Patent ID: 6530991
Filing Date: 2003-03-11
Classification: C30B,H01L

Abstract:
A method for the formation of a semiconductor layer in which a GaN layer or an AlGaN layer is formed on an SiC substrate or an Al2O3 substrate by means of MOCVD (Metalorganic Chemical Vapor Deposition) equipment comprising:a first step for either supplying trimethylgallium (TMG) or triethylgallium (TEG) and ammonia (NH3) onto a surface of the SiC substrate or the Al2O3 substrate to form a GaN layer as a buffer layer, or supplying trimethylgallium (TMG) or triethylgallium (TEG) and trimethylaluminum (TMA) or triethylaluminum (TEA) and ammonia (NH3) thereon to form an AlGaN layer as a buffer layer; a second step for supplying Si being an n-type impurity material used in a GaN layer or an AlGaN layer on a surface of the GaN layer or the AlGaN layer being said buffer layer formed in said first step by means of silane (SiH4), disilane (Si2H6), or tetraethylsilane (TESi) in one monolayer or less; and a third step for either supplying trimethylgallium (TMG) or triethylgallium (TEG) and ammonia (NH3) on a surface of the GaN layer or the AlGaN layer being said buffer layer to which has been supplied said silane (SiH4), disilane (Si2H6), or tetraethylsilane (TESi) in said second step to form a GaN layer in a thickness of 1 nm or thicker, or supplying trimethylgallium (TMG) or triethylgallium (TEG) and trimethylaluminum (TMA) or triethylaluminum (TEA) and ammonia (NH3) to form a AlGaN layer in a thickness of 1 nm or thicker.