JPS6419712A - Growth method for thin-film by high-speed corpuscular beam - Google Patents

Abstract

PURPOSE:To grow a thin-film crystal having few surface defects at a low temperature by jointly using raw-material gas molecules and inert gas molecules having large mass and making each molecule collide against the surface of a semiconductor and a dielectric as independent supersonic molecular beams. CONSTITUTION:GaCl3 in a raw material for growing Ga reaches a substrate 12 as the supersonic molecular beams 20 of the mixed gas of GaCl3 and H2 through a supersonic molecular-beam generating chamber 18, into which a nozzle 16 and a skimmer 17 are disposed, and a differential exhaust chamber 19, using H2 as a carrier gas. AsH3 as a raw material for growing As is fed from an AsH3 bomb 21 in an H2 base. The mixed gas of Xe and H2 fed from a bomb 25 apart from these raw material gases is passed through a second nozzle 28 heated at approximately 700 deg.C in a second nozzle heater 29. The gas is then passed through a second supersonic molecular-beam generating chamber 27 and a second differential exhaust chamber 26 and applied to the substrate 12 composed of GaAs. Since the band gap energy of GaAs extends over approximately 1.4ev, the kinetic energy of GaCl3, AsH3 and Xe must be made larger than the value.