DISTORTION RELAXED GERMANIUM FILM, PROCESS FOR PRODUCING THE SAME, AND MULTILAYERED FILM STRUCTURE

摘要

A Ge (germanium) dislocation control layer (4), which is formed of a plurality of clusters (5) of Ge crystal grains and has a defect nucleus capable of functioning as a source for edge dislocation (4) at a part of collision between the hat clusters (5), is formed by epitaxial growth on an Si (silicon) substrate (2). Thereafter, an amorphous Ge film (7) is formed by epitaxial growth in a low-temperature region, in which the hat clusters (5) are not broken, to form an amorphous Ge film (7) which is then crystallized. The amorphous Ge film (7) is further heat treated to introduce edge dislocation (4) using the defect nucleus as the edge dislocation source and thus to form a distortion relaxed Ge film (3), which has been distortion relaxed by the edge dislocation (4), on the Si substrate (2). In the distortion relaxed Ge film (3), in a range of 1 µm square in the interface of the distortion relaxed Ge film (3) and the Si substrate (2), the total length of a dislocation line in 60º dislocation is brought to not more than 10 µm. Thus, irregular 60º dislocation can be reduced to reduce mosaicity.