| 摘要 |
PROBLEM TO BE SOLVED: To provide an HEMT device which has higher PAE than an HEMT device obtained by conventional technology has as to output electric power of previously selected level and to provide, specially, an HEMT device with improved efficiency which gives high electron mobility, high sheet carrier concentration, and a high electron speed in the channel of the HEMT device. SOLUTION: The Schottky barrier 30 varies in the percentage of aluminum slantingly so as to provide an HEMT device 32 having the efficiency and electric power improved. This Schottky barrier 30 has a lower layer formed of a 1st material having aluminum with a 1st percentage. An upper layer is arranged on the lower layer and formed of a 2nd material and part of it has aluminum with a 2nd percentage exceeding the 1st percentage. A gate of the HEMT device 32 is positioned on a part 59 of the Schottky barrier 30 which includes the aluminum with the 2nd percentage.
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