Optimization of CMP process for TSV reveal in consideration of critical defect

The Behaviors of Alkaline Slurry during the CMP of TSV Backside Heterogeneous Microstructure

“…10 The height error and the overall height difference of Cu pillars caused by deep hole etching 3 cannot be eliminated (usually dozens or hundreds of nanometers), which brings some trobles to the micro-bump bonding and packaging. It is pionted out 11 that the high revealed Cu pillars brings hidden troubles (such as stress concentration and heterogeneous material removal) to the passivation and 2 nd CMP BVR process.…”

“…Hydrogen ion concentration (pH) is an important parameter, which can change the solution-wafer interfacial characteristics, as well as affect chemical reactions. [16][17][18] The pH value of TSV back side CMP slurry is usually within the range of [9][10][11][12] because basically Si CMP is conducted under alkaline condition 19 since hydroxyl ions have chemical effect on Si. H 2 O 2 is the best oxidizing agent in Cu CMP 20,21 and can also be used in Si presicion CMP process.…”