US5487999A
Expired / Lapsed
US
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Method for fabricating a penetration limited contact having a rough textured surface
Assignee: Micron Technology Inc
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Filing: 1994-11-22
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Granted: 1996-01-30
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Expires: 2014-11-22
Abstract
Abstract A method for forming contacts for establishing an electrical connection with contact locations on a semiconductor die is provided. The contacts are formed as raised members mounted on a compliant substrate. Each contact includes a rough textured surface having asperities adapted to penetrate the contact location on the die to a limited penetration depth. The height of the asperities is between about 1000 ANGSTROM to 10,000 ANGSTROM . The textured surface and asperities are formed by electroplating a rough metal layer on a raised metal contact or by etching a surface of a raised metal contact. In an illustrative embodiment the contacts comprise microbumps formed on a compliant polyimide substrate. For forming an interconnect suitable for establishing a temporary electrical connection with an unpackaged semiconductor die, the polyimide substrate is attached to a rigid substrate, such as silicon, having a coefficient of thermal expansion that matches that of a silicon die. The interconnect can then be used with a carrier for testing the unpackaged die.
Inventors
- 👤 Warren M. Farnworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:19
CPC Classifications
G; G01; G01R; G01R1/00; G01R1/02; G01R1/04; G01R1/0408; G01R1/0433; G01R1/0441; G01R1/0466; G01R1/0483; G01R31/00; G01R31/28; G01R31/2851; G01R31/2893; H; H05; H05K; H05K3/00; H05K3/40; H05K3/4007; H10; H10P; H10P72/00; H10P72/70; H10P72/74; H10P74/00; H10P74/23; H10W; H10W70/00; H10W70/60; H10W70/62; H10W70/65; H10W70/67; H10W70/68; H10W90/00; H10W90/701; H10W99/00; G01R1/06; G01R1/067; G01R1/06711; G01R1/06755; G01R1/06761; G01R3/00; G01R31/282; G01R31/2831; G01R31/2855; G01R31/286; G01R31/2863; H05K2201/00; H05K2201/01; H05K2201/0104; H05K2201/0133; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0347; H05K2201/0364; H05K2201/0367; H05K2201/0388; H05K2201/0394; H05K2201/09; H05K2201/09209; H05K2201/09372; H05K2201/09481; H05K2201/095; H05K2201/09563; H05K2203/00; H05K2203/03; H05K2203/0307; H05K2203/07; H05K2203/0703; H05K2203/0723; H05K3/0058; H05K3/0067; H05K3/42; H05K3/423; H10W70/654; H10W70/655; H10W70/681; H10W72/00; H10W72/071; H10W72/075; H10W72/07502; H10W72/07504; H10W72/50; H10W72/531; H10W72/536; H10W90/20; H10W90/24; H10W90/721; H10W90/722
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
72 words
A method for forming a contact structure for forming an electrical connection with a contact location on a semiconductor die, said method comprising: forming a compliant substrate; mounting a raised contact on the substrate; forming a rough textured surface on the raised contact, said rough textured surface including raised asperities adapted to penetrate said contact location to a penetration depth; and establishing an electrical path on the substrate to the raised contact.
Claim 2
Independent Claim
72 words
A method for forming a contact structure for forming an electrical connection with a contact location on a semiconductor die, said method comprising: forming a compliant substrate; mounting a raised contact on the substrate; forming a rough textured surface on the raised contact, said rough textured surface including raised asperities adapted to penetrate said contact location to a penetration depth; and establishing an electrical path on the substrate to the raised contact.
Claim 3
Dependent Claim
24 words
The method as claimed in claim 1 and further comprising: forming the rough textured surface as a metal layer using an electrolytic plating process.
Claim 4
Dependent Claim
20 words
The method as claimed in claim 1 and further comprising: forming the rough textured surface by etching the raised contact.
Claim 5
Dependent Claim
34 words
The method as claimed in claim 1 and wherein: mounting the raised contact is by etching an opening in the substrate and filling the opening with a metal plug having an exposed bump. .
Claim 6
Dependent Claim
28 words
The method as claimed in claim 1 and wherein: establishing the electrical path is using a conductive trace formed on the substrate and attached to the raised contact.
Claim 7
Dependent Claim
37 words
The method as claimed in claim 1 and further comprising: forming an interconnect by attaching the substrate to a rigid substrate formed of a material selected from the group consisting of silicon, silicon-on-sapphire, silicon-on-glass, germanium, and ceramic.
Claim 8
Dependent Claim
18 words
The method as claimed in claim 6 and further comprising testing an unpackaged semiconductor die using the interconnect.
Claim 9
Dependent Claim
16 words
The method as claimed in claim 1 and wherein: the raised contact is convex in shape.
Claim 10
Dependent Claim
17 words
The method as claimed in claim 1 and wherein: the raised contact is generally conical in shape.
Claim 11
Dependent Claim
23 words
The method as claimed in claim 1 and wherein: the asperities on the raised contact have a height of from 1000Å to 10,000Å.
Claim 12
Independent Claim
79 words
A method for forming a contact structure for forming an electrical connection with a contact location on a semiconductor die, said method comprising: forming an electrically insulating compliant substrate; forming an opening through the substrate; filling the opening with a conductive material and forming a bump on the conductive material out of a base metal; forming a rough textured surface on the bump, said textured surface including asperities adapted to penetrate into said contact location to a penetration depth.
Claim 13
Independent Claim
79 words
A method for forming a contact structure for forming an electrical connection with a contact location on a semiconductor die, said method comprising: forming an electrically insulating compliant substrate; forming an opening through the substrate; filling the opening with a conductive material and forming a bump on the conductive material out of a base metal; forming a rough textured surface on the bump, said textured surface including asperities adapted to penetrate into said contact location to a penetration depth.
Claim 14
Dependent Claim
30 words
The method as claimed in claim 11 and wherein: forming a rough textured surface is with an electrolytic plating process in which process parameters are controlled to form the asperities.
Claim 15
Dependent Claim
23 words
The method as claimed in claim 12 and wherein: a concentration of brighteners in the electrolytic solution is controlled to form an asperities.
Claim 16
Dependent Claim
19 words
The method as claimed in claim 13 and wherein: the asperities have a height of from 1000Å to 10,000Å.
Claim 17
Dependent Claim
19 words
The method as claimed in claim 11 and wherein forming a rough textured surface is by etching the bump.
Claim 18
Dependent Claim
22 words
The method as claimed in claim 11 and further comprising: attaching the compliant substrate to a rigid substrate to form an interconnect.
Claim 19
Independent Claim
90 words
A method for forming a contact structure for establishing an electrical connection with a contact location on a semiconductor die, said method comprising: providing a compliant substrate; forming an electrically conductive trace on the compliant substrate; etching an opening through the compliant substrate to the conductive trace; forming a raised contact on the opening in electrical communication with the conductive trace; forming a rough textured surface on the raised contact having pointed asperities of from 1000Å to 10,000Å adapted to penetrate into the contact location to a limited penetration depth.
Claim 20
Independent Claim
90 words
A method for forming a contact structure for establishing an electrical connection with a contact location on a semiconductor die, said method comprising: providing a compliant substrate; forming an electrically conductive trace on the compliant substrate; etching an opening through the compliant substrate to the conductive trace; forming a raised contact on the opening in electrical communication with the conductive trace; forming a rough textured surface on the raised contact having pointed asperities of from 1000Å to 10,000Å adapted to penetrate into the contact location to a limited penetration depth.
Claim 21
Dependent Claim
25 words
The method as claimed in claim 17 and wherein: forming a rough textured surface is by electroplating a rough metal layer on the raised contact.
Claim 22
Dependent Claim
20 words
The method as claimed in claim 18 and further comprising: roughening a surface of the raised contact prior to electroplating.
Claim 23
Dependent Claim
20 words
The method as claimed in claim 17 and wherein: forming a rough textured surface is by etching the raised contact.
Claim 24
Dependent Claim
25 words
The method as claimed in claim 20 and wherein: etching is using a process selected from the group consisting of dry etching and wet etching.
Claim 25
Dependent Claim
18 words
The method as claimed in claim 17 and wherein: the complaint substrate is formed of a polyimide material.
Claim 26
Independent Claim
79 words
A method for forming a contact structure for establishing an electrical connection with a contact location on a semiconductor die, said method comprising: providing an electrically insulative compliant substrate; forming a raised contact of a base metal on the substrate; forming a rough surface on the raised contact by etching the base metal to form asperities adapted to penetrate the contact location to a limited penetration depth; and establishing an electrical path on the substrate to the raised contact.
Claim 27
Independent Claim
79 words
A method for forming a contact structure for establishing an electrical connection with a contact location on a semiconductor die, said method comprising: providing an electrically insulative compliant substrate; forming a raised contact of a base metal on the substrate; forming a rough surface on the raised contact by etching the base metal to form asperities adapted to penetrate the contact location to a limited penetration depth; and establishing an electrical path on the substrate to the raised contact.
Claim 28
Dependent Claim
39 words
The method as claimed in claim 23 and wherein: the insulative substrate comprises polyimide tape etched with an opening for the raised contact and a conductive trace is formed on the substrate in electrical communication with the raised contact.
Claim 29
Dependent Claim
27 words
The method as claimed in claim 23 and further comprising: attaching the compliant substrate to a rigid substrate to form an interconnect for testing unpackaged semiconductor dice.
Claim 30
Dependent Claim
19 words
The method as claimed in claim 23 and wherein: the asperities have a height of about 1000Å to 10,000Å.
Claim 31
Dependent Claim
26 words
The method as claimed in claim 23 and wherein: the etching process is selected from the group of processes consisting of wet etching and dry etching.
Claim 32
Dependent Claim
18 words
The method as claimed in claim 23 and wherein: the etching process is performed using a wet etchant.
Claim 33
Dependent Claim
15 words
The method as claimed in claim 28 and wherein: the wet etchant is an acid.
Claim 34
Independent Claim
91 words
A method for forming a contact structure for establishing an electrical connection with a contact location on a semiconductor die, said method comprising: forming a compliant substrate; forming an electrically conductive trace on the compliant substrate; etching an opening through the compliant substrate to the conductive trace; filling the opening with a conductive material in electrical communication with the conductive trace; forming a raised contact on the conductive material; and forming a rough textured surface on the raised contact adapted to penetrate into the contact location to a limited penetration depth.
Claim 35
Independent Claim
91 words
A method for forming a contact structure for establishing an electrical connection with a contact location on a semiconductor die, said method comprising: forming a compliant substrate; forming an electrically conductive trace on the compliant substrate; etching an opening through the compliant substrate to the conductive trace; filling the opening with a conductive material in electrical communication with the conductive trace; forming a raised contact on the conductive material; and forming a rough textured surface on the raised contact adapted to penetrate into the contact location to a limited penetration depth.
Claim 36
Dependent Claim
24 words
The method as claimed in claim 30 and wherein: forming a rough textured surface is by electroplating a metal layer on the raised contact.
Claim 37
Dependent Claim
20 words
The method as claimed in claim 30 and wherein: forming a rough textured surface is by etching the raised contact.
Claim 38
Dependent Claim
18 words
The method as claimed in claim 30 and wherein: the complaint substrate is formed of a polyimide material.
Claim 39
Dependent Claim
21 words
The method as claimed in claim 30 and wherein the raised contact and conductive material are formed of a same metal.
Claim 40
Dependent Claim
21 words
The method as claimed in claim 30 and wherein the raised contact and conductive material are formed by an electroplating process.
Claim 41
Dependent Claim
19 words
The method as claimed in claim 30 and wherein the asperities have a height of from 1000Å to 10,000Å.
Claim 42
Dependent Claim
18 words
The method as claimed in claim 30 and further comprising testing a semiconductor die using the contact structure.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-29 | 1999-07-31 | 2000-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-29 | 2003-07-31 | 2004-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-29 | 2007-07-31 | 2008-01-30 | $7700.00 | Window Closed / Lapsed |