US4941942A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing a mask support of sic for x-ray lithography masks
Assignee: US Philips Corp
•
Filing: 1988-09-29
•
Granted: 1990-07-17
•
Expires: 2008-09-29
Abstract
Abstract A method of manufacturing a mask support or diaphragm of SiC for X-ray lithography masks is set forth in which a SiC layer is deposited by means of chemical vapor deposition (CVD) on a substrate in the form of a monocrystalline silicon wafer on at least one of the two major surfaces of the monocrystalline silicon wafer, after which the monocrystalline silicon wafer is removed except an edge region in a selective etching step. According to the invention the following processing steps are used: (a) deposition of the SiC layer with the monocrystalline silicon wafer first being heated in the apparatus provided for the deposition process to a temperature in the range of 1000 DEG to 1350 DEG C. in a H2 atmosphere and then being etched by a suitable etchant and subsequently being rinsed under the influence of H2, whereupon the SiC layer is provided from a gas atmosphere containing silicon and hydrocarbons, after which the coated substrate is cooled in a H2 atmosphere to ambient temperature, and (b) implantation of ions into the SiC layer for mechanically disturbing the crystal structure of the SiC layer.
Inventors
- 👤 Angelika M. Bruns
- 👤 Margret Harms
- 👤 Holger K. G. Luthje
- 👤 Bernd Matthiessen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:09
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/22
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
174 words
A method of manufacturing a mask support or membrane of SiC for X-ray lithography masks comprising the steps of (a) heating a monocrystalline silicon wafer to a temperture in the range of from 1000° to 1350° C. in a H 2 atmosphere, said monocrystalline silicon wafer having two major surfaces, (b) then etching the heatd monocrystalline silicon wafer and subsequently rinsing the etched monocrystalline silicon wafer under the influence of H 2 , (c) depositing a layer of SiC on the rinsed monocrystalline silicon wafer in a gas atmosphere of silicon and hydrocarbons, said layer of SiC coating at least one of said two major surfaces of said monocrystalline silicon wafer, (d) cooling the coated monocrystalline silicon wafer to ambient temperature in a H 2 atmosphere, (e) implanting ions into said layer of SiC for mechanically disturbing the crystal structure of said layer of SiC, and (f) selectively removing said monocrystalline silicon from said layer of SiC except at edges of said monocrystalline silicon wafer, thereby exposing both sides of said layer of SiC.
Claim 2
Independent Claim
174 words
A method of manufacturing a mask support or membrane of SiC for X-ray lithography masks comprising the steps of (a) heating a monocrystalline silicon wafer to a temperture in the range of from 1000° to 1350° C. in a H 2 atmosphere, said monocrystalline silicon wafer having two major surfaces, (b) then etching the heatd monocrystalline silicon wafer and subsequently rinsing the etched monocrystalline silicon wafer under the influence of H 2 , (c) depositing a layer of SiC on the rinsed monocrystalline silicon wafer in a gas atmosphere of silicon and hydrocarbons, said layer of SiC coating at least one of said two major surfaces of said monocrystalline silicon wafer, (d) cooling the coated monocrystalline silicon wafer to ambient temperature in a H 2 atmosphere, (e) implanting ions into said layer of SiC for mechanically disturbing the crystal structure of said layer of SiC, and (f) selectively removing said monocrystalline silicon from said layer of SiC except at edges of said monocrystalline silicon wafer, thereby exposing both sides of said layer of SiC.
Claim 3
Dependent Claim
90 words
A method according to claim 1, wherein said step (c) is carried out by depositing said layer of SiC on both of said two major surfaces, and wherein said step (f) is carried out by first removing a portion of said layer of SiC from one of said two major surfaces to thereby expose a part of said monocrystalline silicon wafer, and then selectively etching said part of said monocrystalline silicon wafer through to the other of said two major surfaces to expose both sides of said layer of SiC.
Claim 4
Independent Claim
27 words
A method according to claims 1 or 2, wherein said step (a) is carried out by heating said monocrystalline silicon wafer to a temperature of 1110° C.
Claim 5
Independent Claim
53 words
A method according to claims 1 or 2, wherein said step (c) is carried out by using in said gas atmosphere 0.05 to 8.0% of dichlorodimethyl silane, (CH 3 ) 2 Si, Cl 2 , in hydrogen, H 2 , and 15% of propane, C 3 H 8 , related to dichlorodimethyl silane.
Claim 6
Dependent Claim
14 words
A method according to claim 4, wherein 1.4% of said dichlorodimethyl silane is used.
Claim 7
Dependent Claim
23 words
A method according to claim 4, wherein during said step (c) said layer of SiC is deposited to a thickness of 2.5 μm.
Claim 8
Dependent Claim
46 words
A method according to claim 6, wherein said step (e) is carried out by implanting boron ions into said layer of SiC at a dose of 10 15 to 10 16 cm/ 2 at an implantation energy in the range of from 150 to 400 keV.
Claim 9
Dependent Claim
27 words
A method according to claim 7, wherein said boron ions are implanted at a dose of 10 16 /cm 2 at an implantation energy of 170 keV.
Claim 10
Dependent Claim
46 words
A method according to claim 6, wherein said step (e) is carried out by implanting carbon ions into said layer of SiC at a dose of 10 15 to 5×10 16 /cm 2 at an implantation energy in the range of from 150 to 400 keV.
Claim 11
Dependent Claim
27 words
A method according to claim 9, wherein said carbon ions are implanted at a dose of 10 16 /cm 2 at an implantation energy of 400 keV.
Claim 12
Dependent Claim
45 words
A method according to claim 6, wherein said step (e) is carried out by implanting nitrogen ions into said layer of SiC at a dose of 10 15 to 5×10 16 /cm 2 at an implantation energy in the rangeof from 150 to 400 keV.
Claim 13
Dependent Claim
27 words
A method according to claim 11, wherein said nitrogen ions are implanted at a dose of 2×10 16 /cm 2 at an implantation energy of 400 keV.
Claim 14
Independent Claim
32 words
A method according to claims 1 or 2, wherein said step (c) is carried out by using silane, SiH 4 , with toluene, C 7 H 8 , in said gas atmosphere.
Claim 15
Independent Claim
32 words
A method according to claims 1 or 2, wherein said step (c) is carried out by using silane, SiH 4 , with propane, C 3 H 8 , in said gas atmosphere.
Claim 16
Dependent Claim
25 words
A method according to claim 4, wherein said step (a) is carried out by heating said monocrystalline silicon wafer to a temperature of 1110° C.
Claim 17
Dependent Claim
25 words
A method according to claim 14, wherein said step (a) is carried out by heating said monocrystalline silicon wafer to a temperature of 1110° C.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-16 | 1994-01-15 | 1994-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-16 | 1998-01-15 | 1998-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-16 | 2002-01-15 | 2002-07-17 | $7700.00 | Window Closed / Lapsed |