Method for forming crystal and crystal article obtained by said method

A method for forming a crystal, which comprises forming, on a substrate having a small deposition surface (S.sub.NDS) will small nucleation density at a small area for a crystal growth from only a single nucleus at a desired position of said deposition surface (S.sub.NDS) a deposition surface (S.sub.NDL) having greater nucleation density (ND.sub.L) than the nucleation density (ND.sub.S) of said deposition surface (S.sub.NDS) by addition of a material (M.sub.L) for forming said deposition surface (S.sub.NDL) which is different from the material (M.sub.S) forming said deposition surface (S.sub.NDS), and then applying a crystal forming treatment on said substrate to form a single crystal nucleus on said deposition surface (S.sub.NDL), thereby growing a single crystal from said single nucleus.

A method for forming a crystal which forms a crystal by utilizing the difference in nucleation density between the crystal forming materials according to the kinds of the materials for forming the crystal forming surface, which comprises forming a nucleation surface (S.sub.NDL) having a sufficiently small area so that only a single nucleus may grow with a material having sufficiently greater nucleation density than the material forming said crystal forming surface, forming only a single nucleus on said nucleation surface (S.sub.NDL) and growing a single crystal from said single nucleus, thereby forming a crystal.

A method for forming a crystal by forming selectively a single crystal layer by utilizing the difference in nucleation density between the crystal forming materials according to the kinds of the materials for forming crystal forming surfaces, preparing said crystal forming surface formed of an amorphous material, providing nucleation surfaces (S.sub.NDL) on said crystal forming surface with a material having sufficiently greater nucleation density than the material forming the crystal forming surface so as to have a sufficiently small area to form only a single nucleus, and with a distance of the required size of said single crystal layer or more, and then forming only a single nucleus on said nucleation surface (S.sub.NDL) to grow a single crystal from said single nucleus, thereby forming selectively a single crystal layer.

A method for forming a crystal article on a substrate, said crystal article having a crystal portion formed from a plurality of single crystals and said substrate having a plurality of nucleation surfaces and a second surface comprising:

• (a) vapor depositing on each of said plurality of nucleation surfaces a single nucleus suitable for forming a single crystal, each of said nucleation surfaces (i) being of metal or a semiconductor material, (ii) having an area of 10 .mu.m or less in maximum diameter, (iii) being formed of a material different from the material constituting said second surface and (iv) having a nucleation density sufficiently larger than the nucleation density of said second surfaces to selectively form said single nucleus, said nucleation surfaces being spaced apart from each other by a distance;
• and
• (b) growing by vapor deposition each said single crystal from each said single nucleus on each said nucleation surface such that there is one single crystal grown for each said nucleation surface, each said single crystal being formed of a material different from said metal or the material constituting the semiconductor nucleation surface and being overgrown onto said second surface.

A method for forming a crystal article on a substrate, said crystal article having a crystal portion formed from a plurality of single crystals and said substrate having a plurality of nucleation surfaces and a second surface comprising:

• (a) vapor depositing on each of said plurality of nucleation surfaces a single nucleus for forming a single crystal, each of said nucleation surfaces (i) being modified by ion-implantation from the composition of said second surface, (ii) having an area of 10 .mu.m or less in maximum diameter and (iii) a nucleation density sufficiently larger than the nucleation density of said second surface to selectively form said single nucleus, said nucleation surfaces being spaced apart from each other by a distance;
• and
• (b) growing by vapor deposition each said single crystal from each said single nucleus on each said nucleation surface such that there is one single crystal grown for each said nucleation surface, each said single crystal being formed of a material different from the material constituting each said nucleation surface and each said single crystal being overgrown onto said second surface.