LPCVD製程中之熱輻射分析

Analysis of Radiation in LPCVD Furnace

謝宜樺(Yi-Hwa Hsieh)

指導教授 ： 林育才

元智大學/工程學院/機械工程學系/碩士(1997年)

摘要

低壓的高速熱處理LPCVD為IC晶片製造的重要製程之一，其在加熱過
程中晶圓上的溫度分佈不均勻，所造成的化學反應不均勻（如沈積、氧化
等）及過強的熱應力，嚴重影響晶圓的品質，而此類問題至今仍無法得到
妥善的解決。因此，本文主要是針對LPCVD反應爐，進行分析各種不同種
類的燈源在此幾何模型內所產生之熱輻射效應對晶圓的影響，並對其燈源
的配置做簡單的探討，分析在加熱過中晶圓溫度的變化情形。藉以提供給
工業界參考，以改善LPCVD反應爐的設計，提升其晶圓製程的品質。

結果顯示，LPCVD反應爐內各種不同種類之燈源配置所產生的熱輻射
效應包括反射、吸收及放射等行為，皆對晶圓表面熱通量的分佈情形有相
當大的影響，進而影響晶圓表面溫度的均勻性。就燈源的種類而言，其燈
罩式燈源較不容易達成晶圓上均勻的熱通量分佈，其他種類之燈源就較有
可能使晶圓上有均勻的熱通量分佈。在LPCVD反應爐內加入圓盤式反射盤
後不只能降低晶圓的邊際效應，且對因光罩或不同的表面沈積而使晶圓表
面的熱輻射係數改變所形成的溫度不均現象也能有所改善，但其加熱速度
減緩是必須改進之處；而在LPCVD反應爐內加入圓板式加熱板時，則必須
在圓板上方給予特殊的熱輻射通量分佈，才能降低晶圓的邊際效應。

關鍵字

化學氣相沈積 ； 熱輻射 ； 熱輻射追蹤法 ； 溫度均勻性 ； 晶圓製程

並列摘要

Low pressure chemical vapor deposition (LPCVD) process is
one of the most important manufacturing processes to make IC
circuits. The resulting nonuniform temperature across the wafer
during the process is still a problem, especially for large
size of wafer. The nonuniformity of temperature would result in
nonuniform deposition layer on the wafer. Furthermore, it would
cause strong thermal stress on the wafer and reduce the yield
of the product. The purpose of the study is to analyze the
radiative phenomena during the LPCVD process and investigate
the effects of the parameters, such as the types of lamps,
geometrical arrangement of lamps and the wafer, etc., on the
wafer temperature uniformity.
The results show that the distribution of the arriving heat
flux on the wafer is significantly affected by the types of the
lamps and the flux distribution has direct effect on the wafer
temperature. It is not easy to have a uniform heat flux on the
wafer for the lamps with a reflecting cover over it. For other
types of lamps the geometrical parameters can be optimized in
order to obtain a better heat flux distribution. The results
also show that the inclusion of a reflecting plate not only can
reduce the wafer edge effect but also can improve the
temperature uniformity across the wafer having different
optical properties. However, the ramp-up rate becomes lower and
has to be further studied. For the case of having an indirect
heating plate over the wafer, it is shown that the uniform
temperature distribution can be obtained only when the flux
on the heating plate must be adjusted carefully.

並列關鍵字

CVD ； Radiation ； ray-tracing ； temperature uniformity ； wafer manufacture

參考文獻

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