Promoting of charged-device model/electrostatic discharge immunity in the dicing saw process

摘要

Polyimide (PI) dielectric as a heatproof material is commonly employed in the integrated circuit (IC) industry. In the dicing saw assembly process, de-ionized (D.I.) water which has a higher resistance is rubbed on PI material. Hence, negative electrostatic charges are generated and accumulated on gate oxide capacitor or p-n junction capacitor in each IC chip. Since the discharge path is isolated during this time, sufficient cumulated charges through some feasible electrical path will damage the IC devices in this process step. Such damaged ICs exhibit function failure. A CO_2 gas flow under 2-3 kgw/cm~2 gas pressure to form a weak carbonic acid in water is efficient to conduct out the accumulated charges and adequately prevent the charge damage on IC devices. The final-test yield in sub-micron analog power complementary metal-oxide-semiconductor (CMOS) ICs was impressively increased from 80% to 98%.