The Macroscopic And Microscopic Experimental Study Of Interface Adhesion Of PDMS-CDs

At present,with the advent of 5G era,the demand for chip performance and volume in many industries,such as communications and computers,is increasingly high,which makes the device wafer thickness smaller and smaller.As a result,the smaller wafer thickness leads to the increasingly prominent problem of device wafer rupture during wafer transfer.Thermal slip debonding,mechanical stripping debonding and laser stripping debonding are widely used in the wafer transfer process of current chip manufacturing process with their simple technological steps and reliable bonding properties.But the three mainstream methods,in the process of bonding adhesive removal,would result in higher wafer interface temperature.The general working temperature is in the range of 200 ? to 300 ?.Due to the thermal expansion coefficient mismatch of wafer bonding materials and devices,the thermal stress could result in the rupture of ultra-thin device wafer,buckling damage,etc.Therefore,the research on the bonding materials,the simplicity and reliability of the wafer transfer process,and the debonding method with less damage to the device wafer has a great significance.In this thesis,the bonding and debonding behaviors in the temporary bonding are studied experimentally.The research contents are as follows:(1)Based on the dry adhesion mechanism,the adhesion array with high aspect ratio was fabricated as the bonding material.The adhesion modification of polydimethylsiloxane(PDMS)by doping carbon quantum dots(Carbon dots)to produce bonding material samples with different CDs doping concentration.At the same time,the atomic force microscope(AFM)and the independently designed macro-adhesion test system were used to test the micro-adhesion and macro-adhesion strength of the bonding material between the silicon specimen surface under different working conditions.(2)The effective debonding control mode of PDMS-CDs bonding materials was established by testing under different working conditions,and the reliability test of bonding strength was conducted by means of macroscopic adhesion strength test bench.The surface adhesion of bonding materials with different CDs dopingconcentrations and Silicon(Si)samples under different working conditions was studied by Fourier infrared spectroscopy and contact angle experiment,and the surface adhesion work and surface hydrogen bond concentration of PDMS-CDs bonding materials with different concentrations under different working conditions were obtained,thus revealing the working mechanism of PDMS-CDs bonding materials.