| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device having high breakdown voltage horizontal MISFET which can be prevented from decreasing in breakdown voltage over changes due to time passage, under the high voltage and high moisture conditions in which it is used and therefore is stable. SOLUTION: The semiconductor device is provided with the high breakdown voltage horizontal MISFET whose breakdown drain voltage is 700 V. In the semiconductor device, Mc and Tox are set to be not lower than lower limit values Mcmin and Tcmin which satisfy the inequalities Tcmin <=7 and Mcmin >=35-5 Tcmin , where Mc [μm] is an overhanging length of a field plate FP1 from the end on the source side of a thermal oxidation film 8 and Tox [μm] is a thickness of all the insulation films (8 and 10), immediately below the end of the overhanging part of the field plate FP1. Thus, even if the electric charge accumulation grows in an interface of a mold resin 15 in actual use, the electric field strengths at points B and C are always lower than that at a point A, suppressing the decline in both breakdown voltage and on-state current over time and thereby realizing a breakdown voltage of 700 V. |
