Modified Surface Activated Bonding Using Si Intermediate Layer for Bonding and Debonding of Glass Substrates

Abstract

This study reports the bonding and debonding technology based on the Surface Activated Bonding method for the handling of the thin glass substrates. The glass substrates are bonded by The Si intermediate layer oh under 10 nm thick. From the XPS analysis, the OH groups are formed in the bonding interface and the Si layer’s surface is oxidized by the reaction with the OH groups and water at high temperature. Additionally the Si intermediate layer remains on the deposited glass surface. AFM observation also shows the smooth debonded surfaces. From these results, the debonding at the bonding interface is confirmed.

Mechanism of bonding and debonding using surface activated bonding method with Si intermediate layer

“…To bond and debond glass substrates after the hightemperature process, we have proposed to apply the surface activated bonding (SAB) method in our previous study. [7][8][9] The SAB method is room temperature bonding, which enables interconnection between metal [10][11][12][13][14] and semiconductor [15][16][17] materials through atomic force. This bonding method has also bonded polymers, [18][19][20][21] and ionic materials, such as SiO 2 , 22,23) and compound semiconductors [24][25][26][27] at room temperature using thin Si intermediate and Fe nano adhesion layers.…”

“…We also combined the SAB method with hydrophilic treatment by exposing the bonding surfaces to N 2 to form OH groups on them. [7][8][9] The interfacial toughness 2γ was determined to be 1.9 J=m 2 before heating and 0.8 J=m 2 after heating. The proposed bonding process satisfied the requirement for TFT fabrication, that is, the bond strength should decrease after the high-temperature process to enable debonding.…”

Hydrophilic direct bonding and debonding of ultrathin glass substrates for high-temperature devices

“…Instead, direct bonding/detachment of glass substrate to and off carriers such as Si or thick glass substrates becomes a promising alternative. Techniques including surface activation bonding, [10][11][12] anodic bonding 13) and hydrophilic direct bonding 14) were commonly used for directly wafer bonding in Si and glass substrates. Yet direct bonding of glass substrates also faces difficulties for high-temperature processes.…”

“…The bonding strength between the ultrathin glass and carrier will become too high for an intact separation between them after high temperature processing. 10,11,15) It is the major focus of this work to present experimental results and the underlying theoretical background of a technique which lowers the bonding strength of direct hydrophilic glass bonding based on the reduction of initial surface hydroxyl groups.…”