Visualization and control of particulate contamination phenomena in a plasma enhanced CVD reactor

Dust particle generation in a plasma enhanced CVD (PECVD) process and substrate contamination with the generated dust were studied. By using a laser light scattering technique, the spatial distribution of dust particles suspended in a PECVD reactor was visualized during the fabrication of silicon dioxide thin films. The dust particle size and film morphology were also measured with a laser particle counter and a scanning electron microscope. It was found that the operating conditions of the reactor influenced strongly the properties and transport of dust particles and thus substrate contamination. The effect of the modulation of the plasma input power was also investigated. A new modulation method showed a good performance in terms of both dust suppression and film growth rate.