| 摘要 |
PURPOSE:To make the junction section hard to break down by a method wherein the junction depth of a field limiting on the most outside circumference is formed shallower than that of the inside field limiting to eliminate the oscillation of the break-down current wave-form caused by the elongation of the depletion layer. CONSTITUTION:The junction depth of an outside FL ring 16 is formed shallower than the inside FL rings 14, 15. Thus, when a depletion layer extends beyond the FL ring 16, the depletion layer will bend rapidly, with the curvature of the bending section on the depletion layer corresponding to the junction bending section of the FL ring being the largest. As the result, an abnormal electric field concentration appears on the junction bending section of the FL ring 16, positively producing the beak-down. Since the break-down on the junction bending section of this FL ring does not cause so much effect to make the width of the depletion layer on the center side narrower, no elongation and contraction due to the break-down appear on the depletion layer on the center side. |
