J. Phys. IV France 09 (1999) Pr8-1107-Pr8-1114
Correlations between stress and microstructure into LPCVD silicon filmsP. Temple-Boyer1, B. de Mauduit2, B. Caussat3 and J.P. Couderc3
1 LAAS-CNRS, 7 avenue du Colonel Roche, 31077 Toulouse cedex, France
2 CEMES-CNRS, 29 avenue Jeanne Marvig, 31055 Toulouse cedex, France
3 ENSIGC, 18 chemin de la Loge, 31078 Toulouse cedex, France
Silicon films have been deposited by low pressure chemical vapour deposition (LPCVD) from silane SiH4 at temperatures and pressures varying respectively from 520°C to 750°C and from 100 mTorr to 300 mTorr. Films residual stresses are studied as a function of deposition parameters (temperature and total pressure). Major stress variations (from compressive to tensile values) are explained through the cumulated influences of the deposition and crystallisation phenomena, evidencing correlations with silicon microstructure (amorphous, semicrystalline, mixed crystalline or polycrystalline) characterised by transmission electron microscopy (TEM) . Finally, residual stress and silicon microstructure are directly related to the ratio between deposition and crystallisation rates, enabling the development of laws for their modelling into silicon films deposited by LPCVD.
© EDP Sciences 1999