Substrate joining method and 3-D semiconductor device

• US 8,257,528 B2
• Filed: 08/13/2009
• Issued: 09/04/2012
• Est. Priority Date: 08/15/2008
• Status: Active Grant

• Current Assignee: Shin-Etsu Chemical Company Limited
• Original Assignee: Shin-Etsu Chemical Company Limited
• Inventors: Yagihashi, Fujio, Hamada, Yoshitaka, Asano, Takeshi
• Primary Examiner(s): Crispino, Richard
• Assistant Examiner(s): Schwartz, Philip N
• Application Number:
  US12/540,764
• Publication Number:
  US 20100040893A1
• Time in Patent Office: 1,118 Days
• Field of Search: 156/306.9
• US Class Current: 156/87
• CPC Class Codes: H01L 21/2007 Bonding of semiconductor wafers to insulating substrates or to semiconducting substrates using an intermediate insulating layer H01L21/2011 takes precedence; bonding of semiconductor wafers to semiconductor wafers for junction formation H01L21/187
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor

Abstract

A pair of substrates each having a bonding surface are joined together by interposing a bond layer precursor coating between the bonding surfaces of the substrates and heating the precursor coating to form a bond layer. Prior to the joining step, the substrate on the bonding surface is provided with a gas-permeable layer. Even when a material which will evolve a noticeable volume of gas upon heat curing is used as the precursor coating, substrates can be joined via a robust bond without the peeling problem by gas evolution.

Claims

1. A method for joining integrated circuit substrates together, comprising the steps of joining a pair of integrated circuit substrates each having a bonding surface with a bond layer precursor coating interposed between the integrated circuit substrate bonding surfaces, and heating the precursor coating to form a bond layer,

the method further comprising the step of providing one or both of the integrated circuit substrates bonding surfaces directly with a porous gas-permeable layer prior to the joining step,

said bond layer precursor coating being formed by using a material which evolves gas through reaction when heat cured into the bond layer.

2. The method of claim 1 wherein said porous gas-permeable layer is formed by applying a coating composition comprising a silicon base material and heating the coating so as to be gas permeable.

3. The method of claim 2 wherein the silicon base material is a silicon oxide base material.

4. The method of claim 3 wherein the silicon oxide base material comprises an organic silicon oxide compound.

5. The method of claim 1 wherein said porous gas-permeable layer is a porous film formed by CVD method and having a dielectric constant k of up to 3.

7. The method of claim 1 wherein said bond layer precursor coating is a coating comprising an inorganic or organic silicon oxide base polymer.

8. The method of claim 2 wherein said silicon base material is a silicon oxide base polymer of which the starting reactant is a hydrolyzable silane compound comprising a tetrafunctional alkoxysilane compound of the general formula (1):

Si(OR¹)₄  

 

(1)

wherein R¹ is a straight or branched C₁-C₄ alkyl group, four R¹ may be each independently the same or different, and a hydrolyzable silane compound of the general formula (2);

R²_mSi(OR³)_4-m 

 

(2)

wherein R² is a straight or branched C₁-C₄ alkyl group, and when a plurality of R2 are included, they may each independently the same or different;

R³ is an optionally substituted, straight or branched C₁-C₈ alkyl group, and when a plurality of R³ are included, they may be each independently the same or different; and

m is an integer of 1 to 3.

9. The method of claim 2 wherein said silicon base material is a silicon oxide base polymer of which the starting reactant comprises a silane compounds of the above formulae (1) and (2) wherein m=1, and a hydrolyzable silane compound capable of forming at least three crosslinks composed of oxygen atom and/or hydrocarbon, as represented by the following general formulae (3), (4) (5):

10. The method of claim 5 wherein said porous film is formed by using a material comprising a cyclic siloxane compound having hydrocarbon and alkoxy groups, as represented by the general formula (6):

6. A method for joining integrated circuit substrates together, comprising the steps of joining a pair of integrated circuit substrates each having a bonding surface with a bond layer precursor coating interposed between the integrated circuit substrate bonding surfaces, and heating the precursor coating to form a bond layer,

the method further comprising the step of providing one or both of the integrated circuit substrates bonding surfaces directly with a porous gas-permeable layer prior to the joining step, by applying a silicon oxide base film-forming composition comprising an inorganic or organic silicon oxide base polymer directly onto one or both of the substrate bonding surfaces and processing the composition into a silicon oxide base film serving as the porous gas-permeable layer,

said bond layer precursor coating being formed by using a material which evolves gas through reaction when heat cured into the bond layer.