SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME
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Accused Products
Abstract
A semiconductor device including a drain region of a first conductivity type formed on a semiconductor substrate; an element forming region that is provided on the drain region and that has a concave portion reaching the drain region; a gate electrode disposed in the concave portion; a superjunction structure portion that is disposed in the element forming region and that is formed by alternately arranging a drift layer of the first conductivity type penetrated by the concave portion and a resurf layer of a second conductivity type being in contact with the drift layer on the semiconductor substrate; and a base region of the second conductivity type that is disposed on the superjunction structure portion so as to be in contact with the drift layer in the element forming region, that is penetrated by the concave portion, and that faces the gate electrode with the gate insulating film therebetween.
8 Citations
22 Claims
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1-5. -5. (canceled)
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6. A semiconductor device comprising:
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a drain region of a first conductivity type comprised of a semiconductor substrate; an element forming region provided on the drain region, the element forming region having a concave portion reaching the drain region; a gate electrode disposed in the concave portion; a gate insulting film provided between the gate electrode and an inner wall surface of the concave portion; a drift layer of the first conductivity type disposed in the element forming region, the drift layer being penetrated by the concave portion; a base region of the second conductivity type disposed on the drift layer so as to be in contact with the drift layer in the element forming region, the base region being penetrated by the concave portion and facing the gate electrode with the gate insulating film interposed therebetween; a source region formed on the base region in the element forming region, the source region being penetrated by the concave portion; a filler disposed inside the concave portion closer to a bottom thereof than the gate electrode, the filler being electrically conductive; and an inter-conductor insulating film disposed between the gate electrode and the filler. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method of manufacturing a semiconductor device having a drift layer of a first conductivity type on a drain region of the first conductivity type formed on a semiconductor substrate, the method comprising the steps of:
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forming a semiconductor layer of a second conductivity type different from the first conductivity type on the drain region; forming a concave portion that penetrates through the semiconductor layer and reaches the drain region; forming the drift layer along an inner wall surface of the concave portion by introducing impurities of the first conductivity type onto the semiconductor layer exposed to the inner wall surface of the concave portion; forming a base region of the second conductivity type having an exposed part exposed to the inner wall surface of the concave portion on a surface part of the semiconductor layer by introducing impurities of the second conductivity type from a surface of the semiconductor layer; forming a source region of the first conductivity type exposed to the inner wall surface of the concave portion by introducing impurities of the first conductivity type onto a surface part of the base region at an edge of the concave portion; forming an insulating film on the inner wall surface of the concave portion; filling an electrically conductive filler into a bottom part of the concave portion under a predetermined depth which is deeper than the exposed part of the base region in the concave portion after the insulating film is formed; removing the insulating film while allowing the filler to serves as a mask; forming a gate insulating film thinner than the insulating film in an area corresponding to the exposed part of the base region on an exposed surface of the inner wall surface of the concave portion exposed by the removing step, and simultaneously forming an inter-conductor insulating film on an exposed surface of the filler; and forming a gate electrode that is to face the exposed part of the base region and the filler, inside the concave portion, with the gate insulating film and the inter-conductor insulating film respectively interposed therebetween. - View Dependent Claims (21, 22)
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Specification