Crystal formation method

Claim 1

A gas phase method for forming II-VI group crystals or III-V group crystals in a crystal formation treatment space, comprising: forming a substrate with a non-nucleation surface (S NDS ) and an adjacent nucleation surface (S NDL ), said nucleation surface (S NDL ) being comprised of an amorphous material having a sufficiently small area of 16 μm 2 or less so as to form only a single nucleus from which a single-crystal is grown, and having a larger nucleation density than said non-nucleation surface (S NDS ), wherein said nucleation surface (S NDL ) is formed by ion implantation and the amount of the ions implanted is at least 1×10 15 /cm 3 ; heating said substrate up to a substrate temperature within a range of 200° C. to 950° C.; alternately feeding at least a first starting gas and a second starting gas into said crystal formation treatment space thereby forming said single nucleus and growing a single-crystal from said single nucleus, wherein the pressure during feeding of the starting gases is within a range of 10 -1 Torr to 10 Torr, and wherein the time for feeding the starting gases is within a range of 5 sec. to 1 min.; and during said alternate feeding step, after the feeding of one of the starting gases is terminated and before commencing the feeding of the other starting gas, evacuating said crystal formation treatment space to a pressure within a range of 10 -2 torr to 10 -5 Torr, wherein the time for evacuating the starting gases is within a range of 20 sec. to 3 min.