US5488015A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making an interconnect structure with an integrated low density dielectric
Assignee: Texas Instruments Inc
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Filing: 1994-05-20
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Granted: 1996-01-30
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Expires: 2014-05-20
Abstract
Abstract This invention provides a semiconductor device and process for making the same with dramatically reduced capacitance between adjacent conductors and an interlayer dielectric construction which emphasizes mechanical strength, etch compatibility, and good heat transfer. This process can include applying a solution between conductors 24, and then gelling, surface modifying, and drying the solution to form an extremely porous dielectric layer 28. A non-porous dielectric layer 30 may be formed over porous layer 28, which may complete an interlayer dielectric and provide mechanical strength, heat transfer, and a solid layer for via etch. A novel process for creating the porous dielectric layer is disclosed, which can be completed at vacuum or ambient pressures, yet results in porosity, pore size, and shrinkage of the dielectric during drying comparable to that previously attainable only by drying gels at supercritical pressure.
Inventors
- 👤 Robert H. Havemann
- 👤 Shin-puu Jeng
- 👤 Bruce E. Gnade
- 👤 Chih-Chen Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:34
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/65; H10P14/6516; H10P14/6548; H10P14/6546; H10P14/66; H10P14/668; H10P14/6681; H10P14/6684; H10P14/6686; H10P14/69; H10P14/6903; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/072; H10W20/074; H10W20/077; H10W20/40; H10W20/41; H10W20/42; H10W20/435; H10W20/45; H10W20/46; H10W20/48; H10W20/495; H10P14/63; H10P14/6326; H10P14/6342; H10P14/665; H10P14/692; H10P14/6921; H10P14/6922; Y; Y10; Y10S; Y10S148/00; Y10S148/043; Y10S148/118
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
160 words
A method of constructing a semiconductor device comprising: providing a layer of patterned conductors formed on a semiconductor substrate; depositing and gelling a layer of a precursor solution on said substrate, thereby forming a wet gel layer having porous structure; drying said wet gel layer without substantial densification of said porous structure, thereby forming a porous dielectric layer filling gaps between and covering said patterned conductors, said porous dielectric layer having a dielectric constant of less than 3.0, a porosity between 30% and 95%, and an average pore diameter of less than 80 nm; removing a top portion of said porous dielectric layer; and depositing a non-porous dielectric layer over said conductors and said porous dielectric layer to complete an interlayer dielectric, whereby the capacitive coupling between conductors on the same level is substantially reduced compared to a solid silicon dioxide dielectric and the mechanical properties of said interlayer dielectric are essentially the same as that of non-porous silicon dioxide.
Claim 2
Independent Claim
160 words
A method of constructing a semiconductor device comprising: providing a layer of patterned conductors formed on a semiconductor substrate; depositing and gelling a layer of a precursor solution on said substrate, thereby forming a wet gel layer having porous structure; drying said wet gel layer without substantial densification of said porous structure, thereby forming a porous dielectric layer filling gaps between and covering said patterned conductors, said porous dielectric layer having a dielectric constant of less than 3.0, a porosity between 30% and 95%, and an average pore diameter of less than 80 nm; removing a top portion of said porous dielectric layer; and depositing a non-porous dielectric layer over said conductors and said porous dielectric layer to complete an interlayer dielectric, whereby the capacitive coupling between conductors on the same level is substantially reduced compared to a solid silicon dioxide dielectric and the mechanical properties of said interlayer dielectric are essentially the same as that of non-porous silicon dioxide.
Claim 3
Dependent Claim
39 words
The method of claim 1, further comprising creating one or more metal-filled vias passing through said non-porous dielectric layer to provide electrical contact to said patterned conductors and forming a second layer of conductors over said non-porous dielectric layer.
Claim 4
Dependent Claim
26 words
The method of claim 1, further comprising surface treating said wet gel to render said wet gel hydrophobic prior to said drying said wet gel step.
Claim 5
Dependent Claim
21 words
The method of claim 1, further comprising before said porous dielectric forming step, conformally applying a passivation layer to said conductors.
Claim 6
Dependent Claim
33 words
The method of claim 1, wherein said step of depositing a non-porous dielectric layer comprises depositing bottom and top sublayers, said bottom sublayer deposited conformally and said top sublayer being a planarized layer.
Claim 7
Dependent Claim
17 words
The method of claim 5, wherein said bottom sublayer is deposited by a chemical vapor deposition process.
Claim 8
Dependent Claim
23 words
The method of claim 1, wherein said removing a top portion of said porous dielectric layer step comprises mechanically polishing said semiconductor device.
Claim 9
Dependent Claim
23 words
The method of claim 1, wherein said removing a top portion of said porous dielectric layer step exposes the tops of said conductors.
Claim 10
Dependent Claim
17 words
The method of claim 1, wherein said non-porous dielectric layer comprises the majority of said interlayer dielectric.
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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 |