Method of forming dual-metal gates in semiconductor device
First Claim
1. A method of forming dual-metal gates comprising the steps of:
- providing a semiconductor substrate having a PMOS area and an NMOS area wherein dummy gates are formed in the PMOS and NMOS areas respectively;
forming an insulating interlayer on the semiconductor substrate so as to cover the dummy gates;
polishing the insulating interlayer until the dummy gates are exposed;
forming a first groove defining a first metal gate area by selectively removing one of the dummy gates formed in the PMOS and NMOS areas;
forming a first gate insulating layer and a first metal layer on an entire area of the semiconductor substrate including the first groove successively;
forming a first metal gate in the first groove by etching the first metal layer and first gate insulating layer until the insulating interlayer is exposed;
forming a second groove defining a second metal gate area by removing the remaining dummy gate;
forming a second gate insulating layer and a second metal layer on the entire area of the semiconductor substrate including the second groove; and
forming a second metal gate in the second groove by etching the second metal layer and second gate insulating layer until the insulating interlayer is exposed.
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Abstract
A method of forming dual-metal gates in a semiconductor device, including the steps of providing a semiconductor substrate having a PMOS area and an NMOS area wherein dummy gates are formed in the PMOS and NMOS areas respectively, forming an insulating interlayer on the semiconductor substrate so as to cover the dummy gates, polishing the insulating interlayer until the dummy gates are exposed, forming a first groove defining a first metal gate area by selectively removing one of the dummy gates formed in the PMOS and NMOS areas, forming a first gate insulating layer and a first metal layer on an entire area of the semiconductor substrate including the first groove successively, forming a first metal gate in the first groove by etching the first metal layer and first gate insulating layer until the insulating interlayer is exposed, forming a second groove defining a second metal gate area by removing the remaining dummy gate, forming a second gate insulating layer and a second metal layer on the entire area of the semiconductor substrate including the second groove, and forming a second metal gate in the second groove by etching the second metal layer and second gate insulating layer until the insulating interlayer is exposed.
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Citations
20 Claims
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1. A method of forming dual-metal gates comprising the steps of:
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providing a semiconductor substrate having a PMOS area and an NMOS area wherein dummy gates are formed in the PMOS and NMOS areas respectively;
forming an insulating interlayer on the semiconductor substrate so as to cover the dummy gates;
polishing the insulating interlayer until the dummy gates are exposed;
forming a first groove defining a first metal gate area by selectively removing one of the dummy gates formed in the PMOS and NMOS areas;
forming a first gate insulating layer and a first metal layer on an entire area of the semiconductor substrate including the first groove successively;
forming a first metal gate in the first groove by etching the first metal layer and first gate insulating layer until the insulating interlayer is exposed;
forming a second groove defining a second metal gate area by removing the remaining dummy gate;
forming a second gate insulating layer and a second metal layer on the entire area of the semiconductor substrate including the second groove; and
forming a second metal gate in the second groove by etching the second metal layer and second gate insulating layer until the insulating interlayer is exposed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
masking and lightly-doping ion implantation processes on the PMOS and NMOS areas in order;
depositing a nitride layer 900 to 1200 Å
thick on the semiconductor substrate including on the dummy gates;
forming spacers at both sidewalls of the dummy gates by blanket-etching the nitride layer; and
forming source/drain regions having lightly doped drain regions in the PMOS and NMOS areas below both lateral side extensions of the dummy gates including the spacers by carrying out masking and heavily-doping ion implantation processes on the PMOS and NMOS areas successively.
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6. The method of claim 1, wherein the insulating interlayer is formed 5000 to 7000 Å
- thick.
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7. The method of claim 1, wherein the dummy gates are removed by dry etch or wet etch using mask oxide layers as etch barriers.
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8. The method of claim 7, wherein the mask oxide layers are formed 500 to 800 Å
- thick.
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9. The method of claim 1, wherein the first and second gate insulating layers are formed by sequential deposition of an oxide layer, an oxynitride layer, and a high-k dielectric layer.
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10. The method of claim 1, wherein the steps of etching the first and second metal layers and the first and second gate insulating layers are carried out by CMP (chemical mechanical polishing) or etch-back.
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11. A method of forming dual-metal gates comprising the steps of:
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providing a semiconductor substrate having a PMOS area and an NMOS area wherein dummy gates are formed in the PMOS and NMOS areas, respectively;
forming an insulating interlayer on the semiconductor substrate so as to cover the dummy gates;
polishing the insulating interlayer until the dummy gates are exposed;
forming first and second grooves defining first and second metal gate areas, respectively, by removing the dummy gates;
successively forming a gate insulating layer and a first metal layer on an entire area of the semiconductor substrate including on the first and second grooves;
selectively forming a metal nitride layer by carrying out nitridation on the first metal layer formed in one of the PMOS and NMOS areas;
forming a second metal layer on the metal nitride layer and the first metal layer so as to fill up the first and second grooves; and
forming first and second metal gates in the PMOS and NMOS areas, respectively, by etching the second metal layer, first metal layer, metal nitride layer, and gate insulating layer until the insulating interlayer is exposed. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification