燈源加熱之垂直快速加熱爐內藉環形塊狀物和爐體倒裝去壓制混和對流流場

Abstract

本篇論文是利用實驗的流場觀測方法，在燈源加熱之快速加熱爐內在多孔板正下方放置一環形塊狀物去探究其浮力驅動渦旋流(buoyancy induced vortex flow)可能的壓制，而氣流回流是如何被這些塊狀物所影響將詳細的被研究。實驗的四個不同塊狀物其氣體流量變化是從4到20 slpm並且晶圓和進氣溫差是從5℃到20℃被測試。 從爐體內藉由不同塊狀物所拍攝的側視圖與沒有放置任何的塊狀物作比較，其結果指示放置大的塊狀物大體上能壓制並穩定浮力驅動渦旋流，並且有一些實驗情況其浮力驅動流能完全的被消除。此外，我們發現增加塊狀物的高度會導致沿著晶圓的徑向流體流動空間被縮小，進而使得壓制浮力驅動渦捲達到非常有效的效果；而增加塊狀物的徑向尺寸雖能加速爐體的軸向流體但壓制浮力驅動渦捲的效果較有限，但是卻能有效的壓制較小的內部渦捲。而一個在爐體內藉由放置不同的塊狀物的流場組織圖也能提供流場圖的輪廓描述。 除此之外，藉由爐體的倒裝能有效地壓制自然對流的影響，並且當氣體流量不高時，只有一個小的圓形渦捲出現在爐體的外部區域。

Experimental flow visualization is conducted in the present study to explore the possible suppression of the buoyancy induced vortex flow in a model, lamp heated vertical rapid thermal processor by installing an annular block right below the showerhead of the processor. How the gas flow recirculation affected by the presence of the block will be investigated in detail. In the experiment four different blocks are tested for the gas flow rate varied from 4 to 20 slpm and the wafer-to-inlet gas temperature difference from 5℃ to 20℃. The side view flow photos taken from the processing chamber installed with the different blocks are compared with those taken from the chamber without installing any block. The results indicate that the installation of a large block can substantially suppress and stabilize the buoyancy induced vortex flow. For some cases the buoyancy induced flow can be completely eliminated. Moreover, the increase in the block height is found to be very effective in suppressing buoyancy induced vortex roll due to the reduction of space for the radial flow moving along the wafer. The increase in the radial dimension of the block, which accelerates the axial flow in the chamber, is less effective in suppressing the buoyancy induced roll but is effective in suppressing the small inner roll. A flow regime map is provided to delineate the flow patterns in the chamber installed with the different blocks. Besides, the gas flow in the processing chamber with an upside down orientation can effectively suppress the natural convection effects and only a small circular roll appears in the outer zone of the chamber when the gas flow rate is not high.