US4764249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing a coating layer for semiconductor technology and also use of the coating layer
Assignee: BBC BROWN BOVERI Ltd
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Filing: 1987-03-16
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Granted: 1988-08-16
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Expires: 2007-03-16
Abstract
Abstract A coating layer (2) for semiconductor technology having an edge contour which has a wedge-shaped cross section is produced by predominantly anisotropic dry etching of the coating layer (2) through a mask (4) disposed in front of the coating layer (2) at a finite mask distance (A). The coating layer (2) etched in this manner is especially well suited as an insulating substrate for a field plate in the edge region of a P-N junction emerging at the surface and also as implantation mask for producing a P-N junction with lateral doping gradients.
Inventors
- 👤 Jens Gobrecht
- 👤 Jan Voboril
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:07
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/69; H10P50/691; H10P50/693; H10D; H10D30/00; H10D30/60; H10D30/64; H10D30/66; H10D30/668; H10D62/00; H10D62/10; H10D62/102; H10D62/103; H10D62/105; H10D64/00; H10D64/111
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
87 words
A method of producing a coating layer with apertures on a semiconductor substrate, whereby said apertures have wedge-shaped edges, said method comprising the steps of: covering said semiconductor substrate with a uniform coating layer; fabricating a mask with apertures which corresponds to said apertures to be produced in said coating layer; disposing said mask at a mask distance of between 1 and 10 mm above said coating layer; and etching said coating layer apertures through said mask apertures by means of a predominantly anisotropical dry etching method.
Claim 2
Independent Claim
87 words
A method of producing a coating layer with apertures on a semiconductor substrate, whereby said apertures have wedge-shaped edges, said method comprising the steps of: covering said semiconductor substrate with a uniform coating layer; fabricating a mask with apertures which corresponds to said apertures to be produced in said coating layer; disposing said mask at a mask distance of between 1 and 10 mm above said coating layer; and etching said coating layer apertures through said mask apertures by means of a predominantly anisotropical dry etching method.
Claim 3
Dependent Claim
17 words
The method as claimed in claim 1, wherein said dry etching method is a plasma etching method.
Claim 4
Dependent Claim
31 words
The method as claimed in claim 2, wherein the coating layer (2) consists of SiO 2 or Si 3 N 4 and an SF 6 plasma is used for the etching.
Claim 5
Dependent Claim
28 words
The method as claimed in claim 2, wherein the coating layer (2) consists of a photoresist or another polymer and an oxygen-containing plasma is used for the etching.
Claim 6
Dependent Claim
43 words
The method as claimed in claim 3, wherein the etching is carried out at a pressure of about 20 μbar, a gas flow of about 5 standard ccm, and HF power of about 150 W and an autopolarization voltage of about 800 V.
Claim 7
Dependent Claim
26 words
The method as claimed in claim 2, wherein a plasma consisting of a mixture of oxygen and a halogenated hydrocarbon is used for the etching step.
Claim 8
Dependent Claim
17 words
The method as claimed in claim 2, wherein a halogen gas plasma is used for the etching.
Claim 9
Dependent Claim
50 words
The use of a coating layer produced by the method as claimed in claim 1 as a mask in a masked doping process, in particular as implantation mask in ion implantation for producing a lateral doping gradient in the edge region of a planar, high reverse voltage P-N junction (10).
Claim 10
Dependent Claim
32 words
The method as claimed in claim 1, wherein a mechanical mask which maintains the mask distance (A) over the entire mask area from the coating layer (2) is used as mask (4).
Claim 11
Dependent Claim
41 words
The method as claimed in claim 1, wherein an overhang (9), which is removed from the coating layer (2) by the mask distance (A), in the opening of a covering (6) adjacent to the coating layer (2) is used as mask.
Claim 12
Dependent Claim
41 words
The use of a coating layer produced by the method as claimed in claim 1 as an insulating substrate for a field plate (7) lying at an angle in the edge region of a planar, high reverse voltage P-N junction (10).
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) | 1991-08-16 | 1992-02-15 | 1992-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-16 | 1996-02-15 | 1996-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-16 | 2000-02-15 | 2000-08-16 | $7700.00 | Window Closed / Lapsed |