| 摘要 |
PURPOSE:To obtain a high withstand voltage SCR having a stable leakage current inhibiting characteristics by forming the same conducting type high density semiconductor layer as respective main surfaces thereof on the portion formed with current collecting electrodes. CONSTITUTION:A p-type base 3 and a p-type emitter 1 are exposed on both peripheral regions 300 of the SCR substrate 10. Aluminum is annularly evaporated on the peripheral regions 300, annular current collecting W electrodes 8, 9 are coated thereon, and heated to be bonded at a temperature higher than the melting point of aluminum. At this time p<+>-type layers 40 are formed on the bonded surfaces of the electrodes 8 and 9 respectively. Then, Si rubber material 20 is coated on both the electrodes 8 and 9 to protect the side surfaces of the substrate. According to this configuration the number of the lines of electric force collected at the base 3 is reduced due to the installation of the electrodes 8 to alleviate the surface electric field intensity on the end side surfaces 103 of the substrate 10. Since there is the layers 40 on the regions 300 directly under the electrodes 8, which layers 40 are not depleted nor inverted, the channel growth is inhibited by the layers 40 and does not reach the cathode 6. Accordingly, it can obtain low leakage current and stable leakage current inhibiting characteristics without increasing the leakage current. |
