US4874484A
Expired / Lapsed
US
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Etching method for generating apertured openings or trenches in layers or substrates composed of n-doped silicon
Assignee: TDK Electronics AG
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Filing: 1988-05-13
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Granted: 1989-10-17
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Expires: 2008-05-13
Abstract
Abstract The present invention provides the production of apertured openings or trenches in layers or substrates composed of n-doped silicon proceeding in an electrolytic way, whereby the silicon is connected as a positively polarized electrode of an electrolysis cell containing an agent that contains hydrofluoric acid. Hole structures having highly variable cross-section can be reproducibly manufactured with the method of the invention and holes can be localized by prescribing nuclei. The invention can be used in the manufacture of trench cells in memory modules, insulating trenches in LSI semiconductor circuits, large-area capacitors (varicaps), and in contacting more deeply disposed layers in disconnectable and voltage-controlled thyristors.
Inventors
- 👤 Helmut Foell
- 👤 Volker Lehmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:39
CPC Classifications
H; H10; H10D; H10D18/00; H10D18/60; H10D1/00; H10D1/60; H10D1/62; H10D1/64; H10D12/00; H10D12/211; H10D12/212; H10D62/00; H10D62/10; H10D62/17; H10D62/192; H10D62/206; H10D62/343; H10P; H10P50/00; H10P50/60; H10P50/61; H10P50/613
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
90 words
A method for generating apertured openings of trenches in substrates composed of n-silicon, as used in the manufacture of semiconductor components, especially LSI semiconductor circuits, through masked etching, wherein an electrolytic etching is carried out in an electrolyte containing hydrofluoric acid, through the application of a constant or chronologically varying potential, the silicon substrate being connected as a positively polarized electrode of an electrolysis cell, the electrolysis being injected by illuminating the silicon member proceeding from a backside and a structured silicon nitride layer is used as an etching mask.
Claim 2
Independent Claim
90 words
A method for generating apertured openings of trenches in substrates composed of n-silicon, as used in the manufacture of semiconductor components, especially LSI semiconductor circuits, through masked etching, wherein an electrolytic etching is carried out in an electrolyte containing hydrofluoric acid, through the application of a constant or chronologically varying potential, the silicon substrate being connected as a positively polarized electrode of an electrolysis cell, the electrolysis being injected by illuminating the silicon member proceeding from a backside and a structured silicon nitride layer is used as an etching mask.
Claim 3
Independent Claim
91 words
A method for generating apertured openings of trenches in substrates composed of n-silicon, as used in the manufacture of semiconductor components, especially LSI semiconductor circuits, through masked etching, wherein an electrolytic etching is carried out in an electrolyte containing hydrofluoric acid, through the application of a constant or chronologically varying potential, the silicon substrate being connected as a positively polarized electrode of an electrolysis cell, the electrolysis being injected by illuminating the silicon member proceeding from a backside and a chemical etching is also performed before and/or after the electrolytic etching.
Claim 4
Independent Claim
91 words
A method for generating apertured openings of trenches in substrates composed of n-silicon, as used in the manufacture of semiconductor components, especially LSI semiconductor circuits, through masked etching, wherein an electrolytic etching is carried out in an electrolyte containing hydrofluoric acid, through the application of a constant or chronologically varying potential, the silicon substrate being connected as a positively polarized electrode of an electrolysis cell, the electrolysis being injected by illuminating the silicon member proceeding from a backside and a chemical etching is also performed before and/or after the electrolytic etching.
Claim 5
Dependent Claim
16 words
The method of claim 2 wherein the chemical etching is carried out in a caustic solution.
Claim 6
Independent Claim
87 words
A method for generating apertured openings of trenches in substrates composed of n-silicon, as used in the manufacture of semiconductor components, especially LSI semiconductor circuits, through masked etching, wherein an electrolytic etching is carried out in an electrolyte containing hydrofluoric acid, through the application of a constant or chronologically varying potential, the silicon substrate being connected as a positively polarized electrode of an electrolysis cell, the electrolysis being injected by illuminating the silicon member proceeding from a backside and a wetting agent is added to the electrolyte.
Claim 7
Independent Claim
87 words
A method for generating apertured openings of trenches in substrates composed of n-silicon, as used in the manufacture of semiconductor components, especially LSI semiconductor circuits, through masked etching, wherein an electrolytic etching is carried out in an electrolyte containing hydrofluoric acid, through the application of a constant or chronologically varying potential, the silicon substrate being connected as a positively polarized electrode of an electrolysis cell, the electrolysis being injected by illuminating the silicon member proceeding from a backside and a wetting agent is added to the electrolyte.
Claim 8
Dependent Claim
13 words
The method of claim 4 wherein the wetting agent is based on formaldahyde.
Claim 9
Independent Claim
103 words
A method for generating apertured openings of trenches in substrates composed of n-silicon, as used in the manufacture of semiconductor components, especially LSI semiconductor circuits, through masked etching, wherein an electrolytic etching is carried out in an electrolyte containing hydrofluoric acid, through the application of a constant or chronologically varying potential, the silicon substrate being connected as a positively polarized electrode of an electrolysis cell, the electrolysis being injected by illuminating the silicon member proceeding from a backside and a wet etching is carried out in a 1 to about 10 weight percent caustic potash solution with an etching time of 10 minutes.
Claim 10
Independent Claim
103 words
A method for generating apertured openings of trenches in substrates composed of n-silicon, as used in the manufacture of semiconductor components, especially LSI semiconductor circuits, through masked etching, wherein an electrolytic etching is carried out in an electrolyte containing hydrofluoric acid, through the application of a constant or chronologically varying potential, the silicon substrate being connected as a positively polarized electrode of an electrolysis cell, the electrolysis being injected by illuminating the silicon member proceeding from a backside and a wet etching is carried out in a 1 to about 10 weight percent caustic potash solution with an etching time of 10 minutes.
Claim 11
Independent Claim
99 words
A method for generating apertured openings of trenches in substrates composed of n-silicon, as used in the manufacture of semiconductor components, especially LSI semiconductor circuits, through masked etching, wherein an electrolytic etching is carried out in an electrolyte containing hydrofluoric acid, through the application of a constant or chronologically varying potential, the silicon substrate being connected as a positively polarized electrode of an electrolysis cell, the electrolysis being injected by illuminating the silicon member proceeding from a backside and a pre-etching is carried out in a 10 weight percent caustic potash solution with an etching time of 10 minutes.
Claim 12
Independent Claim
99 words
A method for generating apertured openings of trenches in substrates composed of n-silicon, as used in the manufacture of semiconductor components, especially LSI semiconductor circuits, through masked etching, wherein an electrolytic etching is carried out in an electrolyte containing hydrofluoric acid, through the application of a constant or chronologically varying potential, the silicon substrate being connected as a positively polarized electrode of an electrolysis cell, the electrolysis being injected by illuminating the silicon member proceeding from a backside and a pre-etching is carried out in a 10 weight percent caustic potash solution with an etching time of 10 minutes.
Claim 13
Independent Claim
50 words
A method for manufacturing semiconductor components including the steps of generating controlled hole geometries and trenches in a silicon substrate through masked etching by using an electrolytic etching in an electrolyte containing hydrofluoric acid, with a constant or chronologically varying potential, and using a chemical etching before the electrolytic etching.
Claim 14
Independent Claim
50 words
A method for manufacturing semiconductor components including the steps of generating controlled hole geometries and trenches in a silicon substrate through masked etching by using an electrolytic etching in an electrolyte containing hydrofluoric acid, with a constant or chronologically varying potential, and using a chemical etching before the electrolytic etching.
Claim 15
Dependent Claim
17 words
The method of claim 8 including the step of injecting the electrolysis by illuminating the silicon substrate.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-10-16 | 1993-04-17 | 1993-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-16 | 1997-04-17 | 1997-10-17 | $3760.00 | Window Closed / Lapsed |
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