應用DSMC於垂直式旋轉噴嘴CVD反應腔體內熱流場分析

Abstract

本篇論文是利用DSMC法來模擬垂直式Cu-LPCVD反應腔體內的熱流場分析，並且配合國科會產學合作計畫[銅化學氣相沉積系統之研製，計畫編號：NSC87-2622-E-009-004]，將模擬結果提供給廠商作為設計組裝反應腔體的參考。應廠商組裝設計考量上要求，在本論文中我們探討旋轉噴嘴而固定基座條件的模擬研究。探討的條件包括不同的沉積壓力、加熱溫度、進口流量、噴嘴轉速、進口載氣（Carrier Gas）等物理條件；以及改變不同的基座與噴嘴距離的幾何條件。同時分別以兩種不同的化學反應模式，探討基板上所進行的沉積反應。 模擬結果發現，在不同的噴嘴轉速下沉積均勻度並無太大的差別，而沉積均勻最佳的噴嘴轉速在10∼20rpm範圍內。增加進口壓力雖可增加沉積率，但會降低薄膜的沉積均勻度。增加進口反應物的比例對於沉積率的提昇，比增加進口壓力來的顯著，而且所得的沉積均勻度也較佳。在基板與噴嘴距離方面，距離越短時沉積均勻度較佳且沉積率也較好，但是設計上必須考慮到機械手臂進出反應腔體輸送晶片所需的空間。不同進口載氣方面，當載氣的分子量越小時所得到的沉積率較快，但是沉積均勻度較差。基座加熱溫度不宜太高，以免造成噴嘴溫度過高使反應物的沈積於噴嘴處而造成阻塞。。

This thesis applies a numerical technique, DSMC, to simulate the thermal flow field in a vertical low-pressure Cu-CVD reactor. It is incorporated with a project supported by a manufacturer and the National Science council, ROC, under a contract, NSC87-2622-E-009-004. The main purpose is to provide the simulation data as a reference for designing the reacting chamber. According to the requirement of the manufacturer, the effects of rotating injector with fixed suscepter are investigated numerically in this thesis. The parametric studies are based on the changes in physical conditions, such as reactor pressure, temperature of substrate, inlet flow rate, angular velocity of rotating injector and carrier gas. The effect of distance between the injector and substrate is also studied. In the meantime, the influence of two different chemical reaction models on the surface deposition of substrate is considered as well. The results show that a good deposition uniformity for the angular velocities within the domain of 10 to 20 rpm can be achieved. When the reactor pressure increases, the deposition rate increases but the uniformity becomes worse. Increasing the percentage of reactant in precursor can raise the deposition rate more effectively than increasing the reactor pressure. It can also obtain a better deposition uniformity. A higher deposition rate and a better deposition uniformity can be reached by shorting the distance between the injector and substrate. However, an enough distance should be reserved to let the robot arm be able to deliver the wafer into and out from the reacting chamber. When a carrier gas with lower molecular weight is used, a higher deposition rate but with a worse deposition uniformity is found. The high temperature of substrate results in a high temperature in the injector, therefore, the temperature of suscepter suggested not too high in order not to make the reactant deposition on the its aperture to block the transportation of carrier gas and reactants.