EP0226385B1
Expired / Lapsed
EP
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Rhodium capped gold ic metallization
Assignee: Tektronix Inc
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Filing: 1986-12-02
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Granted: 1990-08-22
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Expires: 2006-12-02
Abstract
No abstract record available.
Inventors
- 👤 Stephen R. Early
- 👤 Daniel Grogan
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 08:09
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/056; H10W20/057; H10W20/40; H10W20/41; H10W20/425; H10W20/44; H10W20/4403; H10W20/4432; H10W20/4435
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
269 words
A metallization process for interconnecting elements on an integrated circuit chip, comprising: forming electrical contact openings (16, 18) in a first, surface dielectric layer (12) on the chip; depositing a first metallization (26, 28) on the first dielectric layer in accordance with a first predetermined pattern, including into said contact openings, the first metallization having a peripheral edge defining sidewalls (30) generally normal to the first dielectric layer (12); annealing the chip at a temperature T sufficient to relieve mechanical stresses in the first metallization (26); depositing a second dielectric layer (34) on the chip to cover the first dielectric (12) and the first metallization (26) including the sidewalls thereof (30); and depositing a second metallization (46) on the second dielectric (34) in accordance with a second predetermined pattern, including a contact (40) electrically interconnecting the second metallization and a portion of the first metallization and a conduction line (36, 38) at a predetermined spacing from one of the sidewalls of the first metallization; the step of depositing the first metallization including sequentially depositing a layer of a first metal (26) onto the first dielectric (12) and into the contact openings (16) and a layerof a second metal (28) atop the first metal and extending to edges coextensive with said sidewalls; the first metal (26) being a highly conductive metal having a first rigidity characteristic and the second metal (28) having a second rigidity characteristic, wherein the second metal has a Young's modulus higher than the Young's modulus of the first metal at annealing temperature Tand thereby maintains the first metallization through annealing in a shape substantially as deposited.
Claim 2
Dependent Claim
269 words
A metallization process for interconnecting elements on an integrated circuit chip, comprising: forming electrical contact openings (16, 18) in a first, surface dielectric layer (12) on the chip; depositing a first metallization (26, 28) on the first dielectric layer in accordance with a first predetermined pattern, including into said contact openings, the first metallization having a peripheral edge defining sidewalls (30) generally normal to the first dielectric layer (12); annealing the chip at a temperature T sufficient to relieve mechanical stresses in the first metallization (26); depositing a second dielectric layer (34) on the chip to cover the first dielectric (12) and the first metallization (26) including the sidewalls thereof (30); and depositing a second metallization (46) on the second dielectric (34) in accordance with a second predetermined pattern, including a contact (40) electrically interconnecting the second metallization and a portion of the first metallization and a conduction line (36, 38) at a predetermined spacing from one of the sidewalls of the first metallization; the step of depositing the first metallization including sequentially depositing a layer of a first metal (26) onto the first dielectric (12) and into the contact openings (16) and a layerof a second metal (28) atop the first metal and extending to edges coextensive with said sidewalls; the first metal (26) being a highly conductive metal having a first rigidity characteristic and the second metal (28) having a second rigidity characteristic, wherein the second metal has a Young's modulus higher than the Young's modulus of the first metal at annealing temperature Tand thereby maintains the first metallization through annealing in a shape substantially as deposited.
Claim 3
Dependent Claim
58 words
A process according to Claim 1 in which the rigidity characteristics of the first (26) and second (28) metals vary with temperature and at annealing temperature T the second metal has a TfT M2 ratio less than the ratio Trr M1, where T M1 and T M2 are the melting temperatures of the first and second metals, respectively.
Claim 4
Dependent Claim
75 words
A process according to Claim 1 or 2 in which the first (26) and second (28) metals each have a characteristic resistivity, the resistivity of the first metal (26) being less than that of the second metal (28), the depositing step including depositing each of the first and second metals to a predetermined thickness, the thickness of the layer of second metal being substantially less than the thickness of the layer of the first metal.
Claim 5
Dependent Claim
60 words
A process according to any preceding Claim in which the first (26) and second (28) metals have an interdiffusivity at annealing temperature such that they are mutually adherent but low enough at annealing temperature T that diffusion of the second metal into the first metal is limited to a small fraction of the thickness of the layer of first metal.
Claim 6
Dependent Claim
23 words
A process according to any preceding Claim in which the first (26) and second (28) metals are corrosion-resistant metals and are additively deposited.
Claim 7
Dependent Claim
16 words
A process according to any preceding Claim in which the first and second metals are electrodeposited.
Claim 8
Dependent Claim
38 words
A process according to any preceding Claim in which at least the second metal (28) is corrosion-and oxidation-resistant, the second metal being deposited on the first metal (26) before oxidation or corrosion of the first metal can occur.
Claim 9
Dependent Claim
38 words
A process according to any preceding Claim in which the sequential deposition step includes electrodepositing one of gold, silver and copper as said first metal (26) and electrodepositing one of rhodium and platinum as the second metal (28).
Claim 10
Dependent Claim
30 words
A process according to Claim 8, in which the first metal (26) is silver or copper, including electrodepositing the second metal (28) before the first metal can corrode or oxidize.
Claim 11
Dependent Claim
20 words
A process according to Claim 8 in which the first metal (26) is gold and the second metal is rhodium.
Claim 12
Dependent Claim
68 words
A process according to Claim 8 in which the first metal (26) is electrodeposited to a first thickness; the second metal (28) is electrodeposited to a second thickness less by an order of magnitude than the first thickness; and annealing temperature T is limited to a temperature atwhich diffusion of the first metal into the second metal is less by an order of magnitude than the second thickness.
Claim 13
Dependent Claim
75 words
A process according to Claim 1 in which the first metal (26) is a Group IB metal and the second metal (28) is a corrosion- and oxidation-resistant platinum group metal, the sequential deposition of the first (26) and second (28) metals being arranged so that the second metal is deposited on the first metal in the substantial absence of oxidation and corrosion thereon, thereby providing a corrosion and oxidation free contact for the second metallization.
References Cited (Backward Citations)
No citation records indexed.
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