Authors: S.H. Parng, H.J. Yang and T.K. Shia
Affilation: Microsystem Technology Common Laboratory, Taiwan
Pages: 353 - 356
Keywords: fusion bonding, microchannel, electrode, glass, surface roughness
Objectives: Bonding surface preparation, process conditions, and integrated on-chip metal sheet resistance variation during bonding process were investigated in this work. <br>Methods: We flatten the surface of the etched micro-channels with a fresh solution of HF:H2O (1:1.5) at 20℃ for 10 seconds before fusion bonding. The electrodes layer of Titanium/Platinum (500A/2000A) on glass substrate would be cleaned with isopropyl alcohol (IPA) solution for 3 minutes. All of the clean steps followed by a rinse in DI water. The drilled channel chip was thermally bonded to the RTD/heater chip used a programmable vacuum furnace<br>Results: Spectrophotometer images and surface roughness were compared for quantification of the surface microtopography with and without etching chemical treatment. The smoother surface can be achieved on glass wafers treated with diluted HF solution than those untreated. The excellent glass fusion bonding result can be achieved no matter Ti/Pt films are fabricated on the glass surface or not. From these SEM photos, it can be seen that the interface of the two glass plates is not observable. The average resistance drops by about 26% after bonding, whereas the bonding process improves the stability of the resistance by around 31% standard deviation individually.