Silicon gas injector and method of making

• US 20060185589A1
• Filed: 07/08/2005
• Published: 08/24/2006
• Est. Priority Date: 02/23/2005
• Status: Abandoned Application

• Current Assignee: Integrated Materials, Inc. (Ferrotec Holdings Corporation)
• Original Assignee: Integrated Materials, Inc. (Ferrotec Holdings Corporation)
• Inventors: Reynolds, Reese, Zehavi, Raanan
• Application Number:
  US11/177,808
• Publication Number:
  US 20060185589A1
• Time in Patent Office: Days
• US Class Current: 118/715
• CPC Class Codes: C23C 16/45578 Elongated nozzles, tubes with holes
• CPC Class Codes: C23C 16/4583 the substrate being supported substantially horizontally

Abstract

A gas injector tube usable in a batch thermal treatment oven including two silicon shells joined together with an adhesive formed of a fine silicon powder and a curable silica-forming agent, such as a spin-on glass, which is ultrasonically homogenized. The tube may have a gas outlet on its distal end or be sealed with a silicon cap and have side outlet holes formed along its side. The silicon injector tube may be used in combination with a silicon tower and a silicon liner so that all bulk parts within the furnace hot zone are formed of silicon.

Claims

1. A silicon gas injector comprising an injector tube formed of two shells comprising substantially pure silicon bonded together with an adhesive formed of silicon powder and a silica-forming agent and forming a first central bore therebetween.

2. The injector of claim 1, further comprising a second silicon tube assembly bonded to the two shells with an adhesive formed of silicon powder and a silica-form agent and including a supply tube extending perpendicularly to the injector tube and including a second central bore communicating with the first central bore.

3. The injector of claim 1, wherein the silicon powder has a size distribution with 99% of all particles having diameters of less than 75 μ

m.

4. The injector of claim 3, wherein size distribution has 99% of all the particles having diameters of less than 10 μ

m

5. The injector of claim 4, wherein the size distribution has 99% of all the particles having diameters of less than 100 nm.

6. The injector of claim 2, wherein the second silicon tube assembly includes the supply tube and an elbow formed as an integral unit.

7. The injector of claim 1, wherein the two shells are formed of virgin polysilicon.

8. The injector of claim 1, wherein the two shells comprise mating tongues and grooves at interfaces therebetween.

9. The injector of claim 1, wherein the two shells comprises mating steps at interfaces therebetween.

10. The injector of claim 1, wherein the two shells comprise mating stepped surfaces at interfaces therebetween.

11. The injector of claim 1, further comprising a cap sealed to an end of the bonded shells and further comprising at least one holes formed in an axially extending side of one of the shells and extending to a bore of the tube.

12. The injector of claim 11, wherein there are a plurality of the holes axially spaced along the axially extending side.

13. The injector of claim 12, wherein diameters of the holes or spacings between at least three of the holes varies along the axially extending side.

14. A method of assembling a gas injector, comprising the steps of:

providing two shells comprising substantially pure silicon and forming an axial bore therebetween when assembled together;

applying an adhesive comprising silicon powder and a curable silica-forming agent to at least some mating faces of the two shells;

assembling the two shells by juxtaposing respective mating faces of the two shells; and

annealing the assembled shells at a temperature of at a temperature sufficient to glassify adhesive.

15. The method of claim 14, wherein the temperature is least 400°

C.

16. The method of claim 15, wherein the temperature is between 850 and 1000°

C.

17. The method of claim 14, wherein the providing step includes:

machining the shells from at least one annealed virgin polysilicon member.

18. The method of claim 14, further comprising applying a powder-free wetting agent to at least some of the mating faces prior to applying the adhesive.

19. The method of claim 18, wherein the wetting agent comprises a curable silica-forming agent.

20. The method of claim 14, further comprising:

mixture the silica-forming agent and the silicon powder into a mixture; and

ultrasonically agitating the mixture to form the adhesive.

21. A method of bonding together two silicon parts, comprising the steps of:

mixing together silicon powder and a silica-forming agent;

ultrasonically agitating the mixture;

applying the agitated mixture to at least one of two mating surface of two respective silicon members; and

joining the silicon members along the two mating surfaces with the agitated mixture therebetween.

22. The method of claim 21, further comprising annealing the joined silicon members to thereby cure the silica-forming agent.

23. A method of thermally treating silicon wafers, comprising:

supporting silicon production wafers on a silicon tower;

disposing the silicon tower and the wafers supported thereupon in a furnace including a silicon liner surrounding the tower; and

flowing a process gas through at least one silicon injector having an outlet disposed between the tower and the liner to treat the production wafers in a hot zone of the furnace within the liner;

wherein all bulk portions of the tower, the liner, and the injector disposed within the hot zone are substantially free of material other than silicon and excluding any lead-based adhesive for the injector.

24. The method of claim 23, wherein the injector comprises a tube formed of two substantially pure silicon shells bonded together with an adhesive formed of silicon powder and a silica-forming agent and forming a central axial bore therebetween.