| 摘要 |
PURPOSE:To improve a switching characteristic and OFF characteristic making the distribution of a carrier life time uniform by a method wherein an Au a life time killer is attached on one main surface of a semiconductor substrate having a PN junction and then applied a heat treatment at 700-1,000 deg.C. CONSTITUTION:A Ga is diffused and then a P type base layer 13 and P type anode layer 12 provided with gate electrodes are formed on both sides of the face and the reverse of an Si substrate 11 which will be an N type base layer, a thin phosphor layer in high concentration is attached to the layer 13 and driven-in at 1,200 deg.C to obtain an N type cathode layer 14. In the following, the Au layer 15 is attached to the layer 12 on the back side and a PSG film 26 is formed on the layer 14 on the opposite side by low temperature CVD method and heat treatment is applied to those to diffuse the Au in the layer 15. In such a manner, a gettering takes place in P in the PSG film 26 and accordingly, the Au in the substrate 11 is equally distributed. Thereafter, the film 26 is removed and electrodes are fixed in the respective regions to make the thyristor elements. |
