Method of forming shielded gate FET with self-aligned features
First Claim
1. A method for forming a shielded gate field effect transistor, comprising:
- forming trenches in a semiconductor region of a first conductivity type;
forming a shield electrode in a bottom portion of each trench, the shield electrode being insulated from the semiconductor region by a shield dielectric;
forming a gate electrode recessed in each trench over the shield electrode, the gate electrode being insulated from the shield electrode;
using a first mask, forming a body region of a second conductivity type in the semiconductor region by implanting dopants; and
using the first mask, forming source regions of the first conductivity type in the body region by implanting dopants.
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Accused Products
Abstract
A method for forming a shielded gate field effect transistor includes the following steps. Trenches are formed in a semiconductor region of a first conductivity type. A shield electrode is formed in a bottom portion of each trench, the shield electrode being insulated from the semiconductor region by a shield dielectric. A gate electrode recessed in each trench is formed over the shield electrode, the gate electrode being insulated from the shield electrode. Using a first mask, a body region of a second conductivity type is formed in the semiconductor region by implanting dopants. Using the first mask, source regions of the first conductivity type are formed in the body region by implanting dopants.
35 Citations
34 Claims
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1. A method for forming a shielded gate field effect transistor, comprising:
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forming trenches in a semiconductor region of a first conductivity type; forming a shield electrode in a bottom portion of each trench, the shield electrode being insulated from the semiconductor region by a shield dielectric; forming a gate electrode recessed in each trench over the shield electrode, the gate electrode being insulated from the shield electrode; using a first mask, forming a body region of a second conductivity type in the semiconductor region by implanting dopants; and using the first mask, forming source regions of the first conductivity type in the body region by implanting dopants. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method for forming a shielded gate field effect transistor (FET) comprising:
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forming a mask over a semiconductor region of a first conductivity type, the mask having openings through which the semiconductor region is exposed; forming trenches extending in the semiconductor region by recessing the semiconductor region through the mask openings; forming a shield electrode in a bottom portion of each trench, the shield electrode being insulated from the semiconductor region by a shield dielectric; forming a gate electrode recessed in each trench over the shield electrode, the gate electrode being insulated from the shield electrode; using the first mask, forming a body region of a second conductivity type in the semiconductor region by implanting dopants, the first mask covering a top surface of the semiconductor region between adjacent trenches such that a substantial amount of the implant dopants enter the semiconductor region through upper trench sidewalls not covered by the recessed gate electrode; and using the first mask, forming source regions of the first conductivity type in the body region by implanting dopants. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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Specification