US5166093A
Expired / Lapsed
US
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Method to reduce the reflectivity of a semi-conductor metallic surface
Assignee: Micron Technology Inc
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Filing: 1991-07-31
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Granted: 1992-11-24
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Expires: 2011-07-31
Abstract
Abstract A process for layering a low reflectivity metal layer on a semiconductor wafer for decreasing the optical reflectivity and increasing the optical absorptivity of the metal layer for laser processing. The process includes: depositing a metal layer, such as aluminum, over a substrate, roughening the surface of the metal layer by chemical mechanical planarization (CMP) while injecting a silicon oxide slurry over the surface and then laser processing the metal. The roughened metal surface has an increased surface area and irregular surface features that help absorb incident laser radiation with less reflectance.
Inventors
- 👤 Malcolm Grief
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:37
CPC Classifications
H; H10; H10P; H10P52/00; H10P52/40; H10P52/403; Y; Y10; Y10S; Y10S148/00; Y10S148/138
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
89 words
A semiconductor manufacturing process comprising: a. depositing a metal layer over a substrate; b. roughening a surface of the metal layer using chemical mechanical planarization (CMP) for a period of about 10 to 40 seconds using a polishing slurry of silicon dioxide and an acid buffer at a pH of about 5.5, thereby forming a thin silicon oxide layer of about 200 to 500 Å on the metal layer to decrease a reflectivity and increase an absorptivity of the metal layer; and then. c. laser processing the metal layer.
Claim 2
Dependent Claim
89 words
A semiconductor manufacturing process comprising: a. depositing a metal layer over a substrate; b. roughening a surface of the metal layer using chemical mechanical planarization (CMP) for a period of about 10 to 40 seconds using a polishing slurry of silicon dioxide and an acid buffer at a pH of about 5.5, thereby forming a thin silicon oxide layer of about 200 to 500 Å on the metal layer to decrease a reflectivity and increase an absorptivity of the metal layer; and then. c. laser processing the metal layer.
Claim 3
Dependent Claim
100 words
In the manufacture of a semiconductor integrated circuit, a low reflectivity metallization process that adds a layer of metal over a wafer substrate comprising the steps of: a. depositing a layer of metal over the substrate; b. roughening a surface of the metal layer using chemical mechanical planarization (CMP) for a period of about 10 to 40 seconds while injecting a polishing slurry containing SiO 2 and an acid buffer at a pH of about 5.5, thereby forming a silicon dioxide layer of about 200 to 500 Å on the metal layer; and then c. laser processing the metal layer.
Claim 4
Dependent Claim
100 words
In the manufacture of a semiconductor integrated circuit, a low reflectivity metallization process that adds a layer of metal over a wafer substrate comprising the steps of: a. depositing a layer of metal over the substrate; b. roughening a surface of the metal layer using chemical mechanical planarization (CMP) for a period of about 10 to 40 seconds while injecting a polishing slurry containing SiO 2 and an acid buffer at a pH of about 5.5, thereby forming a silicon dioxide layer of about 200 to 500 Å on the metal layer; and then c. laser processing the metal layer.
Claim 5
Dependent Claim
98 words
In the manufacture of a semiconductor integrated circuit, a low reflectivity metallization process that adds a layer of aluminum over a wafer substrate comprising the steps of: a. sputtering a layer of aluminum interconnect over the substrate; b. roughening a surface of the aluminum using chemical mechanical planarization (CMP) while injecting a polishing slurry containing silica on the surface to create a thin silicon oxide layer; c. stopping the CMP process after removal of about 500 Å of aluminum; and then d. laser processing the aluminum to melt the aluminum and fill contact vias formed in the substrate.
Claim 6
Dependent Claim
98 words
In the manufacture of a semiconductor integrated circuit, a low reflectivity metallization process that adds a layer of aluminum over a wafer substrate comprising the steps of: a. sputtering a layer of aluminum interconnect over the substrate; b. roughening a surface of the aluminum using chemical mechanical planarization (CMP) while injecting a polishing slurry containing silica on the surface to create a thin silicon oxide layer; c. stopping the CMP process after removal of about 500 Å of aluminum; and then d. laser processing the aluminum to melt the aluminum and fill contact vias formed in the substrate.
Claim 7
Dependent Claim
21 words
The metallization process of claim 3 and wherein: the thin silicon oxide layer is about 200 to 500 Å in thickness.
Claim 8
Dependent Claim
23 words
The metallization process of claim 3 and wherein: the wafer CMP process is performed for a period of about 10 to 40 seconds.
Claim 9
Dependent Claim
21 words
The metallization process of claim 5 and wherein: the slurry includes an acid buffer and has a pH of about 5.5.
Claim 10
Dependent Claim
105 words
In the manufacture of a semiconductor integrated circuit, a low reflectivity metallization process that adds a layer of aluminum alloy over a wafer substrate comprising the steps of: a. sputtering a layer of aluminum alloy interconnect over the substrate; b. roughening an aluminum alloy surface using chemical mechanical planarization (CMP) process while injecting a polishing slurry containing silica on the aluminum alloy surface to create a silicon oxide layer of about 200 to 500 Å: c. stopping the CMP process after a period of from about 10 to 40 seconds; and d. laser melting the aluminum alloy layer to fill contact vias to the substrate.
Claim 11
Dependent Claim
105 words
In the manufacture of a semiconductor integrated circuit, a low reflectivity metallization process that adds a layer of aluminum alloy over a wafer substrate comprising the steps of: a. sputtering a layer of aluminum alloy interconnect over the substrate; b. roughening an aluminum alloy surface using chemical mechanical planarization (CMP) process while injecting a polishing slurry containing silica on the aluminum alloy surface to create a silicon oxide layer of about 200 to 500 Å: c. stopping the CMP process after a period of from about 10 to 40 seconds; and d. laser melting the aluminum alloy layer to fill contact vias to the substrate.
Claim 12
Dependent Claim
19 words
The metallization process of claim 7 and wherein: the (CMP) process removes less than 500 Å of aluminum alloy.
Claim 13
Dependent Claim
27 words
The metallization process of claim 8 and wherein: the aluminum alloy is aluminum alloyed with a metal selected from the group consisting of silicon, copper, and titanium.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-11-24 | 1996-05-25 | 1996-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-24 | 2000-05-25 | 2000-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-24 | 2004-05-25 | 2004-11-24 | $7700.00 | Window Closed / Lapsed |