TFT廠清洗製程NH4OH/DI溶液特性與監控系統相關性之研究

Relation Study between NH4OH/DI Solution Behavior and Monitor System of Clean Process in TFT Factory

林進明(Chin-Ming Lin)

指導教授 ： 李崑池

崑山科技大學/工程學院/環境工程研究所/碩士(2007年)

摘要

本研究主要進行TFT廠清洗製程NH4OH/DI溶液特性與監控系統相關性之研究，以作為製程監控參數選擇及化學品減量之依據。分別探討光電廠玻璃基板清洗製程中(在不添加過氧化氫的情形下)，清洗溶液(NH4OH/DI)NH4OH濃度與溶液pH值、導電度、氧化還原電位的關係。並以SiO2及Al2O3粉末分別模擬玻璃基板及製程中欲去除之particle，探討SiO2及Al2O3粉末濃度對於溶液中NH4+濃度、溶液pH值、導電度、氧化還原電位的影響。由實驗結果中發現當NH4OH/DI溶液中不含SiO2及Al2O3時，溶液pH值及導電度均隨NH4OH/DI濃度的減少而降低；當NH4OH/DI溶液中含有SiO2 時，溶液pH值會隨著SiO2劑量增加而減少，但溶液中的導電度則會隨著SiO2劑量的增加而增加。當NH4OH濃度為0.013%，製程溫度為50℃時，NH4OH/DI清洗溶液中SiO2的添加量約為3.5g/L時，溶液pH值會由9.27降低至9以下，導電度會由90μS/cm上升至180μS/cm，此時清洗溶液中Al2O3的表面電荷可能為正電荷，將不利於玻璃基板(SiO2)上particle(Al2O3)之去除。因此建議TFT廠在進行清洗機台NH4OH/DI溶液貯存槽製程參數監控或化學品減量時，除了監控溶液中的導電度外，應配合pH Meter監控NH4OH/DI溶液貯存槽中的溶液pH值；或建立系統有SiO2存在下之導電度與溶液pH值之關係，以作為是否添加高濃度的NH4OH溶液於NH4OH/DI溶液貯存槽之依據。

關鍵字

氧化還原電位 ； 導電度 ； 酸鹼度 ； 氧化鋁 ； 二氧化矽 ； 清洗製程 ； 玻璃基板

並列摘要

This study is mainly to establish the relationship between the solution behaviors and process monitoring variables at substrate clean process in TFT industry in order to reduce the amount of chemicals usage. The relationship between the concentration of NH4OH and solution pH values, conductivity and redox potential was studied at various dosage of SiO2 and Al2O3. The solution pH value and conductivity was increased with the increase of NH4OH concentration without the dosage of SiO2. The conductivity will be increased with the dosage of SiO2 but the solution pH values was decreased with the dosage of SiO2 at the same concentration of NH4OH. That might be due to the generation of HSiO3- resulted from the reaction of SiO2 with hydroxide ion. The results in this study will be good for finding an optimum sensor in order to reduce the chemicals dosage.

並列關鍵字

SiO2 ； Solution pH Value ； Conductivity ； Clean Process ； TFT

參考文獻

Chapman, D. L., “A contribution to the theory of electrocapillarity”, PHilosopHical magazine, 6, 475-481, 1913.

Derjaguin, B. V. and L. D. Landau.,”Theory of stability of strongly Charged lyopHobic sols and of the adhesion of strongly charged particles In solutions of electrolytes”,Acta PHysicochimca URSS, 14, 733-762, 1941.

Fair, G. M., J. C. Geyer, and D. A. Okum., “Water purification andwaste water treatment and disposal”, John Wiley and Sons：New York., 1968.

Gouy, C., ”Suy la constitution de la charge e’lectrique a’la surfaced’um e’lectrolyte”, Annals of PHysics (Pairs) Serie 4, 9, 457-468, 1910.

Hamaker, H. C.,”London-van der waals attraction between spHericalparticles”, PHysica, 4, 1058-1072, 1937.