From Semiconductor Engineering:

Innovative materials are critical for maintaining integrity during advanced semiconductor manufacturing processes. Temporary bonding is being enabled by these new materials and is making a name for itself in the next generation of ultrathin wafer manufacturing.

Semiconductor wafers are being forced to become thinner as the push to shrink feature sizes and introduce full-scale 3D integration continues to grow.

While grinding wafers to less than 100 micrometers in thickness is a readily available process, moving to even thinner wafers (<50 µm) makes them exceedingly fragile. The stress of these extreme thinning processes and subsequent downstream metallization can cause additional stress on ultrathin wafers, contributing to warp or breakage.

The thin wafer handling process consists of temporarily mounting a device wafer to a carrier wafer with a polymeric bonding material system. This process is used to stabilize a wafer through harsh back-end processes while supporting the ultrathin device substrate. Two of the fastest growing release methods for debonding the wafer pairs are the laser and mechanical methods.

Source: Semiconductor Engineering: Temporary Bonding: Enabling the Next Generation of Ultrathin Wafers reposted by Silicon Valley Microelectronics, Inc.