| 摘要 |
PURPOSE:To change the operating conditions of a semiconductor element by the voltage control through the control electrode, by providing the third electrode for control between two regions through an insulating film, and moreover providing a semiconductor region by combining a plurality of control electrodes. CONSTITUTION:Formed are a semiconductor region 1 to form a space charge at the operating state, a low-resistance region 2 to form an ohmic contact therebetween, a low-resistance region 3 to form a P-N junction or Schottky junction with the region 1 and a control electrode 5 on an insulating film 4. The avalanche breakdown voltage between the regions 2 and 3 is mostly determined by the electric field E at the portion of the region 1 close to the region 3, and when the electric field exceeds the critical value EC, avalanche breakdown takes place. The electric field at siad portion is determined by the voltage VD between the regions 2 and 3 and the voltage VG between the electrode 5 and the region 3, and when E=EG+ED>=EC, avalanche breakdown takes place. In this case, bacause the electrode 5 is closer to the region 3 that to the region 2, DELTAVD>DELTAVG is required to obtain DELTAE. In other words, if the variaton of the avalanche breakdown voltage BVD is represented by DELTABVD, DELTABVD/VG>1 is formed. Accordingly, a voltage gain can be obtained by controlling the avalanche breakdown voltage through the third electrode. |
