Ephemeral bonding
Compositions containing an adhesive material and a release additive 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 component, such as an active wafer, is temporarily bonded to a substrate, followed by further processing of the active wafer.
1. A structure comprising: a semiconductor wafer having a front side and a back side; a carrier substrate having an attachment surface; and 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 comprises a cured adhesive material and a polyether release additive, the release additive being free of silicon; wherein the temporary bonding layer is composed of a first region adjacent to the attachment surface of the carrier substrate having a relatively lower amount of release additive and a second region adjacent to the front side of the semiconductor wafer having a relatively greater amount of release additive.
2. The structure of claim 1 further comprising an adhesion promoting layer disposed between the temporary bonding layer and the attachment surface of the carrier substrate.
3. The structure of claim 1 wherein the temporary bonding layer and the front side of the semiconductor wafer have an adhesion energy of <3 J/m 2 .
4. The structure of claim 1 wherein the temporary bonding layer and the attachment surface of the carrier substrate have an adhesion energy of >30 J/m 2 .
5. The structure of claim 1 wherein the cured adhesive material is chosen from polyarylene polymers, cyclic-olefin polymers, arylcyclobutene polymers, vinyl aromatic oligomers, and mixtures thereof.
6. The structure of claim 1 wherein the cured adhesive material is an arylcyclobutene polymer.
7. The structure of claim 6 wherein the cured adhesive material has a modulus of >1 GPa, and an elongation of <20% at a breaking point.
8. The structure of claim 1 wherein the release additive is chosen from the group consisting of polyalkylene oxide homopolymers and polyalkylene oxide copolymers.
9. The structure of claim 1 wherein the release additive comprises terminal groups chosen from the group consisting of hydroxy, alkoxy, aryloxy, and mixtures thereof.
10. The Structure of claim 1 wherein the release additive compound is chosen from polyethylene glycol, polypropyleneglycol, poly(1,3-propanediol), polybutyleneglycol, poly(tetrahydrofuran), ethylene glycol-propylene glycol copolymers, and mixtures thereof.