PLATE-SHAPED SUBSTRATE FOR FORMING SEMICONDUCTOR ELEMENT, ITS MANUFACTURING METHOD, AND SEMICONDUCTOR ELEMENT USING IT

摘要

PROBLEM TO BE SOLVED: To solve the problem that the leakage current of a nitride-based compound semiconductor element having a multilayered buffer region becomes larger. SOLUTION: The buffer region 3 constituted by repeatedly arranging first AlN layers L1, second GaN layers L2, and third AlGaN layers L3 is formed on a silicon substrate 2. The rate of Al in the third AlGaN layers L3 is adjusted to zero or to a value between the rates of Al in the second and first layers L2 and L1. When the rate of Al in the third layers L3 is low, the occurrence of a two-dimensional electronic gas is suppressed. Then a nitride-based compound semiconductor region 4 for HEMT element is formed on the buffer region 3. Since the occurrence of the two-dimensional electronic gas in the buffer region 3 is suppressed, the buffer region 3 becomes higher in resistance and the leakage current of a HEMT element is suppressed. COPYRIGHT: (C)2005,JPO&NCIPI