Laser crystallization and structural characterization of hydrogenated amorphous silicon thin films

Journal Article · Tue Jun 01 04:00:00 EDT 1999 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.370607· OSTI ID:348234

Toet, D; Smith, P M; Sigmon, T W ^[1]; Takehara, T; Tsai, C C; Harshbarger, W R ^[2]; Thompson, M O ^[3]

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1. Lawrence Livermore National Laboratory, 7000 East Avenue, L-271, Livermore, California 94550 (United States)
2. Applied Komatsu Technology, 3101 Scott Boulevard, M/S 9155, Santa Clara, California 95054 (United States)
3. Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853 (United States)

The influence of hydrogen and film thickness on the excimer laser-induced crystallization of plasma-enhanced chemical-vapor deposition-grown hydrogenated amorphous silicon thin films has been studied. Films with hydrogen concentrations varying from 1 to 10 at.{percent} have been crystallized using short pulses from a XeCl excimer laser, at fluences sufficient to induce melting throughout the thickness of the films. Dehydrogenation prior to laser exposure was necessary only for films having initial hydrogen concentrations larger than 5 at.{percent}. The structural properties of the laser-crystallized materials were studied by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The AFM measurements revealed that films requiring no dehydrogenation are smoother after laser crystallization than those requiring laser dehydrogenation, and that the roughness of these films increases as a function of film thickness, although it could be reduced by multiple laser exposure. Smoother films (root-mean-square roughness {approximately}4.1 nm) were obtained by melting only the near-surface region of the film after the initial full melt exposure. TEM revealed that the laser-crystallized films consist of grains with sizes that are comparable to the film thickness. {copyright} {ital 1999 American Institute of Physics.}

• OSTI ID: 348234
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11 Vol. 85; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMORPHOUS STATE
CRYSTALLIZATION
GRAIN SIZE
HYDROGEN
HYDROGENATION
LASER-RADIATION HEATING
ROUGHNESS
SILICON
STRUCTURAL CHEMICAL ANALYSIS
THICKNESS
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY