SEMICONDUCTOR DEVICE AND ITS MANUFACTURE

摘要

PURPOSE:To improve the element isolation breakdown-strength of an N-channel transistor region. CONSTITUTION:A LOCOS oxide film 2 for isolating an element region from another element region is provided on the main surface of a semiconductor substrate 1. A channel cut layer 7a formed of P-type impurity is provided under the element regions. A P<+>-impurity region 34 higher in concentration than the P-type impurity in the channel cut layer 7a is formed on the main surface of the semiconductor substrate 1 and directly under the bird's beak part of the LOCOS oxide film 2.