US3800411A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming a stable mnos igfet
Assignee: Northrop Grumman Guidance and Electronics Co Inc
•
Filing: 1972-05-22
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Granted: 1974-04-02
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Expires: 1992-05-22
Abstract
Abstract An MNOS IGFET device is formed by a process that eliminates or substantially minimizes contamination during formation and that results in a stabilized semiconductor device having a high field inversion threshold.
Inventors
- 👤 H Abbink
- 👤 N Goodwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:08
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/69; Y; Y10; Y10S; Y10S148/00; Y10S148/017; Y10S148/053
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
169 words
The method of forming a semiconductor device comprising: a. forming a protective coating on predetermined regions of a substrate surface thereby defining unprotected regions, b. altering the conductivity of the substrate at the unprotected regions, c. removing the protective coating from the substrate surface, d. cleaning the exposed substrate surface, e. growing sequential layers on the clean substrate surface in a controlled environment, the layers including 1. a hysteresis inhibiting layer having a thickness between 100 A and 1000A on the substrate surface, 2. an ion impermeable layer having a thickness between 200 A and 2000 A on the hysteresis inhibiting layer, 3. a protective layer having a thickness between 5000 A and 10,000 A on the ion impermeable layer, and f. forming a plurality of conductive electrodes including 1. a first electrode on one of the altered substrate regions, 2. a second electrode on another of the altered substrate regions, 3. a tHird electrode on the impermeable layer generally between and adjacent to said first and second electrodes.
Claim 2
Independent Claim
169 words
The method of forming a semiconductor device comprising: a. forming a protective coating on predetermined regions of a substrate surface thereby defining unprotected regions, b. altering the conductivity of the substrate at the unprotected regions, c. removing the protective coating from the substrate surface, d. cleaning the exposed substrate surface, e. growing sequential layers on the clean substrate surface in a controlled environment, the layers including 1. a hysteresis inhibiting layer having a thickness between 100 A and 1000A on the substrate surface, 2. an ion impermeable layer having a thickness between 200 A and 2000 A on the hysteresis inhibiting layer, 3. a protective layer having a thickness between 5000 A and 10,000 A on the ion impermeable layer, and f. forming a plurality of conductive electrodes including 1. a first electrode on one of the altered substrate regions, 2. a second electrode on another of the altered substrate regions, 3. a tHird electrode on the impermeable layer generally between and adjacent to said first and second electrodes.
Claim 3
Dependent Claim
18 words
an ion impermeable layer having a thickness between 200 A and 2000 A on the hysteresis inhibiting layer,
Claim 4
Dependent Claim
18 words
an ion impermeable layer having a thickness between 200 A and 2000 A on the hysteresis inhibiting layer,
Claim 5
Dependent Claim
10 words
a second electrode on another of the altered substrate regions,
Claim 6
Dependent Claim
10 words
a second electrode on another of the altered substrate regions,
Claim 7
Dependent Claim
14 words
The method of claim 1 in which said hysteresis inhibiting layer is silicon dioxide.
Claim 8
Dependent Claim
20 words
The method of claim 2 in which said growing of said layer is by the oxidation of a silicon substrate.
Claim 9
Dependent Claim
17 words
a tHird electrode on the impermeable layer generally between and adjacent to said first and second electrodes.
Claim 10
Dependent Claim
17 words
a tHird electrode on the impermeable layer generally between and adjacent to said first and second electrodes.
Claim 11
Dependent Claim
27 words
a protective layer having a thickness between 5000 A and 10, 000 A on the ion impermeable layer, and f. forming a plurality of conductive electrodes including
Claim 12
Dependent Claim
27 words
a protective layer having a thickness between 5000 A and 10, 000 A on the ion impermeable layer, and f. forming a plurality of conductive electrodes including
Claim 13
Dependent Claim
13 words
The method of claim 1 in which said ion-impermeable layer is silicon nitride.
Claim 14
Dependent Claim
19 words
The method of claim 4 in which said growing of said ion-impermeable layer is by the ammonization of silane.
Claim 15
Dependent Claim
13 words
The method of claim 1 in which said protective layer is silicon dioxide.
Claim 16
Dependent Claim
19 words
The method of claim 6 in which said growing of said protective layer is by the oxidation of silane.
Claim 17
Dependent Claim
32 words
The method of claim 1 in which said growing of said hysteresis inhibiting layer and of said ion-impermeable layer is sequentially completed in a controlled atmosphere furnace without exposure to the ambient.
Claim 18
Dependent Claim
28 words
The method of claim 1 in which respective ones of said first and second electrodes are source and drain electrodes and said third electrode is a gate electrode.
Claim 19
Dependent Claim
15 words
The method of claim 1 in which said protective coating is a temporary oxide layer.
Claim 20
Dependent Claim
20 words
The method of claim 1 in which said ion-impermeable layer has a dielectric constant greater than said hysteresis inhibiting layer.
Claim 21
Dependent Claim
14 words
The method of claim 1 in which cleaning said exposed substrate surface eliminates contaminants.
Claim 22
Dependent Claim
11 words
The method of claim 12 in which said contaminants include oxide.
Claim 23
Independent Claim
178 words
The method of forming a semiconductor device comprising: a. growing a protective oxide layer on a silicon substrate, b. opening windows through said protective oxide layer at predetermined regions to expose the substrate, c. diffusing a suitable dopant through the windows into the exposed substrate to form altered areas in the substrate, d. stripping the protective oxide layer from the silicon substrate, e. cleaning the stripped and exposed substrate surface, f. growing a hysteresis inhibiting oxide layer having a thickness between 100 and 1,000 A. on the clean substrate surface, g. depositing an ion-impermeable silicon nitride layer having a thickness between 200 and 2,000 A. on the hysteresis inhibiting oxide layer, h. depositing a protective silicon dioxide layer having a thickness between 5,000 and 10,000 A. on the silicon nitride layer, i. opening at least a first window in the silicon dioxide layer at a predetermined region to expose the silicon nitride layer, j. depositing a metal layer at said window opening, and k. photoetching the resulting metal layer to form an electrode having a selected electrical characteristic.
Claim 24
Independent Claim
178 words
The method of forming a semiconductor device comprising: a. growing a protective oxide layer on a silicon substrate, b. opening windows through said protective oxide layer at predetermined regions to expose the substrate, c. diffusing a suitable dopant through the windows into the exposed substrate to form altered areas in the substrate, d. stripping the protective oxide layer from the silicon substrate, e. cleaning the stripped and exposed substrate surface, f. growing a hysteresis inhibiting oxide layer having a thickness between 100 and 1,000 A. on the clean substrate surface, g. depositing an ion-impermeable silicon nitride layer having a thickness between 200 and 2,000 A. on the hysteresis inhibiting oxide layer, h. depositing a protective silicon dioxide layer having a thickness between 5,000 and 10,000 A. on the silicon nitride layer, i. opening at least a first window in the silicon dioxide layer at a predetermined region to expose the silicon nitride layer, j. depositing a metal layer at said window opening, and k. photoetching the resulting metal layer to form an electrode having a selected electrical characteristic.
Claim 25
Dependent Claim
57 words
The method of claim 14 in which the step of opening at least a first window further includes opening a plurality of windows to expose said altered substrate areas, depositing the metal layer at said window openings, and photoetching the metal layer to form a plurality of electrodes having selected electrical characteristics of gate, source, and drain.
References Cited (Backward Citations)
US3724065A
Cited
US3707656A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |