US4950620A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making integrated circuit with doped silicon dioxide load elements
Assignee: Dallas Semiconductor Corp
•
Filing: 1988-09-30
•
Granted: 1990-08-21
•
Expires: 2008-09-30
Abstract
Abstract An integrated circuit which uses vertical current flow through arsenic-implanted oxide films to provide low-current loads. These load elements provide a compact four-transistor SRAM which has very simple fabrication and very low power consumption.
Inventors
- 👤 Thomas E. Harrington, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:37
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/40; H10D1/47; G; G11; G11C; G11C11/00; G11C11/21; G11C11/34; G11C11/40; G11C11/41; G11C11/412; G11C11/413; G11C11/417; H10B; H10B10/00; H10B10/15; Y; Y10; Y10S; Y10S257/00; Y10S257/903; Y10S257/904
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
170 words
A process for making an integrated circuit, comprising the steps of: (a) providing a substrate including monocrystalline semiconductor portions therein; (b) forming a high-quality thin dielectric film on said monocrystalline semiconductor portions; (c) covering said thin dielectric film with a thin capping layer; (d) introducing dopant atoms into a predetermined area portion of said thin dielectric film, to induce a significantly increased leakage current therein; (e) providing a gate layer over said capping layer, said gate layer being a thin film conductive layer which is patterned to form the gate electrode of multiple operable insulated-gate field-effect transistors in predetermined locations, other portions of said high-quality thin dielectric film providing the gate dielectric of said transistors, and said monocrystalline semiconductor portions providing the channel of at least some of said transistors; and (f) interconnecting one of said transistors in circuit paths to implement a desired electrical function, wherein some of said circuit paths include current flowing vertically through said increased-leakage-current portions of said high-quality thin film to provide electrical load elements.
Claim 2
Dependent Claim
170 words
A process for making an integrated circuit, comprising the steps of: (a) providing a substrate including monocrystalline semiconductor portions therein; (b) forming a high-quality thin dielectric film on said monocrystalline semiconductor portions; (c) covering said thin dielectric film with a thin capping layer; (d) introducing dopant atoms into a predetermined area portion of said thin dielectric film, to induce a significantly increased leakage current therein; (e) providing a gate layer over said capping layer, said gate layer being a thin film conductive layer which is patterned to form the gate electrode of multiple operable insulated-gate field-effect transistors in predetermined locations, other portions of said high-quality thin dielectric film providing the gate dielectric of said transistors, and said monocrystalline semiconductor portions providing the channel of at least some of said transistors; and (f) interconnecting one of said transistors in circuit paths to implement a desired electrical function, wherein some of said circuit paths include current flowing vertically through said increased-leakage-current portions of said high-quality thin film to provide electrical load elements.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein said step (b) grows a film consisting essentially of silicon dioxide.
Claim 4
Dependent Claim
19 words
The process of claim 1, wherein said step (b) is performed at a temperature of about 950 degrees C.
Claim 5
Dependent Claim
22 words
The process of claim 1, wherein said step (c) is performed in a dry atmosphere which includes oxygen and a chlorinating agent.
Claim 6
Dependent Claim
28 words
The process of claim 1, wherein said step (b) grows a film consisting essentially of silicon dioxide, and having a thickness in the range of about 225 Angstroms.
Claim 7
Dependent Claim
16 words
The process of claim 1, wherein said step (b) grows a film consisting of silicon dioxide.
Claim 8
Dependent Claim
25 words
The process of claim 1, further comprising an additional step of growing and removing a sacrificial layer of silicon dioxide, prior to said step (b).
Claim 9
Dependent Claim
15 words
The process of claim 1, wherein said step (b) grows a film comprising silicon oxynitride.
Claim 10
Dependent Claim
16 words
The process of claim 1, wherein said step (b) grows a film comprising a multilayered dielectric.
Claim 11
Dependent Claim
29 words
The process of claim 1, wherein said step (b) grows a film comprising a multilayered dielectric, and at least one layer of said film consists essentially of silicon dioxide.
Claim 12
Dependent Claim
24 words
The process of claim 1, wherein said thin dielectric film comprises a silicon oxynitride, and has an oxygen:nitrogen atomic ratio of at least 4:1.
Claim 13
Dependent Claim
45 words
The process of claim 1, wherein said step (d) of introducing dopant atoms is performed by implantation, with a dosage and energy which provides a maximum concentration of dopant species in said thin dielectric film which is less than about 3×10 21 cm -3 .
Claim 14
Dependent Claim
50 words
The process of claim 1, wherein said step (d) of introducing dopant atoms is performed by implantation, with a dosage and energy which provides an average concentration of dopant species in said thin dielectric film which is in the range of about 10 19 to 10 22 cm -3 inclusive.
Claim 15
Dependent Claim
45 words
The process of claim 1, wherein said step (d) of introducing dopant atoms is performed by implantation, with a dosage and energy which provides an average concentration of dopant species in said thin dielectric film which is greater than about 5×10 20 cm -3 .
Claim 16
Dependent Claim
31 words
The process of claim 1, wherein said step (d) of introducing dopant atoms is performed by implantation, with an area-specific dosage which is less than about 2×10 16 cm -2 .
Claim 17
Dependent Claim
30 words
The process of claim 1, wherein said step (d) of introducing dopant atoms is performed by implantation of a species selected from the group consisting of arsenic, antimony, and gallium.
Claim 18
Dependent Claim
39 words
The process of claim 1, wherein said step (d) of introducing dopant atoms is performed by implantation with an area-specific dosage which is in the range of about 2×10 15 cm -2 to about 1×10 16 cm -2 .
Claim 19
Dependent Claim
58 words
The process of claim 1, wherein said step (d) of introducing dopants is performed by implantation with a dosage and energy which causes said thin dielectric film to have a bulk resistivity (as determined for electric fields of about 150 Volts per micron, and for temperatures in the neighborhood of 25 C.) in the range of 30-10,000 Gigaohm-cm.
Claim 20
Dependent Claim
58 words
The process of claim 1, wherein said step (d) of introducing dopants is performed by implantation with a dosage and energy which causes said thin dielectric film to have a bulk resistivity (as determined for electric fields of about 150 Volts per micron, and for temperatures in the neighborhood of 25 C.) which is less than 10 Teraohm-cm.
Claim 21
Dependent Claim
23 words
The process of claim 1, wherein said step (d) of introducing dopants is performed by implantation of arsenic, followed by implantation of phosphorus.
Claim 22
Dependent Claim
21 words
The process of claim 1, wherein said step (d) of introducing dopants is performed by implantation of two different species separately.
Claim 23
Dependent Claim
32 words
The process of claim 1, further comprising the additional step, after said step (d) and before said step (e), of etching buried contact holes in said thin dielectric film at predetermined locations.
Claim 24
Dependent Claim
20 words
The process of claim 1, wherein said step (c) deposits said capping layer to a thickness of about 500 Ångstroms.
Claim 25
Dependent Claim
21 words
The process of claim 1, wherein, during said step (d), said capping layer is deposited as undoped polysilicon, and then doped.
Claim 26
Dependent Claim
20 words
The process of claim 1, wherein said step (e) provides said gate layer to a thickness of about 4,000 Angstroms.
Claim 27
Dependent Claim
182 words
A process for making an integrated circuit, comprising the steps of: providing a substrate including therein monocrystalline semiconductor portions, consisting predominantly of silicon; growing a high-quality thin dielectric film, consisting predominantly of silicon dioxide, on said monocrystalline semiconductor portions; covering said thin dielectric film with a thin capping layer, said capping layer being polycrystalline and consisting predominantly of silicon; implanting impurities into a predetermined area portion of said thin dielectric film, to induce a significantly increased leakage current therein; providing a gate layer over said capping layer, said gate layer being a thin film conductive layer which is patterned to form the gate electrode of multiple operable insulated-gate field-effect transistors in predetermined locations, other portions of said high-quality thin dielectric film providing the gate dielectric of said transistors, and said monocrystalline semiconductor portions providing the channel of at least some of said transistors; and interconnecting ones of said transistors in circuit paths to implement a desired electrical function, wherein some of said circuit paths include current flowing vertically through said increased-leakage-current portions of said high-quality thin film to provide electrical load elements.
Claim 28
Dependent Claim
182 words
A process for making an integrated circuit, comprising the steps of: providing a substrate including therein monocrystalline semiconductor portions, consisting predominantly of silicon; growing a high-quality thin dielectric film, consisting predominantly of silicon dioxide, on said monocrystalline semiconductor portions; covering said thin dielectric film with a thin capping layer, said capping layer being polycrystalline and consisting predominantly of silicon; implanting impurities into a predetermined area portion of said thin dielectric film, to induce a significantly increased leakage current therein; providing a gate layer over said capping layer, said gate layer being a thin film conductive layer which is patterned to form the gate electrode of multiple operable insulated-gate field-effect transistors in predetermined locations, other portions of said high-quality thin dielectric film providing the gate dielectric of said transistors, and said monocrystalline semiconductor portions providing the channel of at least some of said transistors; and interconnecting ones of said transistors in circuit paths to implement a desired electrical function, wherein some of said circuit paths include current flowing vertically through said increased-leakage-current portions of said high-quality thin film to provide electrical load elements.
Claim 29
Dependent Claim
252 words
A process for making a CMOS integrated-circuit comprising the steps of: (a) providing a body including extended portions of monocrystalline semiconductor material, and including P-type well regions extending to the surface of said body in some respective locations, and N-type regions of said monocrystalline material extending to the surface of said body in other respective locations; (b) forming field isolation regions, said isolation regions defining a plurality of active device regions which are separated from each other by portions of said field isolation regions; (c) growing a high-quality thin dielectric film on said monocrystalline semiconductor portions; (d) covering said thin dielectric film with a thin capping layer; (e) implanting impurities into a predetermined area portion of said thin dielectric film, to induce a significantly increased leakage current therein; (f) providing a gate layer over said capping layer, said gate layer being a thin film conductive layer being patterned to form the gate electrode of multiple operable N-channel insulated-gate field-effect transistors in predetermined locations within said P-type well regions, and of multiple operable P-channel insulated-gate field-effect transitors in predetermined locations within said N-type well regions; (g) introducing a heavy concentration of P-type dopants, with a relatively short stopping distance, into locations of said P-channel transistors; and introducing a heavy concentration of N-type dopants, with a relatively short stopping distance, into locations of said N-channel transistors; and (h) providing at least one pattered thin-film metal layer, which is configured to interconnect one of said transistors in circuit paths to implement a desired electrical function.
Claim 30
Dependent Claim
252 words
A process for making a CMOS integrated-circuit comprising the steps of: (a) providing a body including extended portions of monocrystalline semiconductor material, and including P-type well regions extending to the surface of said body in some respective locations, and N-type regions of said monocrystalline material extending to the surface of said body in other respective locations; (b) forming field isolation regions, said isolation regions defining a plurality of active device regions which are separated from each other by portions of said field isolation regions; (c) growing a high-quality thin dielectric film on said monocrystalline semiconductor portions; (d) covering said thin dielectric film with a thin capping layer; (e) implanting impurities into a predetermined area portion of said thin dielectric film, to induce a significantly increased leakage current therein; (f) providing a gate layer over said capping layer, said gate layer being a thin film conductive layer being patterned to form the gate electrode of multiple operable N-channel insulated-gate field-effect transistors in predetermined locations within said P-type well regions, and of multiple operable P-channel insulated-gate field-effect transitors in predetermined locations within said N-type well regions; (g) introducing a heavy concentration of P-type dopants, with a relatively short stopping distance, into locations of said P-channel transistors; and introducing a heavy concentration of N-type dopants, with a relatively short stopping distance, into locations of said N-channel transistors; and (h) providing at least one pattered thin-film metal layer, which is configured to interconnect one of said transistors in circuit paths to implement a desired electrical function.
References Cited (Backward Citations)
US3922708A
Cited
US4406051A
Cited
EP0122659A2
Cited
US4575923A
Cited
US4755480A
Cited
JPH02549A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-20 | 1994-02-19 | 1994-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-20 | 1998-02-19 | 1998-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-20 | 2002-02-19 | 2002-08-21 | $7700.00 | Window Closed / Lapsed |