Plasma-enhanced Chemical Vapor Deposition And Al-induced Crystallization Of Si_1-xGe_x Thin Film

Polycrystalline silicon germanium (Poly-SiGe) thin film is widely used in microelectronics manufacturing, photoelectric integration and thin-film solar cells, and other fields. Except in some aspects it is close to the performance of crystalline silicon germanium(c-SiGe), more important, it has lower manufacturing costs. Particularly with the development of large size of electronic devices, cheap substrates, such as glass substrate, are widely used, that making all kinds of low-temperature deposition technology important. In this paper we used plasma-enhanced chemical vapor deposition (PECVD) and Al-induced crystallization to prepare Poly-SiGe thin film, carried out as follows:(1) We introduced the excellent performance of Poly-SiGe thin film and its application in the device. Then we commented the action of plasma in PECVD of SiGe thin film, analyzed the growth mechanism and optimized the deposition process parameters of SiGe thin film. PECVD makes the film deposition generally amorphous. It takes the latter part of heat treatment to better crystallization.(2) We have investigated the Al-induced a-SiGe thin film crystallization and confirmed that: As Al-induced, crystallization temperature is greatly reduced. Annealing temperature, annealing time and Ge content also impact on the film. With the increase of annealing temperature, annealing time and Ge content, crystallization process advances and grain size increases.(3) We also have investigated Al-induced germanium film crystallization. AlGe forms a simple binary alloy system and aluminum plays a pioneer role in the process of crystallization. Film crystallization improves when the annealing temperature and annealing time increase and show good selectivity growth characteristics.