Adhesive of a silicon and silica composite for bonding together silicon parts

• US 20060213601A1
• Filed: 06/01/2006
• Published: 09/28/2006
• Est. Priority Date: 04/23/2003
• Status: Active Grant

• Current Assignee: Hangzhou Dunyuanjuxin Semiconductor Technology Company Limited
• Original Assignee: Amnon Chalzel, James E. Boyle, Raanan Zehavi
• Inventors: Boyle, James E., Zehavi, Raanan, Chalzel, Amnon
• Granted Patent: US 7,666,513 B2
• Time in Patent Office: Days
• US Class Current: 156/89.110
• CPC Class Codes: H01L 21/67306 characterized by a material, a roughness, a coating or the like
• CPC Class Codes: Y10T 428/24174 including sheet or component perpendicular to plane of web or sheet
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/252 Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension

Abstract

A method of joining two silicon members, the adhesive used for the method, and the joined product, especially a silicon tower for supporting multiple silicon wafers. A flowable adhesive is prepared comprising silicon particles of size less than 100 μm and preferably less than 100 nm and a silica bridging agent, such as a spin-on glass. Nano-silicon crystallites of about 20 nm size may be formed by CVD. Larger particles may be milled from virgin polysilicon. If necessary, a retardant such as a heavy, preferably water-insoluble alcohol such as terpineol is added to slow setting of the adhesive at room temperature. The mixture is applied to the joining areas. The silicon parts are assembled and annealed at a temperature sufficient to link the silica, preferably at 900° C. to 1100° C. for nano-silicon but higher for milled silicon.

Claims

1. A joined silicon assembly, comprising:

at least two silicon parts juxtaposed across respective pairs of joining areas separated by respective gaps; and

a composite bridging the gaps and comprising silicon crystallites having sizes of less than 100 μ

m embedded in a matrix of silica.

2. The assembly of claim 1, wherein the crystallites have a size distribution with at least 99% of particles of size of less than 100 nm.

3. The assembly of claim 1 configured as a support fixture for supporting a plurality of substrates in parallel orientations spaced along an axis of the fixture.

4. The assembly of claim 1, wherein the silicon parts consist essentially of silicon.

5. A substrate support fixture, comprising:

a plurality of silicon legs including teeth for supporting a plurality of substrate in parallel orientations;

two silicon bases joined to opposing ends of the legs across respective joints with respective gaps between a respective one of the bases and a respective one of the legs;

silicon crystallites having sizes of less than 100 μ

m occupying at least 50% of the gaps; and

a silica network in each of the gaps joining the silicon crystallites and the legs and the bases.

6. The fixture of claim 5, wherein the sizes are between 1 and 75 μ

m.

7. The fixture of claim 5, wherein the silicon crystallites have a size distribution with at least 99% of particles having a size of less than 100 nm.

8. The fixture of claim 5, wherein the legs comprise an arcuate back side opposite the tips of the teeth supporting the substrates.

9. An adhesive for joining two parts, comprising a mixture flowable at a room-temperature application temperature and composed of:

silicon particles having sizes of less than 100 μ

m; and

a silica bridging agent in which the particles are dispersed and which chemically reacts to form a silica network when annealed at an elevated temperature above the application temperature.

10. The adhesive of claim 9, wherein the silica bridging agent is a silicon-containing material.

11. The adhesive of claim 9, wherein the silica bridging agent is a spin-on glass.

12. The adhesive of claim 9, wherein 99% of the particles have a size of less than 100 nm.

13. The adhesive of claim 9, wherein the particles have size distribution with a median size in a range of 10 to 25 nm.

14. A silicon assembly comprising at least two silicon parts bonded together along respective joining areas by the method of:

providing a mixture of a powder consisting essentially of silicon and a chemical which when annealed to an annealing temperature vitrifies to form a silicate glass;

applying the mixture to at least one of the joining areas;

assembling the at least two silicon parts with the respective joining areas in juxtaposition; and

annealing the assembled parts at the annealing temperature to thereby bond the parts together.

15. The assembly of claim 14, wherein the at least two silicon parts include two silicon bases and at least three silicon legs bonded on ends thereof to the silicon bases and including teeth formed therein for supporting a plurality of substrates in a stacked arrangement.

16. The assembly of claim 14, wherein the silicon parts consist essentially of silicon.