METHOD FOR MANUFACTURING SEMICONDUCTOR SUBSTRATE, AND SEMICONDUCTOR DEVICE

• Main Authors: NAKADA TAKESHI, KOUCHI TAKESHI, YUI KEIICHI, MAKABE ISAO
• Format: Patent
• Language: English; Japanese
• Published: 22.10.2015
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PROBLEM TO BE SOLVED: To provide: a method for manufacturing a semiconductor substrate which enables the improvement of a GaN layer in crystal quality; and a semiconductor device arranged by use of the semiconductor substrate.SOLUTION: A method for manufacturing a semiconductor substrate 1 comprises the steps of: growing an AlN layer 3 on a substrate 2; growing an AlGaN layer 4, of which the content of Al is 3.5-9%, on a surface 3a of the AlN layer 3 with Group III gas and Group V gas; growing a GaN layer 5 having a thickness of 250-1400 nm on a surface 4a of the AlGaN layer 4 with Group III gas and Group V gas; and growing an electron-supply layer 6 on the GaN layer 5. The supply of Group III gas is suspended for a length of time included in a range of 80-220 seconds after the growth of the AlGaN layer 4, but before the growth of the GaN layer 5. 【課題】ＧａＮ層の結晶品質を改善できる半導体基板の製造方法及び当該半導体基板を用いた半導体装置を提供する。【解決手段】半導体基板１の製造方法は、基板２上にＡｌＮ層３を成長する工程と、ＡｌＮ層３の表面３ａ上に、ＩＩＩ族ガス及びＶ族ガスを用いて、Ａｌの含有量が３．５％以上９％以下であるＡｌＧａＮ層４を成長する工程と、ＡｌＧａＮ層４の表面４ａ上に、ＩＩＩ族ガス及びＶ族ガスを用いて２５０ｎｍ以上１４００ｎｍ以下の膜厚を有するＧａＮ層５を成長する工程と、ＧａＮ層５上に電子供給層６を成長する工程と、を備える。ＡｌＧａＮ層４の成長後であってＧａＮ層５を成長する前に、８０秒以上２２０秒以下の範囲に含まれる時間の間、ＩＩＩ族ガスの供給を中断する。【選択図】図３