MULTI-STEP CHEMICAL MECHANICAL POLISHING OF A GATE AREA IN A FINFET
First Claim
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1. A method of manufacturing a semiconductor device, comprising:
- forming a fin structure on an insulator;
forming a gate structure over at least a portion of the fin structure and a portion of the insulator;
planarizing the gate structure by performing a chemical mechanical polishing (CMP) of the gate structure using a first slurry; and
planarizing the gate structure in a second planarization by performing a CMP of the gate structure using a second slurry different than the first slurry, the second planarization of the gate structure reducing a height of the gate structure above the fin structure in a channel region of the semiconductor device while raising a height of the gate structure surrounding the fin structure.
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Abstract
A method of manufacturing a MOSFET type semiconductor device includes planarizing a gate material layer that is deposited over a channel. The planarization is performed in a multi-step process that includes an initial “rough” planarization and then a “fine” planarization. The slurry used for the finer planarization may include added material that tends to adhere to low areas of the gate material.
22 Citations
19 Claims
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1. A method of manufacturing a semiconductor device, comprising:
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forming a fin structure on an insulator;
forming a gate structure over at least a portion of the fin structure and a portion of the insulator;
planarizing the gate structure by performing a chemical mechanical polishing (CMP) of the gate structure using a first slurry; and
planarizing the gate structure in a second planarization by performing a CMP of the gate structure using a second slurry different than the first slurry, the second planarization of the gate structure reducing a height of the gate structure above the fin structure in a channel region of the semiconductor device while raising a height of the gate structure surrounding the fin structure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for forming a MOSFET device comprising:
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forming a source, a drain, and a fin structure on an insulating layer, portions of the fin structure acting as a channel for the MOSFET;
forming a dielectric layer around the fin structure;
depositing a polysilicon layer over the fin structure, the polysilicon layer acting as a gate area for the MOSFET;
planarizing the polysilicon layer at a first rate; and
further planarizing the polysilicon layer at a second rate slower than the first rate, wherein the further planarization of the polysilicon layer reduces a height of the polysilicon layer above the fin structure while raising a height of the polysilicon layer in areas adjacent the fin structure. - View Dependent Claims (11, 13, 14, 15)
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12. (canceled)
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16. A method for forming a MOSFET device comprising:
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forming a source region on an insulating layer;
forming a drain region on the insulating layer;
forming a fin structure on the insulating layer, portions of the fin structure acting as a channel for the MOSFET;
depositing a polysilicon layer over at least portions of the fin structure and the insulating layer, the polysilicon layer acting as a gate area for the MOSFET and extending over the fin structure;
performing a first planarization of the polysilicon layer at a first rate; and
performing a second planarization of the polysilicon layer at a second rate slower than the first rate, the second planarization of the polysilicon layer reducing a height of the polysilicon layer over the fin structure while raising a height of the polysilicon layer adjacent the fin structure; and
doping the source and drain regions. - View Dependent Claims (18, 19)
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17. (canceled)
Specification