Patent ID: 9018637
Filing Date: 2015-04-28
Classification: H01L

Abstract:
1. A transistor comprising: a structural body including a first semiconductor region of a first conductivity type, a second semiconductor region of a second conductivity type provided on the first semiconductor region, and a third semiconductor region of the first conductivity type provided on the second semiconductor region, the structural body including a compound semiconductor having a first element and a second element; an insulating film provided on the second semiconductor region; a control electrode provided on the insulating film; a first electrode electrically continuous with the third semiconductor region; and a second electrode electrically continuous with the first semiconductor region, the structural body having a first region provided above a lower end of the second semiconductor region and a second region other than the first region, the first region being a region formed by making a ratio of concentration of source gas of the second element to concentration of source gas of the first element larger than 1.0, and impurity concentration of the first conductivity type in the first region being higher than impurity concentration of the first conductivity type in the second region, wherein the second region is a region formed by setting the ratio to 1.0, and the first region is a region formed by setting the ratio to larger than 1.0 and 2.0 or less.