IC with recombination layer and guard ring separating VDMOS and CMOS or the like
First Claim
1. A semiconductor device comprising:
- a highly doped lower layer of a first conductivity type, formed in a substrate body,a lightly doped upper layer of said first conductivity type, formed above said highly doped lower layer within said body,a vertical MOSFET formed in a first portion of said lightly doped upper layer so that said lightly doped layer is used as a substantial drain region of said vertical MOSFET,a second circuit component formed in a second portion of said lightly doped upper layer,a guard ring formed in said lightly doped upper layer so as to separate said first and second portions, anda recombination layer for facilitating recombination of minority carriers, said recombination layer being formed between said highly doped lower layer and at least said second portion of said lightly doped upper layer, said guard ring reaching said recombination layer.
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Accused Products
Abstract
In an integrated circuit device having a highly doped bottom substrate layer of a first conductivity type, a lightly doped top layer of the first conductivity type formed on the substrate layer, a vertical MOSFET formed in the lightly doped top layer and a second circuit component, such as a CMOS, formed in the lightly doped top layer, there are further provided a guard ring and a recombination layer for preventing latchup of the second component by preventing minority carriers from moving from the vertical MOSFET to the second component. The guard ring is formed in the lightly doped top layer between the vertical MOSFET and the second component, and made of a second conductivity type single crystal semiconductor, or a first conductivity type polycrystalline silicon or an insulating material such as SiO2. The recombination layer is formed between the bottom substrate layer and the lightly doped top layer so as to separate at least the second component from the bottom substrate layer, and made of the first conductivity type polycrystalline silicon.
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Citations
18 Claims
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1. A semiconductor device comprising:
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a highly doped lower layer of a first conductivity type, formed in a substrate body, a lightly doped upper layer of said first conductivity type, formed above said highly doped lower layer within said body, a vertical MOSFET formed in a first portion of said lightly doped upper layer so that said lightly doped layer is used as a substantial drain region of said vertical MOSFET, a second circuit component formed in a second portion of said lightly doped upper layer, a guard ring formed in said lightly doped upper layer so as to separate said first and second portions, and a recombination layer for facilitating recombination of minority carriers, said recombination layer being formed between said highly doped lower layer and at least said second portion of said lightly doped upper layer, said guard ring reaching said recombination layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification