US5827437A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-step metallization etch
Assignee: Lam Research Corp
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Filing: 1996-05-17
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Granted: 1998-10-27
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Expires: 2016-05-17
Abstract
Abstract A method for etching through a selected portion of a metallization layer of a wafer's layer stack in a high density plasma processing chamber includes performing a main etch by etching at least partially through the metallization layer of the layer stack with a main-etch etchant source gas that includes essentially Cl2 and BCl3 having a first Cl2:BCl3 flow ratio. Thereafter, an over etch is performed by etching to a layer underlying the metallization layer with an over-etch etchant source gas that includes essentially Cl2 and BCl3 having a second Cl2:BCl3 flow ratio that is higher than the first Cl2:BCl3 flow ratio. The method may further include the step of performing a barrier layer etching step for etching a barrier layer of the layer stack prior to performing the over etch.
Inventors
- 👤 Richard Yen-chang Yang
- 👤 Kenlin Chenjin Huang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:18
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
124 words
In a high density plasma processing chamber, a method for etching through a selected portion of a metallization layer of a wafer's layer stack, said method comprising: performing a main etch by etching at least partially through said metallization layer of said layer stack with a main-etch etchant source gas that comprises Cl 2 and BCl 3 and having a first Cl 2 :BCl 3 flow ratio; and thereafter, performing an over etch by etching through a remainder of said metallization layer to a layer underlying said metallization layer with an over-etch etchant source gas that comprises Cl 2 and BCl 3 and having a second Cl 2 :BCl 3 flow ratio that is higher than said first Cl 2 :BCl 3 flow ratio.
Claim 2
Dependent Claim
124 words
In a high density plasma processing chamber, a method for etching through a selected portion of a metallization layer of a wafer's layer stack, said method comprising: performing a main etch by etching at least partially through said metallization layer of said layer stack with a main-etch etchant source gas that comprises Cl 2 and BCl 3 and having a first Cl 2 :BCl 3 flow ratio; and thereafter, performing an over etch by etching through a remainder of said metallization layer to a layer underlying said metallization layer with an over-etch etchant source gas that comprises Cl 2 and BCl 3 and having a second Cl 2 :BCl 3 flow ratio that is higher than said first Cl 2 :BCl 3 flow ratio.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein the flow rate for the main-etch etchant source gas is greater than the flow rate of the over-etch etchant source gas.
Claim 4
Dependent Claim
30 words
The method of claim 2 wherein the flow rate for the Cl 2 in the main-etch etchant source gas is at least about 50 standard cubic centimeters per minute (sccm).
Claim 5
Dependent Claim
30 words
The method of claim 3 wherein the flow rate for the Cl 2 in the main-etch etchant source gas is at least about 200 standard cubic centimeters per minute (sccm).
Claim 6
Dependent Claim
35 words
The method of claim 1 wherein the chamber pressure within the plasma processing chamber during the main etch step is greater than the chamber pressure within the plasma processing chamber during the over etch step.
Claim 7
Dependent Claim
27 words
The method of claim 5 wherein the chamber pressure within the plasma processing chamber during the main etch step is about 5 mTorr to about 25 mTorr.
Claim 8
Dependent Claim
27 words
The method of claim 6 wherein the chamber pressure within the plasma processing chamber during the main etch step is about 12 mTorr to about 18 mTorr.
Claim 9
Dependent Claim
23 words
The method of claim 7 wherein the chamber pressure within the plasma processing chamber during the main etch step is about 15 mTorr.
Claim 10
Dependent Claim
30 words
The method of claim 7 wherein the flow rate for the Cl 2 in the main-etch etchant source gas is at least about 150 standard cubic centimeters per minute (sccm).
Claim 11
Dependent Claim
30 words
The method of claim 9 wherein the flow rate for the Cl 2 in the main-etch etchant source gas is at least about 200 standard cubic centimeters per minute (sccm).
Claim 12
Dependent Claim
34 words
The method of claim 1 wherein the method further includes the step of performing a barrier layer etching step for etching a barrier layer of said layer stack prior to performing said over etch.
Claim 13
Dependent Claim
21 words
The method of claim 1 wherein a plasma in said plasma processing chamber is energized through capacitively coupled parallel electrode plates.
Claim 14
Dependent Claim
21 words
The method of claim 1 wherein a plasma in said plasma processing chamber is energized through an inductively coupled RF source.
Claim 15
Dependent Claim
20 words
The method of claim 13 wherein a plasma in said plasma processing chamber is energized by a transformer-coupled plasma source.
Claim 16
Dependent Claim
126 words
In a high density plasma processing chamber, a method for minimizing microloading and profile microloading while etching through a metallization layer of a wafer's layer stack, said method comprising: performing a main etch by etching at least partially through said metallization layer of said layer stack with a main-etch etchant source gas that comprises Cl 2 and BCl 3 and having a first Cl 2 :BCl 3 flow ratio; and thereafter, performing an over etch by etching through a remainder of said metallization layer to a layer underlying said metallization layer with an over-etch etchant source gas that comprises Cl 2 and BCl 3 and having a second Cl 2 :BCl 3 flow ratio that is higher than said first Cl 2 :BCl 3 flow ratio.
Claim 17
Dependent Claim
126 words
In a high density plasma processing chamber, a method for minimizing microloading and profile microloading while etching through a metallization layer of a wafer's layer stack, said method comprising: performing a main etch by etching at least partially through said metallization layer of said layer stack with a main-etch etchant source gas that comprises Cl 2 and BCl 3 and having a first Cl 2 :BCl 3 flow ratio; and thereafter, performing an over etch by etching through a remainder of said metallization layer to a layer underlying said metallization layer with an over-etch etchant source gas that comprises Cl 2 and BCl 3 and having a second Cl 2 :BCl 3 flow ratio that is higher than said first Cl 2 :BCl 3 flow ratio.
Claim 18
Dependent Claim
108 words
In a high density plasma processing chamber, a method for minimizing microloading and profile microloading while etching through a metallization layer of a wafer's layer stack, said method comprising: performing a main etch by etching at least partially through said metallization layer of said layer stack with a main-etch etchant source gas that comprises Cl 2 and BCl 3 and having a first Cl 2 :BCl 3 flow ratio; and thereafter, performing an over etch by etching through a remainder of said metallization layer to a layer underlying said metallization layer with an over-etch etchant source gas that comprises Cl 2 and having substantially no BCl 3 .
Claim 19
Dependent Claim
108 words
In a high density plasma processing chamber, a method for minimizing microloading and profile microloading while etching through a metallization layer of a wafer's layer stack, said method comprising: performing a main etch by etching at least partially through said metallization layer of said layer stack with a main-etch etchant source gas that comprises Cl 2 and BCl 3 and having a first Cl 2 :BCl 3 flow ratio; and thereafter, performing an over etch by etching through a remainder of said metallization layer to a layer underlying said metallization layer with an over-etch etchant source gas that comprises Cl 2 and having substantially no BCl 3 .
Claim 20
Dependent Claim
27 words
The method of claim 15 wherein the flow rate for the main-etch etchant source gas is greater than the flow rate of the over-etch etchant source gas.
Claim 21
Dependent Claim
35 words
The method of claim 17 wherein the chamber pressure within the plasma processing chamber during the main etch step is greater than the chamber pressure within the plasma processing chamber during the over etch step.
Claim 22
Dependent Claim
34 words
The method of claim 18 wherein the method further includes the step of performing a barrier layer etching step for etching a barrier layer of said layer stack prior to performing said over etch.
Claim 23
Independent Claim
125 words
A method of manufacturing an integrated circuit having components formed on a semiconductor wafer die, said die having thereon etched layers of a layer stack, said method comprising: performing a main etch by etching at least partially through said metallization layer of said layer stack with a main-etch etchant source gas that comprises Cl 2 and BCl 3 and having a first Cl 2 :BCl 3 flow ratio; and thereafter, performing an over etch by etching through a remainder of said metallization layer to a layer underlying said metallization layer with an over-etch etchant source gas that comprises Cl 2 and BCl 3 and having a second Cl 2 :BCl 3 flow ratio that is higher than said first Cl 2 :BCl 3 flow ratio.
Claim 24
Independent Claim
125 words
A method of manufacturing an integrated circuit having components formed on a semiconductor wafer die, said die having thereon etched layers of a layer stack, said method comprising: performing a main etch by etching at least partially through said metallization layer of said layer stack with a main-etch etchant source gas that comprises Cl 2 and BCl 3 and having a first Cl 2 :BCl 3 flow ratio; and thereafter, performing an over etch by etching through a remainder of said metallization layer to a layer underlying said metallization layer with an over-etch etchant source gas that comprises Cl 2 and BCl 3 and having a second Cl 2 :BCl 3 flow ratio that is higher than said first Cl 2 :BCl 3 flow ratio.
Claim 25
Dependent Claim
134 words
In a high density plasma processing chamber, a method for etching through a selected portion of a metallization layer of a wafer's layer stack, said method comprising: performing a main etch by etching at least partially through said metallization layer of said layer stack with a main-etch etchant source gas that comprises Cl 2 and BCl 3 , said main etch is performed using a first chamber pressure within said high density plasma processing chamber; thereafter, performing an over etch by etching through a remainder of said metallization layer to a layer underlying said metallization layer with an over-etch etchant source gas that comprises Cl 2 and BCl 3 said over etch is performed using a second chamber pressure within said high density plasma processing chamber that is lower than said first chamber pressure.
Claim 26
Dependent Claim
134 words
In a high density plasma processing chamber, a method for etching through a selected portion of a metallization layer of a wafer's layer stack, said method comprising: performing a main etch by etching at least partially through said metallization layer of said layer stack with a main-etch etchant source gas that comprises Cl 2 and BCl 3 , said main etch is performed using a first chamber pressure within said high density plasma processing chamber; thereafter, performing an over etch by etching through a remainder of said metallization layer to a layer underlying said metallization layer with an over-etch etchant source gas that comprises Cl 2 and BCl 3 said over etch is performed using a second chamber pressure within said high density plasma processing chamber that is lower than said first chamber pressure.
Claim 27
Dependent Claim
18 words
The method of claim 21 wherein said first chamber pressure is about 5 mTorr to about 25 mTorr.
Claim 28
Dependent Claim
18 words
The method of claim 22 wherein said first chamber pressure is about 12 mTorr to about 18 mTorr.
Claim 29
Dependent Claim
14 words
The method of claim 23 wherein said first chamber pressure is about 15 mTorr.
Claim 30
Dependent Claim
35 words
The method of claim 2 wherein the chamber pressure within the plasma processing chamber during the main etch step is greater than the chamber pressure within the plasma processing chamber during the over etch step.
References Cited (Backward Citations)
US5421891A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-10-26 | 2002-04-27 | 2002-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-26 | 2006-04-27 | 2006-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-26 | 2010-04-27 | 2010-10-27 | $7700.00 | Window Closed / Lapsed |