一、引言由于外延单晶薄膜制备的成功,给器件制造提供了新的有用工艺技术。近年来用这一技术已制造出一些电子器件,他们具有独特的优越性能,例如饱和压降小,开关时间短等。这是外延生长单晶对器件的促进。但是由于器件的需要,对外延生长单晶薄膜又提出新的要求,例如不在锗上外延锗、硅上外延硅,而是在GaAs上外延锗,制成异质结,这样也促进了外延更广 I. INTRODUCTION Due to the success of the epitaxial single crystal film preparation, new useful process technologies are provided for device manufacturing. In recent years, some electronic devices have been manufactured using this technology. They have unique superior properties such as small saturation voltage drop and short switching time. This is the epitaxial growth of single crystal device to promote. However, due to the requirement of the device, new requirements are also put forward for the epitaxial growth of the single crystal thin film. For example, germanium is not epitaxially deposited on the germanium and epitaxial silicon is epitaxially grown on the silicon, but germanium is epitaxially grown on the GaAs to form a heterojunction. wide