Laser ablation of polyetheretherketone films for reversible wafer bonding

Abstract

A reversible wafer bonding method has been developed that enables high-temperature processing of thinned silicon wafers. The silicon wafers are bonded to Pyrex carriers using a polyetheretherketone (PEEK) film, which melts at 343 °C, and provides a very strong bond. Debonding is accomplished by UV laser ablation through the Pyrex carrier and can be facilitated by coating the Pyrex wafer with Teflon. Most of the PEEK film remains on the silicon wafer after debonding and is removed with solvents. Precoating the silicon with germanium/tetraethyl orthosilicate (TEOS) might enable PEEK removal without solvents. This germanium/TEOS layer lifts off with the PEEK film during laser ablation.

Temporary Bonding and Debonding in Advanced Packaging: Recent Progress and Applications

“…and polymers (polyimide, polyether ether ketone (PEEK), polydimethylsiloxane (PDMS), etc.) were also later adopted as temporary bonding materials [22][23][24][25][26]. Moreover, the main difference between these temporary bonding materials is that a corresponding debonding method needs to be developed to meet the non-destructive debonding of ultrathin wafers.…”