| 摘要 |
1457585 Semiconductor superlattice crystals INTERNATIONAL BUSINESS MACHINES CORP 19 March 1974 [16 April 1973] 12057/ 74 Heading B1S A method of growing coherent, substantially dislocation free semiconductor superlattice crystals, e.g. compositions of group IV IV, III III V and III V V elements, comprises growing in alternative layers a first and second crystalline material on a suitable substrate, the layers being grown to less than a maximum critical thickness to give coherent interfaces and to generate no misfit dislocation, the critical thickness being defined by the expression where and wherein G is the sheer modulus of the layers, b is Poisson's ratio, fI is the misfit between the layers, # is the angle between the slip direction and that direction in the film plane which is perpendicular to the line of intersection of the slip plane and the specimen surface, 1 is the Burger's vector, and h is the thickness of the layers, and the layers having an average lattice parameter equal to the lattice parameter of the substrate. The preferred group III elements are In, Ga, Al and B and the group V elements are N, P, As and Sb. The growth of alternate layers of GaAo and GaAoP is exemplified using rapan phase deposition and growing the layers to a thickness less than 350Š with a lattice parameter of approximately 5.6A. The multilayers may contain, for example, 60 layers with layer thicknesses of approximately 300Š. |
