Heteroepitaxial growth of lattice mismatch and thermal expansion under

摘要

(57) Method of forming an epitaxial layer of low defect density SUMMARY lattice mismatch substrates, involves limiting the dislocation through interaction with the stress field in the epitaxial layer and dislocations. This method can be applied to heteroepitaxial material systems with any degree of lattice mismatch of any. And selecting a top substrate layer and the epitaxial layer is desirable for the epitaxial growth, a step of determining the thermal expansion coefficient and lattice constant of the top substrate layer and the final epitaxial layer, the method, the lattice mismatch between the top substrate layer and the epitaxial layer preferable epitaxial layer to have a thermal mismatch zero or negative (positive) to the composite substrate if is positive (negative), to form a composite substrate by joining the board layer under the upper substrate layer a step, and the lattice epitaxial layer matches, and a step of selecting the buffer layer to be deposited in front of the desired epitaxial layer. The buffer layer is selected, when a positive (negative), the lattice mismatch should have a thermal mismatch positive (negative) with respect to the entire substrate. Each lattice mismatch or thermal mismatch positive (negative) is defined as having a larger lattice constant or coefficient of thermal expansion (smaller) than the substrate.