| 摘要 |
<p>PURPOSE:To avoid the deterioration in withstand voltage and operational efficiency due to laser scribing by a method wherein mesa grooves are provided with central bumps; thin glass protective films are formed on the bumps; and P-N junction exposed in the meas grooves are coated with thick glass protective films. CONSTITUTION:A P-type impurity is diffused on both sides of an N-type semiconductor wafer 1 to form a gate region 2 and an anode region 4 and then an N-type impurity is diffused to form multiple cathode regions 3 separated from one another. Later insulating films 7, 7' are formed as etching masks on both sides of the wafer in the central part between semiconductor elements to form mesa grooves 6 by etching the wafer 1. At this time, the insulating films 7' between the semiconductor elements are removed by the etching process leaving bumps 8. Next glass protective films 9 are formed in the mesa grooves 6. At this time, extremely thin glass protective films 9 are formed on the central bumps 8 and then the central bumps 8 are irradiated with laser beams for scribing the semiconductor elements to separate them into pieces.</p> |
