Direct bonding and debonding of glass wafers for handling of ultra-thin glass sheets

Abstract

In this sturdy, we investigated the bonding and debonding of the glass wafers using Surface Activated Bonding (SAB) method with the Si and Fe intermediate layers. In the fabrication process of the Thin Film Transistors (TFTs) on the ultra thin glass substrates for the display devices, the glass substrates are handled at high temperature and can be easily deformed. In order to achieve the accurate handling of the ultra thin glass substrates, the glass substrates should be bonded to the carrier glasses, and shoul be debonded after the process. We modified the SAB process with the intermediate layers to control the bond strength of the glasses for the handling. The bonding of glasses by the SAB method endured the heating at 350-550°C and the bond strength as surface energy was controllable under under 1 J/m2. Additionally, the appearance of the voids in the interface were detected, and it indicated the similarity to the hydrophilic bonding. The result shows the feasibility of applying this technique as an alternative for the current TFT process.