| 摘要 |
PURPOSE:To improve hot carrier withstanding voltage and drain withstanding voltage in an MOSFET, by a constitution wherein a gate electrode covers at least a low-impurity concentration region in a drain region. CONSTITUTION:A field oxide film 17 is formed on the main surface of a P<-> type silicon substrate 11, and an active region is difined. In this active region, a gate oxide film 12 and a gate electrode 13 comprising polycrystalline silicon are formed. On the main surface of the silicon substrate, source and drain regions 14 and 15 comprising high-impurity-concentration regions 14a and 15a, which have the reverse conductivity type (N-type) with respect to that of the substrate, and low-impurity concentration regions 14a and 15b are formed. The gate electrode 13 is constituted so that its length covers the approximately entire region of the low-impurity concentration regions 14b and 15b, i.e., both ends of a the gate electrode 13 reach the high-impurity concentration regions 14a and 15a. Therefore, the effect of hot carriers in the low-impurity concentration regions is reduced, and the characteristics of an MOSFET such as the drain withstand voltage can be improved.
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