The fundamental characteristics of a thermomechanical resist removal-cleaning system using cryogenic micro-nano solid nitrogen spray flow was investigated using a new type of integrated measurement coupled numerical technique. The effect of ultra-high heat flux cooling on the resist removal performance due to the thermal contraction of resist material was clarified. It was numerically predicted that resist removal performance could be improved by the scraping effect of impinging micro-solid nitrogen particle with plastic deformation in the narrow region between the resist. Furthermore, it was numerically and experimentally found that the hybrid interactive effects of fluid mechanical force by impingement of micro-solid particles and the thermomechanical effect due to ultra-high heat transfer characteristics contribute to the resist removal-cleaning process.

The innovative characteristics of the cryogenic single-component micro-nano solid nitrogen (SN 2 ) particle production using super adiabatic Laval nozzle and its application to the physical resist removal-cleaning process are investigated by a new type of integrated measurement coupled computational technique. The originality to be noted in the present study is that the continuous production of micro-nano SN 2 particle is achieved by using single component gas-liquid two-phase flow of subcooled nitrogen through a Laval nozzle (converging-diverging nozzle). As a result of present computation, it is found that high-speed ultra-fine SN 2 particle is continuously generated due to the freezing of liquid nitrogen (LN 2 ) droplet induced by rapid adiabatic expansion of subsonic subcooled two-phase subcooled nitrogen flow passing through the Laval nozzle. Furthermore, the effect of SN 2 particle diameter, injection velocity, and attack angle to the wafer substrate on resist removal-cleaning performance is investigated in detail by integrated measurement coupled computational technique.

Abstract. The ultra-high heat flux cooling characteristics and impingement behavior of cryogenic micro-solid nitrogen (SN 2 ) particles in relation to a heated wafer substrate were investigated for application to next generation semiconductor wafer cleaning technology. The fundamental characteristics of cooling heat transfer and photoresist removal-cleaning performance using micro-solid nitrogen particulate spray impinging on a heated substrate were numerically investigated and experimentally measured by a new type of integrated computational-experimental technique. This study contributes not only advanced cryogenic cooling technology for high thermal emission devices, but also to the field of nano device engineering including the semiconductor wafer cleaning technology.