MEASUREMENT OF ABSOLUTE DENSITIES AND SPATIAL DISTRIBUTIONS OF SI AND SIH IN AN RF-DISCHARGE SILANE PLASMA FOR THE CHEMICAL VAPOR-DEPOSITION OF A-SI-H FILMS

Laser-induced fluorescence (LIF) spectroscopy has been applied to the detection of Si and SiH radicals in a silane plasma used in the chemical vapor deposition of a-Si:H films. Simple methods have been established for the calibration of the absolute densities. From the measured spatial distributions of those densities, the flux onto the substrate surface has been deduced. Based on these measurements, the contribution of Si and SiH radicals to the film growth is discussed in relation with the deposition rate, and it is concluded that, in quantity, these radicals do not contribute significantly to the deposition but may affect the quality of the films.