| 摘要 |
Realized is a compound semiconductor device which has a high withstand voltage and reliability by realizing a normaly off by obtaining a voltage of a large threshold value without a relatively simple composition, a withstand voltage deterioration and an operation instability. The compound semiconductor device includes a firs layer (3), a second layer (4) which is formed on the first layer and has a band gap which is greater than the first layer (3), a third layer (5a) which is formed on the second layer and has a p type conductivity, a gate electrode (11) which is formed by forming the second layer on the third layer (5a), a forth layer (6) which touches the third layer (5a) and has a band gap which is greater than the forth layer (6), and a fifth layer (7) which touches the third layer (5a) on the fourth layer (6) and has a band gap which is lower than the fourth layer (6). |
