WAFER DEBONDING USING LONG-WAVELENGTH INFRARED RADIATION ABLATION
Structures and methods are provided for temporarily bonding handler wafers to device wafers using bonding structures that include one or more releasable layers that absorb long-wavelength infrared radiation to achieve wafer debonding by infrared radiation ablation.
1 .˜ 11 . (canceled)
12 . A stack structure, comprising:
a device wafer;
a silicon handler wafer; and
a bonding structure disposed between the device wafer and the silicon handler wafer, wherein the bonding structure bonds the device and silicon handler wafers together, wherein the bonding structure comprises:
an adhesive layer; and
a metallic layer that is vaporizable by infrared ablation to serve as a releasable layer of the bonding structure by infrared exposure of the bonding structure through the silicon handler wafer, wherein the metallic layer has a thickness in a range of about 5 nanometers to less than 100 nanometers which is configured to be substantially or completely vaporized by infrared ablation to cause the release of the device wafer from the silicon handler wafer as a direct result of the infrared ablation of the metallic layer.
13 . The stack structure of claim 12 , wherein the adhesive layer further serves as a releasable layer by infrared ablation of at least a portion of the adhesive layer at an interface between the adhesive layer and the metallic layer due, in part to, absorption of infrared energy by the metallic layer.
14 . The stack structure of claim 12 , wherein the metallic layer is ablated by irradiation of infrared energy having a wavelength in a range of about 5 μm to about 30 μm.
15 . (canceled)
16 . The stack structure of claim 12 , wherein the thin metallic layer is formed of at least one of Al, Sn, and Zn.
17 . The stack structure of claim 12 , wherein the metallic layer is directly deposited on a surface of the silicon handler wafer.
18 . The stack structure of claim 12 , wherein the metallic layer is formed with a rough surface to increase a contact area between the metallic layer and the adhesive layer.
19 . The stack structure of claim 12 , wherein the adhesive layer comprise a first adhesive layer and a second adhesive layer, wherein the metallic layer is disposed between the first and second adhesive layers.
20 . The stack structure of claim 12 , further comprising a protective metallic layer disposed between the releasable layer and the device wafer to protect the device wafer from being irradiated with the infrared energy.
21 . The stack structure of claim 20 , wherein the protective metallic layer is formed of at least one of titanium, gold or copper.
22 . The stack structure of claim 12 , wherein the adhesive layer comprises a polymer material having infrared energy absorbing nanoparticles.
23 . The stack structure of claim 22 , wherein the nanoparticles are formed of at least one of Sn, Zn, Al, carbon nanotubes and graphene.
24 . The stack structure of claim 12 , wherein the device wafer is a silicon wafer.
25 . A stack structure, comprising:
a device wafer;
a silicon handler wafer; and
a bonding structure disposed between the device wafer and the silicon handler wafer, wherein the bonding structure bonds the device and silicon handler wafers together, wherein the bonding structure comprises an adhesive layer, wherein the adhesive layer comprises a layer of adhesive material comprising infrared energy absorbing nanoparticles that are vaporizable by infrared ablation so that the adhesive layer serves as a releasable layer by vaporization of the nanoparticles when infrared radiation is directed at the bonding structure through the silicon handler wafer, wherein the adhesive layer comprises a concentration of infrared energy absorbing nanoparticles which is configured to be substantially or completely vaporized by infrared ablation to cause release of the device wafer and the silicon handler wafer as a direct result of the infrared ablation of the infrared energy absorbing nanoparticles.
26 . The stack structure of claim 25 , wherein the nanoparticles are formed of at least one of Sn, Zn, Al, carbon nanotubes and graphene.
27 . (canceled)
28 . (canceled)
29 . The stack structure of claim 25 , further comprising a non-ablating protective metallic layer disposed between the bonding structure and the device wafer to protect the device wafer from being irradiated with the infrared energy and to reflect the infrared energy away from the device wafer.