• 반도체디스플레이기술학회지
• /
• 제22권2호
• /
• pp.17-23
• /
• 2023

In semiconductor manufacturing processes, a cleaning process is important that can remove sub-micron particles. Conventional wet cleaning methods using chemical have limits in removing nano-particles. Thus, physical forces of a mechanical vibration up to 1 MHz frequency, was tried to aid in detaching them from the substrates. In this article, we developed a 1 MHz quartz megasonic for a bare wafer cleaning using finite element analysis. At first, a 1 MHz megasonic prototype was manufactured. Using the results, a main product which can improve a particle removal performance, was analyzed and designed. The maximum impedance frequency was 992 kHz, which agreed well with the experimental value of 986 kHz (0.6% error). Acoustic pressure distributions were measured, and the result showed that maximum / average was 400.0~432.4%, and standard deviation / average was 46.4~47.3%. Finally, submicron particles were deposited and cleaned for the assessment of the system performance. As a result, the particle removal efficiency (PRE) was proved to be 92% with 11 W power. Reflecting these results, the developed product might be used in the semiconductor cleaning process.

• 반도체디스플레이기술학회지
• /
• 제22권4호
• /
• pp.66-71
• /
• 2023

This paper describes a hybrid cleaning method of silicon wafer combining nano-bubble and ultrasound to remove sub-micron particles and contaminants with minimal damage to the wafer surface. In the megasonic cleaning process of semiconductor manufacturing, the cavitation induced by ultrasound can oscillate and collapse violently often with re-entrant jet formation leading to surface damage. The smaller size of cavitation bubbles leads to more stable oscillations with more thermal and viscous damping, thus to less erosive surface cleaning. In this study, ultrasonic energy was applied to the wafer surface in the DI water to excite nano-bubbles at resonance to remove contaminant particles from the surface. A patented nano-bubble generator was developed for the generation of nano-bubbles with concentration of 1×10⁹ bubbles/ml and nominal nano-bubble diameter of 150 nm. Ultrasonic nano-bubble technology improved a contaminant removal efficiency more than 97% for artificial nano-sized particles of alumina and Latex with significant reduction in cleaning time without damage to the wafer surface.

• 반도체디스플레이기술학회지
• /
• 제13권1호
• /
• pp.1-6
• /
• 2014

In this study, to analyze characteristics of acoustic pressure for spot spray type megasonic, FEM analysis was performed for variable parameters based on the structure of commercial one. and 2 models of transmitter were designed and fabricated, and then acoustic pressure distribution(APD) of the transmitter was measured and compared to the commercial. The results of this experiment show that maximum acoustic pressure of model 1 was higher to 1.6 times compared to the commercial, and model 2 was higher to 1.23 times. Through the course of this study, design technology of transmitter has been developed by means of FEM analysis and experiment for characteristics of acoustic pressure. Also, it is expected to be useful in the development of high power spray type megasonic that is necessary with advance in semiconductor technology.