Temporary Wafer Bonding and Debonding for 3D Integration Using an Electrochemically Active Polymer Adhesive

Abstract

The use of thin silicon wafers is an enabling technology for 3D integration in the semiconductor industry. However, thin silicon wafers are fragile to handle and reliable solutions are required for thin wafer handling. This paper reports a novel method of bonding and debonding a thin wafer (<50 μm) using an electrochemically active polymer adhesive. In the presented method the carrier wafer is first spin coated with the adhesive and then bonded to the device wafer by applying force and temperature. Debonding of the wafer is realized at room temperature by applying a voltage between the carrier and the device wafer, which substantially reduces the bond strength. The bonding and debonding properties of the adhesive show that temporary wafer bonding using electrochemically active adhesives has the potential to be an attractive approach for temporary wafer bonding for thin wafer handling in 3D integration processes.

The effect of surface morphology on the peel performance of UV-induced adhesion-reducing adhesives

“…The tape has a high adhesive strength, which allows it to hold silicon wafers during processing [6]. After processing, the tape loses its adhesive properties and the wafers can be easily picked up [7,8]. Some adhesionreducing adhesives have been reported in recent years, and they can be divided into three types: degradationinduced debonding, and light/heat and UV induced crosslinking debonding [9][10][11][12].…”

Temporary Wafer Bonding by Polyelectrolyte Interlayers

“…Using polymers such as epoxies, thermoplastics, and photo resists, the temperature dependence of adhesive forces of the polymers can be utilized [1]. Alternatively electrochemically active polymer adhesives can be used that can be debonded by applying an electrical voltage [2]. This paper presents the use of interfacial polyelectrolyte multilayers for temporary wafer bonding of silicon wafers.…”