국가 : US
등록번호(Patent No.)/ 일자 06169297 (2001.01.02)
출원번호(Appl.No.)/ 일자 19980213735 (1998.12.17)
출원인(Assignee) Kwangju Institute of Science and Technology
A metal thin film with an ohmic contact for light emit diodes and a method of producing such a film are disclosed. The metal thin film has a p-type gallium nitride (GaN) semiconductor layer. Nickel (Ni), platinum (Pt) and gold (Au) layers are deposited on the GaN semiconductor layer in a way such that the gold layer forms a top layer, with either one of the platinum and nickel layers being selectively used as an inter-diffusion barrier between metal layers. The inter-diffusion barrier may be formed by depositing platinum between the nickel and gold layers, thus forming an Ni/Pt/Au metal thin film, or formed by depositing nickel between the platinum and gold layers, thus forming an Pt/Ni/Au metal thin film. In the method, a GaN semiconductor is washed so as to be free from carbide and oxide layers. The Ni, Pt and Au layers are formed on the GaN semiconductor layer through a vacuum deposition process at 5.times.10.sup.-5 -2.times.10.sup.-1 torr. The GaN semiconductor, having the metal thin film, is heat treated for 30 seconds-3 hours and at 250-1,000.degree. C., and under nitrogen or argon ambient.
A metal thin film with an ohmic contact for light emit diodes, comprising:
a p-type gallium nitride (GaN) semiconductor layer;
a nickel (Ni) layer deposited on said p-type gallium nitride (GaN) semiconductor layer;
a platinum (Pt) layer deposited on said nickel (Ni) layer; and
a gold (Au) layer deposited on said platinum (Pt) layer, thus forming an Ni/Pt/Au metal thin film;
said platinum (Pt) layer being used as an interdiffusion barrier between said gold layer and said nickel layer.