Flow Field Visualization of a FOUP Under Different EFEM Arrangements During Open Door Condition

• Main Authors: LEE, TZU-CHIEH, 李子傑
• Other Authors: HU, SHIH-CHENG
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/f77m99

碩士 === 國立臺北科技大學 === 能源與冷凍空調工程系 === 107 === As the gate length of integrated circuits shrinks, the yield of semiconductor processes is challenged, and contamination-free manufacturing has become the most critical factor in semiconductor high-tech processes, especially integrated circuit manufacturing. The concept of contaminant control involves not only particle concentration control but also monitoring of Airborne Molecular Contamination (AMC). The control of particle concentration is usually captured by filters of different filtration efficiencies, which are also the main devices that make up the cleanroom. On the other hand, AMC may be removed by masking or purging method, the removal efficiency is related to the airflow pattern inside the Equipment Front-End Module (EFEM) and the Front Opening Unified Pod (FOUP). In most semiconductor process applications, the airflow is often deflected due to the different arrangement in the EFEM, which invades the FOUP and causes pollution. Taking the etching process as an example, in the process of waiting for the wafer to be etched and wet-washed in the mini-environment, the FOUP door will be released, so that the residual hydrogen fluoride and the moisture in the air are Oxygen produces a high concentration of fluorine, which in turn acts as a catalyst for the reaction of copper with oxygen, resulting in loss of double damascene pattern copper, which seriously affects the process yield of the wafer. Therefore, contamination control when the FOUP door is released during the process is critical. This study compares Conventional Purge and Diffuser Purge with Laminar Air Curtain's shielding method. The method of purging and providing Laminar Air Curtain is to supply Compress Dry Air from the rear and outside of the FOUP, creating a barrier from the inside out and drying, respectively, to block the invaded airflow into the FOUP. In this experiment, atomized ethylene glycol was used as the tracer gas, and the movement of the smoke was recorded by a high-speed camera to establish a flow field visualization technique. In order to prove and quantify the flow field visualization experiment, this experiment also recorded the relative humidity data of the FOUP. The experimental results show that the combination of the diffuser and the laminar air curtain exhibits excellent effects in blocking the external airflow in the different arrangement of the EFEM, and the both of those two devices can be practically applied in the semiconductor manufacturing process.