SEMICONDUCTOR HETEROSTRUCTURE AND METHOD FOR FORMING A SEMICONDUCTOR HETEROSTRUCTURE

摘要

The invention relates to a method for forming a semiconductor heterostructure comprising providing a substrate with a first in-plane lattice parameter a1, providing a buffer layer with a second in-plane lattice parameter a2 and providing a top layer over the buffer layer. In order to improve the surface roughness of the semiconductor heterostructure, an additional layer is provided in between the buffer layer and the top layer, wherein said additional layer has a third in-plane lattice parameter a3 which is in between the first and second lattice parameter.