| 摘要 |
PURPOSE:To obtain a compd. semiconductor epitaxy wafer with less surface faults and having excellent flatness by using hydrogen chloride as the etching gas, and specifying the partial pressure and temp. of the hydrogen chloride and the temp. of a GaAs substrate at the time of carrying out molecular beam crystal growth. CONSTITUTION:A molecular beam crystal growth chamber is evacuated to ultrahigh vacuum, a molecular beam is injected onto the GaAs substrate set to a manipulator and held at an appropriate temp. from a molecular beam cell contg. a source substance consisting of the element constituting a desired compd. semiconductor, and epitaxy is carried out as follows: (1) A gas etching chamber is provided in a molecular beam crystal growth device to obtain an epitaxy layer without any surface fault by molecular beam epitaxy. (2) A GaAs wafer if heated to 400-500 deg.C in the gas etching chamber. (3) the gaseous HCl kept at from room temp. the 900 deg.C is introduced into the gas etching chamber so that the partial pressure of the gas is controlled to 10<-3>-10<-5>Torr, and projected on the GaAs wafer. The is etched by the gas, the wafer is transferred to the molecular beam crystal growth chamber without being exposed to the atmosphere, the molecular beam epitaxy is carried out.
|
