US5679211A
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US
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Spin-on-glass etchback planarization process using an oxygen plasma to remove an etchback polymer residue
Assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
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Filing: 1995-09-18
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Granted: 1997-10-21
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Expires: 2015-09-18
Abstract
Abstract A method for improving the etch back uniformity of a SOG layer by removing an etch back resistant polymer which builds up on the SOG layer during the etch back process. According to the present invention, a first insulation layer and a SOG layer are formed on a substrate. The SOG layer is partially etched back in a fluorocarbon containing plasma which forms a polymer residue on the SOG layer surface. The SOG layer is then treated in situ with an oxygen containing plasma to remove any of the etch resistant polymer residue on the SOG layer surface. The above in situ etch and oxygen containing plasma treatment of the spin-on-glass layer are repeated until the SOG layer is etched back to the desired thickness.
Inventors
- 👤 Yuan-Chang Huang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:00
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/06; H10P95/062; H10P95/064; H10P50/00; H10P50/69; H10P50/691; H10P50/693; H10P50/695
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
93 words
The method of uniformly etching back a spin-on-glass (SOG) layer over a substrate comprising: (a) forming a first SOG layer over a substrate and curing said first SOG layer; (b) partially etching back portions of said first SOG layer and simultaneously forming a polymer residue on said SOG layer; (c) stopping said etching back; (d) exposing said first SOG layer to an oxygen containing plasma thereby removing said polymer residue from said first SOG layer; and (e) repeating steps (b) to (d) at least once until said first SOG layer is etched back.
Claim 2
Independent Claim
93 words
The method of uniformly etching back a spin-on-glass (SOG) layer over a substrate comprising: (a) forming a first SOG layer over a substrate and curing said first SOG layer; (b) partially etching back portions of said first SOG layer and simultaneously forming a polymer residue on said SOG layer; (c) stopping said etching back; (d) exposing said first SOG layer to an oxygen containing plasma thereby removing said polymer residue from said first SOG layer; and (e) repeating steps (b) to (d) at least once until said first SOG layer is etched back.
Claim 3
Dependent Claim
41 words
The method of claim 1 wherein said exposing said first SOG layer to said oxygen containing plasma includes having gasses selected from the group consisting of oxygen, N 2 O, NO, H 2 O, He/O 2 , and Ar/O 2 .
Claim 4
Dependent Claim
94 words
The method of claim 1 wherein said exposing said first SOG layer to an oxygen containing plasma is performed with a pressure in the range of about 250 to 350 mtorr, a rf power in the range of about 450 to 550 W, with an electrode gap in the range of about 1.0 to 1.6 cm, an Argon flow in the range of about 250 to 350 sccm, and an oxygen flow in the range of about 2 to 7 sccm and for a time in the range of about 20 to 50 seconds.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein said steps (b) to (d) are performed a total between two to five times.
Claim 6
Dependent Claim
21 words
The method of claim 1 wherein said etching back of said first SOG layer is performed with a fluorocarbon containing plasma.
Claim 7
Dependent Claim
110 words
The method of claim 1 wherein said etching back of said first SOG layer is performed with a flow of CH 4 in the range of about 15 to 40 sccm and a flow of CHF 3 in the range of about 50 to 100 sccm and a ratio of CH 4 :CHF 3 between about 3:10 to 6:10, and an argon flow rate of between about 300 to 400 sccm and a rf power in the range of about 450 to 550 W and at a pressure in the range of 300 to 600 mtorr and a wafer temperature between about 25° to 70° C. during the etch process.
Claim 8
Dependent Claim
32 words
The method of claim 1 wherein said substrate has an annular shape and said polymer residue is thicker in the center of the substrate than in the outer periphery of the substrate.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein said first spin-on-glass layer is formed by applying more than one spin-on-glass coating.
Claim 10
Dependent Claim
24 words
The method of claim 1 wherein said first spin-on-glass layer is composed of a material selected from the group consisting of silicate and siloxane.
Claim 11
Dependent Claim
31 words
The method of claim 1 wherein the etching back of said first SOG layer is performed with a trifluoromethane (CHF 3 ) and carbon tetrafluoride (CF 4 ) etch plasma chemistry.
Claim 12
Dependent Claim
67 words
The method of claim 1 wherein said etching back of said first spin-on-glass layer is performed with a CHF 3 flow in the range of about 15 to 40 sccm, a CF 4 flow in the range of about 50 to 100 sccm, a pressure in the range of about 300 to 600 mTorr, and a rf power of in the range of 450 to 550 Watts.
Claim 13
Dependent Claim
29 words
The method of claim 1 wherein a first silicon oxide layer is formed over said substrate and said first SOG layer is formed over said first silicon oxide layer.
Claim 14
Dependent Claim
56 words
The method of claim 1 wherein a first silicon oxide layer is formed over said substrate, and said first SOG layer is formed over said first silicon oxide layer; said first silicon oxide layer is formed by a plasma enhanced chemical vapor deposition process with a thickness in the range of about 1000 to 4000 Å.
Claim 15
Dependent Claim
87 words
The method of claim 1 wherein a first silicon oxide layer is formed on said substrate and said first SOG layer is formed on said silicon oxide layer; said first SOG layer having a thickness in the range of about 5000 to 7000 Å; and the method further includes a final etching back said first SOG layer and said first silicon oxide layer where the final etching back consumes said first SOG layer and consumes between about 1500 to 2000 Å of said first silicon oxide layer.
Claim 16
Dependent Claim
32 words
The method of claim 13 which further includes after step (e), forming a second SOG layer over the substrate surface and forming a second silicon oxide layer over said second SOG layer.
Claim 17
Independent Claim
128 words
The method of uniformly etching back a spin-on-glass (SOG) layer over a substrate comprising: (1) forming a first silicon oxide layer over the substrate surface; (2) forming a first SOG layer over said first silicon oxide layer; and curing and baking said first SOG layer; (3) etching back portions of said first SOG layer and simultaneously forming a polymer residue on said SOG layer using a fluorocarbon containing plasma; (4) stopping the etching back; (5) exposing said first SOG layer to a plasma having gasses selected from the group consisting of oxygen, N 2 O, NO, H 2 O, He/O 2 , and Ar/O 2 , thereby removing said polymer residue from said first SOG layer; (6) repeating steps (3) to (5) from between two and five times.
Claim 18
Independent Claim
128 words
The method of uniformly etching back a spin-on-glass (SOG) layer over a substrate comprising: (1) forming a first silicon oxide layer over the substrate surface; (2) forming a first SOG layer over said first silicon oxide layer; and curing and baking said first SOG layer; (3) etching back portions of said first SOG layer and simultaneously forming a polymer residue on said SOG layer using a fluorocarbon containing plasma; (4) stopping the etching back; (5) exposing said first SOG layer to a plasma having gasses selected from the group consisting of oxygen, N 2 O, NO, H 2 O, He/O 2 , and Ar/O 2 , thereby removing said polymer residue from said first SOG layer; (6) repeating steps (3) to (5) from between two and five times.
Claim 19
Dependent Claim
93 words
The method of claim 16 wherein said exposing said first SOG layer to an oxygen containing plasma is performed with a pressure in the range of about 250 to 350 mtorr, a rf power in the range of about 450 to 550 W, an electrode gap in the range of about 1.0 to 1.6 cm, an argon flow in the range of about 250 to 350 sccm, and an oxygen flow in the range of about 2 to 7 sccm and for a time in the range of about 20 to 50 seconds.
Claim 20
Dependent Claim
111 words
The method of claim 16 wherein said etching back of said first SOG layer is performed with a flow of CH 4 in the range of about 15 to 40 sccm and a flow of CHF 3 in the range of about 50 to 100 sccm, and a ratio of CH 4 :CHF 3 between about 3:10 to 6:10, and an argon flow rate of between about 300 to 400 sccm, and a rf power in the range of about 450 to 550 W, and at a pressure in the range of 300 to 600 mtorr, and at a wafer temperature between about 25° to 70° C. during the etch process.
Claim 21
Dependent Claim
32 words
The method of claim 16 wherein said substrate has an annular shape and said polymer residue is thicker in the center of the substrate than in the outer periphery of the substrate.
Claim 22
Dependent Claim
19 words
The method of claim 16 wherein said first spin-on-glass layer is formed by applying more than one spin-on-glass coating.
Claim 23
Dependent Claim
24 words
The method of claim 16 wherein said first spin-on-glass layer is composed of a material selected from the group consisting of silicate and siloxane.
Claim 24
Dependent Claim
31 words
The method of claim 16 wherein the etching back of said first SOG layer is performed with a trifluoromethane (CHF 3 ) and carbon tetrafluoride (CF 4 ) etch plasma chemistry.
Claim 25
Dependent Claim
67 words
The method of claim 16 wherein said etching back of said first spin-on-glass layer is performed with a CHF 3 flow in the range of about 15 to 40 sccm, a CF 4 flow in the range of about 50 to 100 sccm, a pressure in the range of about 300 to 600 mTorr, and a rf power of in the range of 450 to 550 Watts.
Claim 26
Dependent Claim
37 words
The method of claim 16 wherein forming said first silicon oxide layer using a plasma enhanced chemical vapor deposition process; said first silicon oxide layer having a thickness in the range of about 1000 to 4000 Å.
Claim 27
Dependent Claim
58 words
The method of claim 16 wherein forming said first SOG layer with a thickness in the range of about 5000 to 7000 Å, and the overall etching back of said first SOG layer and said first silicon oxide layer consumes said first SOG layer and consumes between about 1500 to 2000 Å of said first silicon oxide layer.
Claim 28
Independent Claim
289 words
The method of uniformly etching back a spin-on-glass (SOG) layer over a substrate comprising: (1) forming a first silicon oxide layer over the substrate surface; (2) forming a first SOG layer over said first silicon oxide layer; and curing and baking said first SOG layer; said first spin-on-glass layer is composed of a material selected from the group consisting of silicate and siloxane; said first SOG layer with a thickness in the range of about 5000 to 7000 Å; (3) etching back portions of said first SOG layer and simultaneously forming a polymer residue on said SOG layer using a fluorocarbon containing plasma comprising trifluoromethane (CHF 3 ) and carbon tetrafluoride (CF 4 ); said substrate has an annular shape and said polymer residue is thicker in the center of the substrate than in the outer periphery of the substrate; (4) stopping the etch back; (5) exposing said first SOG layer to an oxygen containing plasma removing said polymer residue from said first SOG layer; said oxygen containing plasma comprising a pressure in the range of about 250 to 350 mtorr, a rf power in the range of about 450 to 550 W, an electrode gap in the range of about 1.0 to 1.6 cm, an argon flow in the range of about 250 to 350 sccm, and an oxygen flow in the range of about 2 to 7 sccm and for a time in the range of about 20 to 50 seconds; (6) etching back etching back portions of said first SOG layer; (7) repeating steps (4) to (6) from between zero and five times, until the etch back consumes said first SOG layer and consumes between about 1500 to 2000 Å of said first silicon oxide layer.
Claim 29
Independent Claim
289 words
The method of uniformly etching back a spin-on-glass (SOG) layer over a substrate comprising: (1) forming a first silicon oxide layer over the substrate surface; (2) forming a first SOG layer over said first silicon oxide layer; and curing and baking said first SOG layer; said first spin-on-glass layer is composed of a material selected from the group consisting of silicate and siloxane; said first SOG layer with a thickness in the range of about 5000 to 7000 Å; (3) etching back portions of said first SOG layer and simultaneously forming a polymer residue on said SOG layer using a fluorocarbon containing plasma comprising trifluoromethane (CHF 3 ) and carbon tetrafluoride (CF 4 ); said substrate has an annular shape and said polymer residue is thicker in the center of the substrate than in the outer periphery of the substrate; (4) stopping the etch back; (5) exposing said first SOG layer to an oxygen containing plasma removing said polymer residue from said first SOG layer; said oxygen containing plasma comprising a pressure in the range of about 250 to 350 mtorr, a rf power in the range of about 450 to 550 W, an electrode gap in the range of about 1.0 to 1.6 cm, an argon flow in the range of about 250 to 350 sccm, and an oxygen flow in the range of about 2 to 7 sccm and for a time in the range of about 20 to 50 seconds; (6) etching back etching back portions of said first SOG layer; (7) repeating steps (4) to (6) from between zero and five times, until the etch back consumes said first SOG layer and consumes between about 1500 to 2000 Å of said first silicon oxide layer.
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