| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve the quality of an epitaxial growth nitride-based compound semiconductor by using a sapphire substrate slightly inclined to C axis, and thereby to provide a very smooth front face state. <P>SOLUTION: A substrate uses a mirror-polished sapphire (0001) inclined by 0.05 to 0.2 degrees from a <0001> orientation. By maintaining the inclination angle within a range from 0.05 to 0.2 degrees, a step density on the sapphire substrate is optimally controlled to keep a very flat front face and reduce the defect density, thereby obtaining a nitride-based compound semiconductor film with improved electrical and optical characteristics. The nitride-based compound semiconductor referred to in this invention means a compound expressed by the following general equation: In<SB>X</SB>Ga<SB>Y</SB>Al<SB>Z</SB>N (x+y+z=1, 0≤x≤1, 0≤y≤1, and 0≤z≤1). <P>COPYRIGHT: (C)2007,JPO&INPIT |
