| 摘要 |
<p>A semiconductor overvoltage protection device in the form of a four layer diode has first (12) and third (18) layers of a first conductivity semiconductor material, second (14) and fourth (20) layers of a second conductivity type semiconductor material and a first buried region (42) of the first conductivity type in the third layer (18) adjacent to the junction between the second (14) and third (18) layers. The buried region has a greater impurity concentration than the third layer (18). The first layer (12) is penetrated by a plurality of dots (24) of the second layer (14) extending through the first layer and the first buried region (42) lies wholly beneath the second layer (14) and is laterally offset from the dots (24) and the first layer (12).</p> |
