SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device having a normally-off HEMT.SOLUTION: A semiconductor device includes a gate insulation film 4 having a layered structure of a first insulation film 4a and a second insulation film 4b, in which the first insulation film 4a is composed of an insulation film containing an element which has a stronger binding power with oxygen than the second insulation film 4b thereby to increase a total charge quantity. In particular, it becomes possible to perform a supplementing process of oxygen (O) in an aluminum oxide film by performing oxygen annealing thereby to increase a total charge quantity. As a result, a negative fixed charge density in the gate insulation film 4 near a GaN substrate interface can be made to be 2.5×10cmand over thereby to successfully achieve a normally-off element.SELECTED DRAWING: Figure 1