Structure and crystal growth of atmospheric and low-pressure chemical-vapor-deposited silicon films

• Published in: Journal of applied physics 1986-02, Vol.59 (4), p.1167-1178
• Main Authors: BISARO, R, MAGARINO, J, PROUST, N, ZELLAMA, K
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.336554

Structure and crystal growth of undoped, as-deposited, and annealed silicon films prepared by chemical vapor deposition (CVD) and low-pressure chemical vapor deposition (LPCVD) of silane have been studied with use of x-ray diffraction, Raman spectroscopy, and scanning electron microscopy (SEM). The grain size and a complete texture analysis are performed on CVD films grown at atmospheric pressure and temperature range 600≤Td≤805 °C, LPCVD films grown in the pressure range 0.1≤Pd≤2 Torr and temperature range 500≤Td≤650 °C and annealed amorphous CVD and LPCVD films near Ta=600 °C. We obtain systematically amorphous, strong 〈220〉 polycrystalline, and inhomogeneous partially crystallized films 〈111〉 or 〈311〉 oriented depending on the deposition conditions. The presence of a given texture is explained by a model which takes into account the specific free surface energies of the starting equilibrium forms and the extinction of some crystalline planes by {111} slow growing facets. The appearance of the 〈220〉 texture is explained by a gas phase nucleation of crystal occurring during deposition, whereas the observed 〈311〉 texture of LPCVD films is supposed to be due to a gas-phase nucleation mechanism occurring during the first stages of deposition followed by a solid-phase crystallization mechanism.