| abstract |
The characteristics of a semiconductor device are improved. A semiconductor device of the present application is connected to an upper electrode made of a semiconductor layer SL of a SOI substrate, a capacitive insulating film made of an insulating layer BX, a lower electrode made of a support substrate SB, and a support substrate in a region 1C. And a lower electrode lead portion (n-type high concentration impurity region NP). The SOI transistor in the region 1B is formed on the main surface of the semiconductor layer SL on the thin insulating layer BX, and the threshold voltage is adjusted by applying a voltage to the well disposed on the back side of the insulating layer BX. be able to. The film thickness of the thin insulating layer BX is 50 nm or less, more preferably, several nm or more and 30 nm or less. Therefore, the insulating layer BX functions sufficiently as a capacitor insulating film and can be used as a high-capacitance capacitor element. [Selection] Figure 1 |