Patent ID: 6439514
Filing Date: 2002-08-27
Classification: H01L

Abstract:
A semiconductor device comprising:a first silicon layer; a first insulation film disposed on the first silicon layer; a second silicon layer disposed on the first insulation film; a plurality of first semiconductor elements provided in the second silicon layer to have a first electric potential; a plurality of second semiconductor elements provided in the second silicon layer to have a second electric potential smaller than the first electric potential; a plurality of first trenches provided in the second silicon layer to reach the first insulation film and respectively surrounding the plurality of first semiconductor elements; a plurality of second trenches provided in the second silicon layer to reach the first insulation film and respectively surrounding the plurality of second semiconductor elements; a third trench provided in the second silicon layer to reach the first insulation film and surrounding the plurality of first trenches; and a fourth trench provided in the second silicon layer to reach the first insulation film and surrounding the plurality of second trenches, wherein a portion of the second silicon layer between the plurality of first trenches and the third trench has a third electric potential larger than the second electric potential.