Study of Ultra Thin Oxide Uniformity in Rapid Thermal Processing

• Main Author: 陳健隆
• Other Authors: 胡振國
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/59666661345214255491

碩士 === 國立臺灣大學 === 電機工程學研究所 === 87 === The most important feature of rapid thermal processing (RTP) lies in its use of high energy radiation source to achieve the heating of a wafer in a rather short time (compared with the heating by a furnace). This feature plays a very important role in the manufacturing technology for the shrinkage of the dimension in ULSI devices. However, the thermal non-uniformity problem of RTP remains unsolved. This thesis is to study the thickness non-uniformity problem of the oxide by RTP. In Chapter 1, the kinetics of thermal oxidation growth and the RTP system is introduced. Next, to explore how to grow uniform ultra thin oxide, the understanding of the mechanisms of the oxide growth at the initial stage from the proposed models is necessary. Therefore, in Chapter 2, the proposed models to explain the anomalous fast initial growth rate of thermal oxidation are reviewed. Though none of the models has been convincingly accepted as more valid than the others, the study of these models provides diverse angles to observe the following experimental results. Combined with the concepts of the models and the analysis of the experimental results, a mechanism to explain the experimental results of ultra thin oxide growth is proposed. In addition, from the analysis of the experimental results of the oxide thickness uniformity, a method is proposed to improve the uniformity of ultra thin oxide. Next, to further understanding the RTP system to improve the thermal uniformity, a simulation of RTP system for temperature distribution in both the heating process and the cooling process is desired. Hence, in Chapter 3, the basic concept of heat transfer is introduced and then the construction process and the results of the simulating of the heating of the wafer in RTP. Besides, the simulation is applied to observe the temperature distribution of the wafer with patterned susceptors under it. The effectiveness of using silicon patterned susceptors for temperature compensation was previously shown by experiments. Now, it is further demonstrated by the simulation and different styles of pattern susceptors could be evaluated by simulation before the realization by experiments. Therefore, the setup of the simulation not only makes possible the observation of thermal dynamic behavior in RTP but also facilitated the better design of patterned susceptors to improve the uniformity. Finally, the conclusion of the works above is forwarded in Chapter 4.