Ephemeral bonding
View Patent ↗Compositions containing an adhesive material, a release additive and a compatibilizer are suitable for temporarily bonding two surfaces, such as a wafer active side and a substrate. These compositions are useful in the manufacture of electronic devices where a temporary bonding of a component to a substrate is desired.
1. A method of releasably attaching a semiconductor wafer to a carrier substrate comprising:
(a) providing a semiconductor wafer having a front side and a back side;
(b) providing a carrier substrate having an attachment surface;
(c) disposing a temporary bonding composition comprising a curable adhesive material, a release additive and a compatibilizer between the front side of the semiconductor wafer and the attachment surface of the carrier substrate; and
(d) curing the adhesive material to provide a temporary bonding layer disposed between the front side of the semiconductor wafer and the attachment surface of the carrier substrate;
wherein the temporary bonding layer adjacent to the attachment surface of the carrier substrate comprises a relatively lower amount of the release additive and the temporary bonding layer adjacent to the front side of the semiconductor wafer comprises a relatively higher amount of the release additive;
wherein the release additive is a polyether compound; and wherein the release additive is free of silicon.
2. The method of claim 1 wherein the curable adhesive material is chosen from polyarylene oligomers, cyclic-olefin oligomers, arylcyclobutene oligomers, vinyl aromatic oligomers, and mixtures thereof.
3. The method of claim 1 wherein the release additive is chosen from polyalkylene oxide homopolymers or polyalkylene oxide copolymers.
4. The method of claim 1 wherein the compatibilizer is a polyether comprising butylene oxide units.
5. The method of claim 4 wherein the compatibilizer is a polybutyleneoxide having a formula R 14 —O—(C 4 H 8 O) z —(C 3 H 6 O) y —R 15 ; wherein each of R 14 and R 15 is independently chosen from H, (C 1 -C 20 )alkyl, H—(R 16 O) w —R 17 or (C 6 -C 20 )aryl; each R 16 and R 17 are independently (C 1 -C 6 )alkylidene; w is an integer from 1 to 5; z is an integer from 5 to 250, and y is an integer from 0 to 200.
6. The method of claim 1 further comprising the step of treating the attachment surface of the carrier substrate with an adhesion promoter prior to contact with the temporary bonding composition.
7. The method of claim 1 further comprising the steps of: (e) performing an operation on the back side of the semiconductor wafer; and (f) separating the front side of the semiconductor wafer from the temporary bonding layer.
8. The method of claim 1 wherein the release additive contains one or more polar end groups chosen from alkoxy, aryloxy, hydroxy, carboxylate, alkoxycarbonyl, mercapto, alkylthio, primary amine, secondary amine, and tertiary amine.
9. The method of claim 1 wherein the release additive and the combatilizer are in a weight ratio of 5:1 to 1:5.
10. The method of claim 1 wherein the release additive phase separates from the adhesive material during curing of the adhesive material.
11. The method of claim 1 wherein the compatibilizer lowers an elastic modulus of the cured adhesive material, as compared to when no compatibilizer is used.
12. The method of claim 1 wherein the compatibilizer does not phase separate from the adhesive material during curing of the adhesive material.
13. The method of claim 1 wherein the compatibilizer increases the amount of the release additive that can be dissolved or dispersed in the adhesive material as compared to when no compatibilizer is used.
14. The method of claim 1 wherein the compatibilizer does not function as a release additive.