| 摘要: | 半導體電子元件製程中，在清洗過程常會遇到的pattern collapse的問題，利用Surface Evolver模擬得知藉由降低表面張力去減少此問題發生的機率，再利用實驗將常作為清洗液的過氧化氫，添加不同界面活性劑 (TTAB、Triton X-100)，可以得到其 CMC 值與以水當溶劑時相同，而其中 Triton X-100 更能有效的降低表面張力，且添加的界面活性劑量更少可以減少與pattern作用產生的副作用。
過氧化氫的分解反應易受 pH 值、溫度、雜質（金屬離子）所影響，本研究利用自製簡易的穩定性量測系統，從溫度、pH 值的角度去了解在不同情況下的穩定性，再利用模擬計算其反應速率的變化。過氧化氫在添加硫酸銅水溶液會使分解反應加速，因分解反應放熱，其溫度會增加，而溫度提升又更加速了分解反應的進行，經過一段時間溫度急遽上升，此時的 pH 值也因為酸性的過氧化氫分解成水，跟著急遽上升。在添加螯合劑 EDTA 或 CDTA 後，因螯合劑能與金屬離子結合，能抑制過氧化氫的分解，提高其穩定性，其中 CDTA 穩定的效果比 EDTA 好，而螯合劑的量越多，其穩定效果越好。過氧化氫在添加TMAH溶液後，因 pH 值的上升，使分解反應加速。
;In the process of micro or nano electro mechanical system manufacturing, pattern collapse is widely observed during the cleaning process. By Surface Evolver simulation, the underlying mechanism of pattern collapse is explored. To avoid pattern collapse, the surface tension of the rinse liquid must be reduced. In experiment, different surfactants such as TTAB and Triton X-100 is added to the solution of hydrogen peroxide to reduce its surface tension. For TTAB and Triton X-100, the value of critical micelle concentration (CMC) for the solution of hydrogen peroxide is the same as that for water. Moreover, Triton X-100 is better than TTAB for the solution of hydrogen peroxide due to the achievement of the lower surface tension. Additionally, less Triton X-100 is needed to reach CMC and the side effect come from the interaction between surfactant and pattern can be reduced.
The decomposition of hydrogen peroxide (H2O2) can be affected by the acidity or basicity, temperature, impurity of an aqueous solution. In this study, the simple measuring system is employed to measure the temperature and pH value of an aqueous solution of H2O2. With the help of the heat balance equation, the decomposition rate associated with the stability of H2O2 under different temperature and time can be estimated. As the aqueous solution of copper (II) sulfate (CuSO4) is added, the decomposition of H2O2 is promoted due to the catalysis of copper (II) ion and large amount of heat is released, leading to the increase of the temperature of solution. Simultaneously, the decomposition of H2O2 can also be accelerated by increasing temperature. After a while, both temperature and pH value of the solution will increase significantly due to the rapid decomposition of acidic H2O2. By adding chelating agents such as EDTA and CDTA, the decomposition of H2O2 can be suppressed because of the binding of the metal ion by chelating agents. It is proved that stabilization ability of CDTA is better than that of EDTA, and stabilization ability can be promoted by much larger amount of chelating agent addition. For the aqueous solution of H2O2 and “basic” TMAH, the decomposition rate of H2O2 is accelerated due to the increase of pH value. |
