Power device with trenches having wider upper portion than lower portion
First Claim
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1. A method of forming a semiconductor device, comprising:
- removing portions of a silicon layer such that a plurality of trenches are formed each having sidewalls which fan out near the top of the trench to extend directly over a portion of the silicon layer adjacent each trench sidewall;
forming a first insulating layer lining the trench sidewalls;
forming a gate electrode partially filling each trench;
forming a second insulating layer in each trench, the second insulating layer extending over each gate electrode and over the portions of the silicon layer which extend directly under the trench sidewalls; and
removing exposed silicon to expose an edge of the first insulating layer in each trench, the exposed edge of the first insulating layer in each trench defining a portion of each contact opening formed between every two adjacent trenches.
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Abstract
A method of forming a semiconductor device includes the following. Removing portions of a silicon layer such that a trench having sidewalls which fan out near the top of the trench to extend directly over a portion of the silicon layer is formed in the silicon layer; and forming source regions in the silicon layer adjacent the trench sidewall such that the source regions extend into the portions of the silicon layer directly over which the trench sidewalls extend.
269 Citations
18 Claims
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1. A method of forming a semiconductor device, comprising:
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removing portions of a silicon layer such that a plurality of trenches are formed each having sidewalls which fan out near the top of the trench to extend directly over a portion of the silicon layer adjacent each trench sidewall; forming a first insulating layer lining the trench sidewalls; forming a gate electrode partially filling each trench; forming a second insulating layer in each trench, the second insulating layer extending over each gate electrode and over the portions of the silicon layer which extend directly under the trench sidewalls; and removing exposed silicon to expose an edge of the first insulating layer in each trench, the exposed edge of the first insulating layer in each trench defining a portion of each contact opening formed between every two adjacent trenches. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of forming a semiconductor device, comprising:
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removing portions of a silicon layer such that a plurality of trenches are formed each having sidewalls which fan out near the top of the trench to extend directly over a portion of the silicon layer adjacent each trench sidewall; forming a first insulating layer lining the trench sidewalls; forming a gate electrode partially filling each trench; forming a second insulating layer in each trench, the second insulating layer extending over each gate electrode and over the portions of the silicon layer which extend directly under the trench sidewalls; removing exposed portions of the silicon layer to expose an edge of the first insulating layer in each trench, the exposed edge of the first insulating layer in each trench defining a portion of each contact opening formed between every two adjacent trenches; and depositing a metal layer extending into the contact openings. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification