Non-Contact Power Transfer via Metal Nanoparticle-Dispersed Ionic Liquid

A non-contact power transfer mechanism via an ionic liquid (IL) to a bipolar electrostatic wafer chuck (ESC) was developed. The liquid power transfer method can supply voltage to the ESC set on a floating bearing, with no metal contact points and friction contamination. It intended for use in vacuum processes for semiconductor fabrication. In this transfer mechanism, electrostatic charge-up occurs in the IL which is concerned with the degradation of the IL. Thus, a non-oxidized metal nanoparticle-dispersed IL was prepared to reduce the charge-up, and its effect on charge reduction was investigated. The nanoparticle-dispersed IL exhibited a significant reduction in charge-up compared to the pure IL during voltage supply to the ESC. Although decomposition products obtained from the sputtering process were detected from the sputtered IL in a vacuum environment, the partial pressure values of these products were set to 10-9 Pa, indicating that the damage to the IL from sputtering was limited. The non-oxidizing metal nanoparticle-dispersed IL effectively prevented IL degradation and was useful for the non-contact power supply mechanism. It exhibits the potential to contribute to advancements in semiconductor manufacturing equipment.