METHOD FOR FORMING SHIELDED GATE OF MOSFET
First Claim
1. A method for forming a shielded gate of a MOSFET, comprising steps of:
- (a) providing a semiconductor substrate having at least one trench;
(b) forming a bottom gate oxide region and a shielded gate poly region in said trench of said semiconductor substrate;
(c) forming an inter-poly oxide region on said shielded gate poly region through high temperature plasma deposition, poly etching back and oxide etching back; and
(d) forming a gate oxide region and a gate poly region on said inter-poly oxide region.
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Abstract
A method for forming a shielded gate of a MOSFET includes steps as following: providing a semiconductor substrate having at least one trench, forming a bottom gate oxide region and a shielded gate poly region in the trench of the semiconductor substrate, forming an inter-poly oxide region on the shielded gate poly region through high temperature plasma deposition, poly etching back and oxide etching back; and forming a gate oxide region and a gate poly region on the inter-poly oxide region. By utilizing the etching back processes in replace of traditional chemical mechanical polishing processes, the manufacturing cost of manufacturing a shielded gate structure is reduced, and the total cost of manufacturing a FET is also reduced. Meanwhile, the gate charge is effectively reduced due to the shielded gate structure, so that the performance of a MOSFET is enhanced.
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Citations
10 Claims
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1. A method for forming a shielded gate of a MOSFET, comprising steps of:
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(a) providing a semiconductor substrate having at least one trench; (b) forming a bottom gate oxide region and a shielded gate poly region in said trench of said semiconductor substrate; (c) forming an inter-poly oxide region on said shielded gate poly region through high temperature plasma deposition, poly etching back and oxide etching back; and (d) forming a gate oxide region and a gate poly region on said inter-poly oxide region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification