US4514265A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bonding pads for semiconductor devices
Assignee: RCA Corp
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Filing: 1984-07-05
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Granted: 1985-04-30
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Expires: 2004-07-05
Abstract
Abstract An improved process for electroplating bonding pads, such as of gold, onto semiconductor devices is disclosed. Upon electrically connecting a masked semiconductor body and a suitable anode to the negative and positive terminals respectively of a power supply and submerging the wafer and anode into a suitable electrolyte, a modulated, rather than direct, current is applied to the electrolyte. A low stress, fine grain bonding pad layer is provided and, unexpectedly, non-planarities in the semiconductor body surface having a depth of about 1-3 microns can be substantially planarized when the thickness of the layer deposited is about 6-8 microns or more.
Inventors
- 👤 Srinivas T. Rao
- 👤 Frank Z. Hawrylo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:11
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/01; H10W72/012; H10P; H10P14/00; H10P14/40; H10P14/46; H10P14/47; H10W72/20; H10W72/251; Y; Y10; Y10S; Y10S204/00; Y10S204/09
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
130 words
In a method of electroplating one or more bonding pads onto the surface of a nonplanar semiconductor body comprising connecting the semiconductor body to a negative terminal of a power supply; connecting a suitable anode to a positive terminal of said power supply; submerging the semiconductor device and the anode into an electrolyte solution of the bonding pad material; and applying a direct current from the power supply to the electrolyte so that a layer of bonding pad material of the desired thickness is deposited onto the semiconductor body; the improvement comprising modulating the current such that it is turned off and on continuously during the deposition whereby the non-planarities are substantially planarized and a bonding pad layer having low stress, a fine grain structure and straight walls is provided.
Claim 2
Dependent Claim
130 words
In a method of electroplating one or more bonding pads onto the surface of a nonplanar semiconductor body comprising connecting the semiconductor body to a negative terminal of a power supply; connecting a suitable anode to a positive terminal of said power supply; submerging the semiconductor device and the anode into an electrolyte solution of the bonding pad material; and applying a direct current from the power supply to the electrolyte so that a layer of bonding pad material of the desired thickness is deposited onto the semiconductor body; the improvement comprising modulating the current such that it is turned off and on continuously during the deposition whereby the non-planarities are substantially planarized and a bonding pad layer having low stress, a fine grain structure and straight walls is provided.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein the non-planar devices include a depression of about 1-3 micrometers in depth.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein the bonding pad material is gold.
Claim 5
Dependent Claim
17 words
The method of claim 3 wherein the current is modulated at a duty cycle of 10-20 percent.
Claim 6
Dependent Claim
25 words
The method of claim 4 wherein a peak current density during modulation is 2 to 10 times greater than the current density employed without modulation.
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) | 1988-04-29 | 1988-10-29 | 1989-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-29 | 1992-10-29 | 1993-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-29 | 1996-10-29 | 1997-04-30 | $7700.00 | Window Closed / Lapsed |