Quartz lamp heater assembly for thin film deposition apparatus

• US 5,781,692 A
• Filed: 06/04/1997
• Issued: 07/14/1998
• Est. Priority Date: 06/04/1997
• Status: Expired due to Fees

• Current Assignee: Northrop Grumman Corporation
• Original Assignee: TRW Inc. (Northrop Grumman Corporation)
• Inventors: Wagner, Mark K.
• Primary Examiner(s): Jeffery, John A.
• Application Number:
  US08/855,545
• Time in Patent Office: 405 Days
• Field of Search: 392/411, 392/415, 392/416, 392/418, 392/407, 392/408, 219/553, 219/411, 219/537, 219/541, 250/504 R, 362/218, 362/227, 362/249, 439/235, 118/724, 118/725
• US Class Current: 392/411
• CPC Class Codes: C23C 14/541 Heating or cooling of the substrates
• CPC Class Codes: H05B 3/0038 for industrial applications

Abstract

A heater assembly for a vapor deposition apparatus is able to achieve extended operating life in the Oxygen rich low pressure high temperature atmosphere even though employing commercially available quartz lamps to generate heat. Multiple quartz lamps (1) are individually held in a socket-less support (3). The rigid lamp terminals (22 & 24) are connected to respective lengths of flexible stranded wire (30 & 28) by an INCONEL crimp insert (32 & 34), forming cables through which the lamp is connected in electrical circuit and that effectively isolate the lamp terminals from the physical effects of relative thermal expansion between heater assembly elements.

Claims

1. A heater assembly for a vapor deposition apparatus comprising:

a plurality of quartz lamps;

said lamps comprising a gas proof light transmissive envelope confining a xenon gas and a tungsten filament, and containing at least a pair of electrical conductors extending through said gas proof envelope in gas sealed relationship therewith, said conductors being connected electrically, internal of said envelope, to opposite ends of said tungsten filament;

a first elongate electrical lead, comprising a flexible stranded electrical wire;

a second elongate electrical lead, shorter than said first, comprising a flexible stranded electrical wire;

a pair of Inconel crimping sleeves;

said first Inconel crimping sleeve engaging an end of said first elongate electrical lead and an end of said lamp electrical conductor for crimping said leads together, wherein said first elongate electrical lead is pressed into direct contact with said lamp electrical lead;

said second Inconel crimping sleeve engaging an end of said second elongate electrical lead and an end of said second lamp electrical conductor for crimping said leads together, wherein said second elongate electrical lead is pressed into direct contact with said lamp electrical lead to provide an oxidizing atmosphere resistant electrical contact;

first and second fiberglass sleeves for providing electrical insulation over said respective conductors and electrical leads;

a terminal connector member on the remaining end of said first lead, and another terminal connector member on the remaining end of said second elongated electrical lead;

metal lamp support means;

said lamp support means comprising a hollow cylindrical member having an axis, and a disk shaped end wall portion at a front end, said end wall portion having a radiant energy reflecting surface, and having a plurality of lamp receiving cylindrical openings through said end wall portion, said plurality being equal in number to the number of lamps in said plurality of lamps;

said openings being symmetrically positioned in said front wall portion, evenly angularly spaced about said axis at a predetermined radial distance therefrom;

first and second semi-cylindrical insert members, said cylindrical portion being of a diameter adapted to fit within and conform to the cylindrical wall of said lamp opening, and each said insert member having a flat end for engaging a portion of said lamp;

said insert members being positioned on each side of said lamp envelope and within said lamp opening with the flat side of said insert member engaging said lamp envelope;

said lamp housing member having an annular metal member coaxially positioned on said rear surface;

a plurality of terminal fastening means extending from said annular member, said terminal fastening means being symmetrically positioned about said annulus;

said terminals of said second electrical lead of each lamp means being fastened to a respective one of said terminal fastening means to place one terminal of each of said lamp means in common electrical circuit;

a first hollow metal shaft of diameter D1;

said hollow metal shaft having an end engaging said annular metal member for supporting said lamp housing member in cantilever like fashion;

a second hollow support shaft of diameter D2, said second support shaft being located within said hollow rotatable metal shaft and coaxial therewith;

a third hollow support shaft of diameter D3, said third shaft ensleeving a portion of said first hollow metal shaft to leave an end portion of said first hollow metal shaft exposed and being oriented coaxial with said first shaft to define a annular cylindrical space between said first and third shafts;

bearing means located within said annular cylindrical space for rotatably supporting said third rotatable metal shaft on said first hollow metal shaft;

a hollow cylindrical spool-shaped electrical insulator of predetermined length, said cylindrical spool-shaped insulator being mounted on an exposed portion of said first hollow shaft;

first and second semi-cylindrical metal clam-shell members adapted to be fastened together to define a cylindrical metal member;

first fastening means for fastening said semi-cylindrical members together over said hollow cylindrical spool-shaped insulator;

second terminal fastening means for fastening each of said terminal means of said first elongate lead of each of said quartz lamps to said cylindrical metal member;

axially extending passage means through one of said clam shell members;

stranded electrical conductor means extending through said axially extending passage means in said one clam shell member, said stranded electrical conductor means extending along side said third shaft means; and

thermocouple means mounted in said lamp housing member.

2. The invention as defined in claim 1 wherein said stranded electrical conductor means further includes a fused end, said fused end being positioned at an end of said axially extending passage means in said one clam shell member.

3. The invention as defined in claim 2, further comprising radially extending passage means in said one clam shell member, said radially extending passage means intersecting said axially extending passage means in said clam shell member;

copper crush button disposed in said radially extending passage means and abutting a side of said stranded electrical conductor means.

4. The invention as defined in claim 3 wherein said terminal fastening means further comprises:

a threaded member, said threaded member being axially extending, and a nut for fastening to said threaded member, wherein said terminal means is placed in compressed engagement between said nut and said annular member; and

wherein said invention further comprises;

first coolant connector means coupled to one of said second and third shafts for introducing coolant fluid to the hollow of said third hollow metal shaft; and

second coolant connector means for coupling coolant from the annular space between said second hollow support shaft and said third hollow support shaft to an external coolant fluid sink.

5. An electrical heater assembly for disposition within a high temperature oxidizing environment in a vapor film deposition apparatus to maintain a deposited film within said vapor film deposition apparatus at a temperature within the range of 650 degrees Centigrade to 900 degrees Centigrade, comprising:

a plurality of quartz lamps, each said lamps containing a glass envelope confining a gas atmosphere and a coiled Tungsten filament, and first and second elongate relatively rigid electrical contacts extending from said glass envelope;

a lamp housing assembly for holding said plurality of quartz lamps in position about a front side of said housing assembly for radiating heat from said front side of said housing assembly;

said lamp housing assembly containing a plurality of passages between said front side and said rear side, each said passage for holding a respective one of said quartz lamps with at least a major portion of said quartz lamp'"'"'s glass envelope extending through said front side of said lamp housing assembly;

a first elongate hollow metal shaft;

said first elongate hollow metal shaft for providing a cantilever support for said lamp housing assembly and providing an internal conduit for passage of coolant fluid;

a first hollow metal cylinder, said first hollow metal cylinder being supported upon said first elongate metal shaft and electrically insulated therefrom, said first hollow metal cylinder being oriented coaxial with said first metal shaft and surrounding a portion thereof;

a second hollow short metal cylinder, said second hollow short metal cylinder being mounted to a rear side of said lamp housing assembly oriented coaxial with said first elongate metal shaft and being in electrical contact with said first elongate metal shaft;

and wherein each of said plurality of quartz lamps includes associated therewith;

a first length of relatively flexible stranded wire;

a second length of relatively flexible stranded wire;

said second length being shorter in length than said first length;

and first and second crimp inserts, each of said crimp inserts being formed of a metal material that is non-corroding by Oxygen;

said first length of wire having an end connected to said first hollow metal cylinder; and

said first crimp insert mechanically and electrically connecting a remaining end of said first length of wire to a first one of said quartz lamp'"'"'s elongate rigid electrical contacts;

and said second length of wire having an end connected to said second hollow metal cylinder; and

said second crimp insert mechanically and electrically connecting a remaining end of said second length of wire to a second one of said quartz lamp'"'"'s elongate rigid electrical contacts;

whereby said quartz lamps are placed in a parallel electric circuit between said first hollow metal cylinder and said second hollow short metal cylinder;

electrical lead means extending alongside said first elongate hollow metal shaft to maintain close proximity to said internal conduit of said first elongate hollow metal shaft, whereby said electrical lead means is cooled;

said electrical lead means extending into electrical contact with said first hollow metal cylinder to complete a series electrical circuit through said first hollow metal cylinder, said parallel electrical circuit through said plurality of quartz lamps, said second hollow short metal cylinder and said first elongate hollow metal shaft.

6. The invention as defined in claim 5, wherein said metal material comprises INCONEL.

7. The invention as defined in claim 5, wherein lamp housing assembly holds said quartz lamps in a planar array with said lamps being symmetrically positioned about a center of said front side.

8. The invention as defined in claim 5, wherein said heater assembly further includes:

first fastening means for each said first length of wire for connecting said end of said first length of wire to said first hollow metal cylinder, each said first fastening means comprising;

a first connecting ring connected to said end of said first wire;

said first hollow metal cylinder including a threaded bolt hole associated with said connecting ring; and

bolt means extending through said first connecting ring and into said first hollow metal cylinder for holding said connecting ring in mechanical and electrical contact with said first hollow metal cylinder;

a second fastening means for each said second length of wire for connecting said end of said second length of wire to said second hollow short metal cylinder, each said second fastening means comprising;

a second connecting ring connected to said end of said second wire;

said second hollow short metal cylinder containing a threaded stud;

said second connecting ring extending onto said threaded stud; and

nut means threaded onto said threaded stud for holding said connecting ring in mechanical and electrical contact with said second hollow short metal cylinder;

and wherein said first hollow metal cylinder includes a first axially extending passage, and wherein said electrical lead means extends into said first axially extending passage.

9. The invention as defined in claim 8, wherein each of said plurality of quartz lamps further includes associated therewith:

a first sleeve of fiberglass insulating material ensleeving said first rigid electrical contact, crimp insert, and said first length of wire; and

Et second sleeve of fiberglass insulating material ensleeving said second rigid electrical contact, said crimp insert, and said second length of wire.

10. The invention as defined in claim 5, further comprising:

a spool of electrical insulating material;

said spool being mounted upon said first elongate hollow metal shaft; and

wherein said first hollow metal cylinder seats coaxially upon said spool.

11. The invention as defined in claim 5, wherein said lamp housing assembly includes an internal cavity for circulating coolant fluid;

wherein said first hollow metal shaft includes an end that opens into said internal cavity of said lamp housing assembly and, further comprising;

a second hollow metal shaft for internally providing a second coolant conduit to said lamp housing assembly, said second hollow metal shaft being mounted within said first hollow metal shaft and oriented coaxial therewith, said second hollow metal shaft having an end opening into said internal cavity of said lamp housing assembly.

12. The invention as defined in claim 11, further comprising:

a third elongate hollow metal shaft, said third hollow elongate metal shaft being mounted coaxially over a portion of said first hollow metal shaft and being axially rotatable relative to said first hollow metal shaft;

a disk shaped metal member containing a central circular shaped opening;

clamping means, said clamping means being supported on said third elongate metal shaft for supporting said disk shaped metal member coaxial with said first hollow metal shaft in a position with said central circular opening overlying said first hollow metal cylinder, and said disk shaped metal member being in spaced relation to said first hollow metal shaft.

13. The invention as defined in claim 12, further comprising:

Bearing means;

said bearing means being supported by said first hollow metal shaft for mounting said third hollow metal shaft for rotation about axial rotation.

14. The invention as defined in claim 13, wherein said lamp housing assembly further comprises a cylindrical exterior surface.

15. The invention as defined in claim 14, further comprising:

first fluid coupling means for coupling coolant fluid into said second hollow metal shaft;

second fluid coupling means for expressing coolant fluid from said first hollow metal shaft;

means for connecting a DC current source to said electrical lead means; and

means for connecting said first hollow metal shaft to electrical ground.