Methods for growing defect-free heteroepitaxial layers

A method for growing a defect-free heteroepitaxial layer on a substrate comprising the steps of:

• a) providing a substrate formed from a first material;
• b) forming a plurality of separated nucleation sites on a surface of said substrate by the steps of:
• 1) forming a plurality of small metal clusters on said substrate;
• 2) forming an oxide layer on portions of said substrate surface that are not covered by said metal clusters;
• and
• 3) etching said metal clusters from said substrate, thereby forming exposed portions of said substrate surface that act as said nucleation sites;
• c) growing a layer of a second material on each of said nucleation sites to form a plurality of nucleation islands on said substrate, said second material being selected to be lattice mismatched with said first material;
• and
• d) continuing the growth of said layer on each of said nucleation sites to increase the size of said islands vertically and laterally until said islands coalesce, thereby forming a thin film heteroepitaxial layer formed from said second material on said substrate.

A method for growing a defect-free heteroepitaxial layer on a substrate comprising the steps of:

• a) providing a substrate formed from Si;
• b) forming a plurality of separated nucleation sites on a surface of said substrate by the steps of:
• 1) forming a plurality of GaAs islands on said substrate surface by growing a thin layer of GaAs on said substrate;
• 2) oxidizing said substrate surface and said GaAs islands, there-by forming GaAs native oxide over said GaAs islands, and SiO2 over portions of said substrate surface not covered by said GaAs islands;
• and
• 3) heating said substrate to desorb said GaAs native oxide without desorbing said SiO2, thereby exposing said GaAs islands which act as said nucleation sites;
• c) growing a layer of a second material on each of said nucleation sites to form a plurality of nucleation islands on said substrate, said second material being selected to be lattice mismatched with said first material;
• and
• d) continuing the growth of said layer on each of said nucleation sites to increase the size of said islands vertically and laterally until said islands coalesce, thereby forming a thin film heteroepitaxial layer formed from said second material on said substrate.