520

Meiling, H; Bezemer, J; Schropp, R E.I.; Weg, W.F. Van Der

The authors discuss various ways to produce hydrogenated amorphous silicon, a-Si:H, at a high deposition rate. They also present results of their recent study on the structural properties of a-Si:H films deposited at high rates using argon (Ar) dilution of silane in a 50-MHz glow discharge. The results of the depositions with Ar dilution are compared to films deposited from pure silane, SiH{sub 4}. The deposition rate r{sub d} is changed by varying the rf power P{sub rf} into the discharge. They focus on the P{sub rf}-dependence of the hydrogen (H) bonding configuration and total H content in the film. It is observed that r{sub d} saturates the H bonding configuration changes from mostly isolated H to mostly clustered H, and back to mostly isolated H. It is argued that Ar* metastable atoms play an important role in the growth mechanism at intermediate P{sub rf}, whereas at high P{sub rf} ion bombardment through Ar{sup +} and SiH{sub x}{sup +} (x {le} 3) ions becomes crucial. Two high-rate a-Si:H films are incorporated in thin-film transistors, TFTs. They present their characteristics before and after illumination with calibrated light. It is shown that a-Si:H TFTs with a saturation mobility of 0.7 cm{sup 2}/vs can be fabricated, with the complete intrinsic layer deposited at 20 {angstrom}/s.

• Research Organization: Utrecht Univ. (NL)
• OSTI ID: 20085520
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
ABSORPTION SPECTRA
AMORPHOUS STATE
CHEMICAL BONDS
CHEMICAL VAPOR DEPOSITION
CRYSTAL STRUCTURE
HYDROGEN ADDITIONS
PRECURSOR
SILICON
TRANSISTORS