US4904340A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser-assisted liquid-phase etching of copper conductors
Assignee: Rateze Remote Mgmt LLC
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Filing: 1988-10-31
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Granted: 1990-02-27
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Expires: 2008-10-31
Abstract
Abstract A process for laser-assisted liquid phase etching of copper conductors which includes the use of a solution of sulfuric acid and hydrogen peroxide in contact with an integrated circuit substrate and the provision of a laser beam to select substrate areas having copper conductors to be etched. Also disclosed is an apparatus for the laser-assisted etching.
Inventors
- 👤 Robert F. Miracky
- 👤 Kantesh Doss
- 👤 Bryan Seppala
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:39
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/02; H05K3/06; C; C23; C23F; C23F1/00; C23F1/02; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H05K2203/00; H05K2203/03; H05K2203/0361; H05K2203/10; H05K2203/107; H05K2203/17; H05K2203/175; H05K3/22; H05K3/225; H05K3/38; H05K3/388; H05K3/46; H05K3/4644; H05K3/467
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
54 words
A process for laser-assisted liquid-phase etching of copper conductors, comprising the steps of: immersing a substrate having copper conductor lines on a dielectric in an etchant solution comprising sulfuric acid and hydrogen peroxide; and irradiatig select copper lines at select areas with a focused laser beam to etch said lines at said select areas.
Claim 2
Dependent Claim
54 words
A process for laser-assisted liquid-phase etching of copper conductors, comprising the steps of: immersing a substrate having copper conductor lines on a dielectric in an etchant solution comprising sulfuric acid and hydrogen peroxide; and irradiatig select copper lines at select areas with a focused laser beam to etch said lines at said select areas.
Claim 3
Dependent Claim
26 words
A process as claimed in claim 1, wherein said solution comprises about 2-10% per volume of sulfuric acid and about 1-4% per volume of hydrogen peroxide.
Claim 4
Dependent Claim
28 words
A process as claimed in claim 2, wherein said solution comprises about two percent per volume of sulfuric acid and about one percent per volume of hydrogen peroxide.
Claim 5
Dependent Claim
28 words
A process as claimed in claim 2, wherein said solution comprises about ten percent per volume of sulfuric acid and about two percent per volume of hydrogen peroxide.
Claim 6
Dependent Claim
20 words
A process as claimed in claim 1, wherein said dielectric is selected from polyimide, epoxy, silicon dioxide or silicon nitride.
Claim 7
Dependent Claim
12 words
A process as claimed in claim 5, wherein said dielectric is polyimide.
Claim 8
Dependent Claim
31 words
A process as claimed in claim 1, comprising the further step of depositing metal unetchable in sulfuric acid/hydrogen peroxide on the sides of said lines to be irradiated prior to irradiation.
Claim 9
Dependent Claim
12 words
A process as claimed in claim 7, wherein said metal comprises titanium.
Claim 10
Dependent Claim
29 words
A process as claimed in claim 1, comprising the further step of placing a thermally conductive material unetchable in sulfuric acid/hydrogen peroxide between said conductor lines and said dielectric.
Claim 11
Dependent Claim
14 words
A process as claimed in claim 9, wherein said thermally conductive material comprises titanium.
Claim 12
Dependent Claim
22 words
A process as claimed in claim 1, wherein the wavelength of said laser beam is in the range from about 200-1400 nm.
Claim 13
Dependent Claim
22 words
A process as claimed in claim 1, wherein the wavelength of said laser beam is in the range from about 400-700 nm.
Claim 14
Dependent Claim
16 words
A process as claimed in claim 1, wherein said solution further comprises a copper corrosion inhibitor.
Claim 15
Dependent Claim
19 words
A process as claimed in claim 13, wherein said inhibitor is selected from ammonium- , potassium- , or sodium-thiocyanate.
Claim 16
Dependent Claim
15 words
A process as claimed in claim 1, wherein said solution further comprises a stabilization agent.
Claim 17
Dependent Claim
13 words
A process as claimed in claim 15, wherein said stabilization agent comprises hypoxanthine.
Claim 18
Dependent Claim
29 words
A copper etchant solution for etching copper in monolithic medium film multi-chip substrates, comprising about two percent per volume sulfuric acid and about one percent per volume hydrogen peroxide.
Claim 19
Dependent Claim
29 words
A copper etchant solution for etching copper in monolithic medium film multi-chip substrates, comprising about two percent per volume sulfuric acid and about one percent per volume hydrogen peroxide.
Claim 20
Independent Claim
129 words
An apparatus for laser-assisted liquid-phase etching of integrated circuit copper conductors, comprising: means for providing a visible wavelength laser beam; shuttering means for shuttering said laser beam; a beam expander; a sample holder for receiving and retaining a workpiece; a microscope head positioned adjacent said workpiece; means for positioning during operation said microscope head relative to said workpiece; a first port having one end attached to said microscope head for receivng said laser beam and introducing said beam into said microscope head; a second port also attached to said microscope head for mounting a video camera; a third port also attached to said microscope head for introducing illumination to said sample holder; and computer means for positioning said sample holder in its x-y plane relative to said microscope head.
Claim 21
Independent Claim
129 words
An apparatus for laser-assisted liquid-phase etching of integrated circuit copper conductors, comprising: means for providing a visible wavelength laser beam; shuttering means for shuttering said laser beam; a beam expander; a sample holder for receiving and retaining a workpiece; a microscope head positioned adjacent said workpiece; means for positioning during operation said microscope head relative to said workpiece; a first port having one end attached to said microscope head for receivng said laser beam and introducing said beam into said microscope head; a second port also attached to said microscope head for mounting a video camera; a third port also attached to said microscope head for introducing illumination to said sample holder; and computer means for positioning said sample holder in its x-y plane relative to said microscope head.
Claim 22
Dependent Claim
18 words
An apparatus as claimed in claim 18, further comprising means for cooling said sample holder below ambient temperature.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-02-26 | 1993-08-28 | 1994-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-26 | 1997-08-28 | 1998-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-26 | 2001-08-28 | 2002-02-27 | $7700.00 | Window Closed / Lapsed |