Investigation of the gas-phase deposition of material layers in plasma-vacuum systems for MEMS production processes

This paper presents the results of gas-phase deposition of silicon epitaxial layers studies obtained under real production conditions. The research is based on innovative techniques that have expanded the physical understanding of the process, which has improved the adequacy of the final results. Based on the developed physical modeling methodology, a study of the silicon epitaxial layers deposition process was carried out. The results were processed in a generalized form and could be represented by simple criterion relations. Based on the studies the area of the technological process with maximum possible homogeneity of silicon epitaxial layers deposition parameters was determined. It was shown that the silicon epitaxial layers deposition rate is determined by the interaction between the outgoing flow (from the nozzle) and reverse flow (at the moment when the wafer is between the nozzles). The use of the technique based on the autodopping effect showed that the distribution of the dopant impurity (from the local source) in the deposition zone is inhomogeneous and a significant part of the impurity is transferred in the direction of the jet flow. The plasma chemical deposition process of SiHxNy has been studied. As a defining parameter of the plasma chemical deposition process, the number ReL characterizing the gas dynamics of the process is chosen. Studies were performed at pressures in the reaction chamber of 100, 50, and 10 Pa, which corresponds to values ReL =1.2, 0.8, and 0.4. It is shown that greater uniformity of the deposited layer occurs at higher pressures.