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Misfit Dislocation Superlattice Production

IP.com Disclosure Number: IPCOM000062381D
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09

Publishing Venue

IBM

Related People

Authors:
Kaplan, SB Kuan, TS Van Vechten, JA Woodall, JM [+details]

Abstract

A semiconductor superlattice is produced by using lattice misfit dislocations in epitaxial layers in order to form a mask. Misfits have been formed, for example, in GaInAs/GaAs MBE (molecular beam epitaxy) layers with an average spacing as small as 40 nm. In order to form a periodic array of such dislocations, a dislocation-free single-crystal substrate is employed so that there are no pinning sites for the misfit dislocations. A second material with the same crystal structure but a different lattice constant, i.e., with a lattice mismatch, is then grown epitaxially on top of the first to a thickness great enough that the elastic stress is relieved by the generation of misfit dislocations. The array of misfit dislocations will be square and regularly spaced in both directions after moderate annealing.