Speaker
Jun Ishimoto
(Tohoku University)
Description
The fundamental characteristics of the cryogenic single-component micro-nano solid nitrogen (SN2) particle production using super adiabatic Laval nozzle and its application to the physical photo resist removal-cleaning technology are investigated by a new type of integrated measurement coupled computational technique. To elucidate the detailed mechanism of micro-nano SN2 particle generation, an integrated CFD (Computational Fluid Dynamics) analysis was carried out to clarify the cryogenic particle heat transfer mechanism that is difficult to obtain by conventional measurement. For the formulation of governing equations, the single micro-nano SN2 particle’s thermohydrodynamic behavior with phase change is governed by Navier-Stokes equations, continuity equations and energy equations. The defining feature of this phenomenon is the intense evaporation (and later condensation, solidification) that takes place at the interface of the SN2 particle and surrounding gas-phase.
The originality to be noted in the present study is that the continuous production of micro-nano SN2 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 the present computation, it is found that high-speed ultra-fine SN2 particles are continuously generated due to the freezing of liquid nitrogen (LN2) droplet induced by rapid adiabatic expansion of subsonic subcooled two-phase nitrogen flow passing through the Laval nozzle. Furthermore, the effect of the SN2 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.
This study is not only characterized by the advanced cryogenic cooling technology for high thermal emission device, but also contributes to different academic fields closely related to the semiconductor wafer cleaning technology.
Author
Jun Ishimoto
(Tohoku University)
Co-authors
Mr
Haruto Abe
(Graduate School of Information Science, Tohoku University)
Dr
Naoya Ochiai
(Institute of Fluid Science, Tohoku University)
