Method of manufacturing a wafer

In a method of manufacturing a wafer comprising a single crystalline bulk substrate of a first material having a working surface which includes thereon at least one epitaxial layer of a second material which has a lattice different from the lattice of the first material, the improvement which comprises:

• providing a rough working surface of the bulk material to provide a micro-roughened surface that is rougher than a polished surface for growth of an epitaxial layer of the second material thereon in order to obtain a reduced number of threading dislocations and an enhanced strain relaxation in the epitaxially grown material compared to that of a second material that is epitaxially grown on a polished surface.

A method of manufacturing a wafer comprising a single crystalline bulk substrate of a first material having a working surface which includes thereon at least one epitaxial layer of a second material which has a lattice different from the lattice of the first material, which method comprises:

• roughening the working surface of the bulk substrate to provide a micro-roughened surface that is rougher than a polished surface, wherein the roughening comprises the combination of (a) ion implantation in the working surface of the bulk substrate at an implantation energy between about 0.2 keV and about 5 keV and at an implantation dose that is kept below amorphization of the surface of the bulk substrate and is between about 5×1012 cm−2 and about 5×1014 cm−2, and (b) etching or oxidizing of the working surface;
• and
• growing an epitaxial layer of the second material on the roughened surface with a reduced number of threading dislocations and an enhanced strain relaxation compared to that of a second material that is epitaxially grown on a polished surface.