US5279703A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the thin etching of substrates
Assignee: Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung eV
•
Filing: 1991-06-27
•
Granted: 1994-01-18
•
Expires: 2011-06-27
Abstract
Abstract In a process for the thin etching of substrates which are adapted to be etched by chemical etching agents, a predeterminable substrate layer thickness is obtained with an unaffected single-crystal grid structure of the substrate in that the substrate is irradiated during the etching process by means of a radiation source whose radiation impinges substantially perpendicularly to the substrate surface, the substrate consists of a radiation-absorbent material and the wavelength of the main component of the radiation is chosen such that the absorption length of the radiation of this wavelength in this substrate material is greater than the desired substrate layer thickness.
Inventors
- 👤 Karl Haberger
- 👤 Reinhold Buchner
- 👤 Dieter Bollmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:26
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; H10P90/126; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/644; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10W; H10W10/00; H10W10/10; H10W10/181
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
87 words
A process for the thin-etching to a desired substrate layer thickness of substrates that are etched by contact with chemical etching agents, comprising the steps of: selecting a substrate consisting of a radiation-absorbent material; selecting a radiation source that emits radiation having an absorption length in the radiation-absorbent substrate greater than the desired substrate layer thickness; and irradiating the substrate with the emitted radiation from the radiation source, wherein the emitted radiation impinges on the substrate at an angle substantially perpendicularly to a surface of the substrate.
Claim 2
Dependent Claim
87 words
A process for the thin-etching to a desired substrate layer thickness of substrates that are etched by contact with chemical etching agents, comprising the steps of: selecting a substrate consisting of a radiation-absorbent material; selecting a radiation source that emits radiation having an absorption length in the radiation-absorbent substrate greater than the desired substrate layer thickness; and irradiating the substrate with the emitted radiation from the radiation source, wherein the emitted radiation impinges on the substrate at an angle substantially perpendicularly to a surface of the substrate.
Claim 3
Dependent Claim
48 words
A process according to claim 1, wherein the radiation-absorbent substrate is part of a wafer-bonding-SOI substrate, which wafer-bonding-SOI substrate comprises a carrier layer, an insulating layer arranged on said carrier layer, and a usable layer arranged on said insulating layer; and the radiation-absorbent substrate is the usable layer.
Claim 4
Dependent Claim
14 words
A process according to claim 2, wherein the carrier layer comprises a semiconductor material.
Claim 5
Dependent Claim
21 words
A process according to claim 2, wherein the carrier layer comprises a material which substantially does not absorb the emitted radiation.
Claim 6
Dependent Claim
21 words
A process according to claim 4, wherein the carrier layer comprises a material which is transparent in the visible wavelength region.
Claim 7
Dependent Claim
13 words
A process according to claim 5, wherein the carrier layer comprises quartz glass.
Claim 8
Dependent Claim
29 words
A process according to claim 1, wherein the absorption length of the emitted radiation in the radiation-absorbent substrate is between three and eight times the desired substrate layer thickness.
Claim 9
Dependent Claim
13 words
A process according to claim 1, wherein the emitted radiation is monochromatic light.
Claim 10
Dependent Claim
15 words
A process according to claim 1, wherein the emitted radiation is a thermal, non-monochromatic radiation.
Claim 11
Dependent Claim
22 words
A process according to claim 1, wherein the irradiating step comprises irradiating different areas of the substrate with radiations of different wavelengths.
Claim 12
Dependent Claim
23 words
A process according to claim 1, wherein the irradiating step comprises irradiating different areas of the substrate with radiations of different power densities.
Claim 13
Dependent Claim
33 words
A process according to claim 1, wherein the irradiating step comprises irradiating different areas of the substrate sequentially with radiations of different wavelengths and each area is irradiated with radiation of one wavelength.
Claim 14
Dependent Claim
23 words
A process according to claim 1, wherein the chemical etching agent is selected from the group consisting of a liquid and a gas.
References Cited (Backward Citations)
US2841477A
Cited
US3830665A
Cited
DE2951938A1
Cited
US4518456A
Cited
US4678536A
Cited
US4838989A
Cited
US4861421A
Cited
JPH0244730A
Cited
JPH0244729A
Cited
JPH0244728A
Cited
US5057184A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-17 | 1997-07-19 | 1998-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-17 | 2001-07-19 | 2002-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-17 | 2005-07-19 | 2006-01-18 | $7700.00 | Window Closed / Lapsed |