| 摘要 |
<p>PURPOSE:To uniformly reduce the density of threading dislocations by inserting, into a semiconductor heteroepitaxially grown film, a single crystal thin-film whose lattice constants are largely different from those of the grown film and whose modulus of rigidity is larger than that of the grown film, dividing those films, and subjecting those films to a heat treatment. CONSTITUTION:After a silicon substrate 5 is subjected to proper chemical cleaning and then placed in a molecular beam epitaxy(MBE) device, it is heated at about 900 deg.C for 15 minutes and an oxide film on the substrate surface is removed. Then, an AlAs buffer film 8 of a 10-atom thickness is grown at 400 deg.C. Then, a GaAs film 6 of a l-mum thickness is grown at 600 deg.C at a growth rate of about 1mum/hour. Next, a Ge thin-film 7 of a 200-nm thickness is grown at 400 deg.C, and a GaAs film 6 of a 1-mum thickness is grown again. Then, cutting and a heat treatment are performed. As a result, it is confirmed that the density of dislocations is less than 10<4>/cm<2> in any divided region.</p> |
