Trench-gated MIS devices
First Claim
1. A trench-gated MIS device in a semiconductor chip and comprising:
- a first active area including transistor cells;
a second active area including transistor cells;
a gate metal area including no transistor cells, wherein the first and second active areas are located on opposite sides of the gate metal area;
a gate metal layer overlying the gate metal area; and
a plurality of trenches formed in a pattern on a surface of the semiconductor chip, wherein the plurality of trenches extend from the first active area to the second active area and pass through the gate metal area.
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Accused Products
Abstract
In a trench-gated MIS device contact is made to the gate within the trench, thereby eliminating the need to have the gate material, typically polysilicon, extend outside of the trench. This avoids the problem of stress at the upper corners of the trench. Contact between the gate metal and the polysilicon is normally made in a gate metal region that is outside the active region of the device. Various configurations for making the contact between the gate metal and the polysilicon are described, including embodiments wherein the trench is widened in the area of contact. Since the polysilicon is etched back below the top surface of the silicon throughout the device, there is normally no need for a polysilicon mask, thereby saving fabrication costs.
87 Citations
20 Claims
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1. A trench-gated MIS device in a semiconductor chip and comprising:
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a first active area including transistor cells; a second active area including transistor cells; a gate metal area including no transistor cells, wherein the first and second active areas are located on opposite sides of the gate metal area; a gate metal layer overlying the gate metal area; and a plurality of trenches formed in a pattern on a surface of the semiconductor chip, wherein the plurality of trenches extend from the first active area to the second active area and pass through the gate metal area. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A trench-gated MIS device in a semiconductor chip and comprising:
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a first active area including transistor cells; a second active area including transistor cells; a gate metal area including no transistor cells, wherein the first and second active areas are located on opposite sides of the gate metal area; a gate metal layer overlying the gate metal area; and a plurality of trenches extending from the first active area to the second active area and passing through the gate metal area. - View Dependent Claims (9, 10)
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11. A trench-gated MIS device in a semiconductor chip and comprising:
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a first active area including transistor cells; a second active area including transistor cells; a gate metal area including no transistor cells, wherein the first and second active areas are located on opposite sides of the gate metal area; a gate metal layer overlying the gate metal area, a first plurality of trenches and a second plurality of trenches formed in a pattern on a surface of the semiconductor chip, wherein the first plurality of trenches extend from the first active area into the gate metal area, wherein the second plurality of trenches extend from the second active area into the gate metal area; and a trench formed in the gate metal area, wherein the first plurality and the second plurality of trenches are first gate fingers, wherein the trench in the gate metal area is a second gate finger, and wherein the second gate finger intersects a plurality of the first gate fingers and is perpendicular to the plurality of first gate fingers. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification