Analysis of Heat Transfer and Thermal Stress of Wafers in Rapid Thermal Processing Furnaces

• Main Authors: Liu, Yi-Rong, 劉宜榮
• Other Authors: Chu, Hsin-Sen
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/82924718743983149496

碩士 === 國立交通大學 === 機械工程研究所 === 86 === 　　This surdy investigates heat transfer and thermal stress of wafer in a rapid thermal processing -type oven used for semiconductor processes. Thermal st11resses that are induced by temperature nonuniformity due to a heat loss at the edge of the wafer are calculated and compared to yield stress of silicon at the appropriate temperature and strain rate. 　　The model in this study includes radiant heat transfer to the wafer from the lamps, heat conduction within the wafer, adn emission of radiation from the wafer. The finite-difference scheme was employed to solve the two-dimensional heat conduction equation, from which the radial temperature profile could be simulated . The uniform and Gaussian distribution heat flux were also used to demonstrate the edge effect and discuss the relation between the temperature profile and stress field . In this study, the uniform-temperature model was proposed to improve the temperature uniformity and reduce thermal stresses of the wafers in the transient behavior. Finally, the temperature vand thermal stress of wafers in different sizes are also studied. 　　The results show that there is a heat loss at the edge of the wafer which produces a dcrease in temperature toward the edge. Comparison between Gaussian distribution and uniform heat flux show that the effect of the radiant heat flux distribution over the wafer in temperature uniformity is important. Edge effect of wafer thickness is more pronounced than that of wafer radius.