The Effect of Thinning Barrier Layer on Electrodeposition of Cu2O into Anodic Aluminum Oxide

[[abstract]]本研究主要是探討如何薄化阻障層，以及對電鍍Cu2O的影響，在製備模板方面以磷酸加草酸混和溶液來製備陽極氧化鋁(Anodic aluminum oxide，AAO)。由於二次陽極氧化處理過後的AAO，其鋁片與AAO膜底部存在著阻障層，進而限制了之後作為模板電鍍金屬或半導體的應用。因此如何減薄此阻障層及了解對電鍍過程的影響是本論文的探討目標。為了研究如何讓AAO的阻障層減薄並同時了解對電鍍過程的影響，利用了三次降電壓過程處理及擴孔來薄化阻障層，藉由磷酸加草酸混和溶液、草酸溶液、硫酸溶液等三種不同溶液的降電壓來大幅減低了阻障層厚度，並同時利用電鍍Cu2O的製程來觀察厚度的影響。在電鍍Cu2O方面，我們採用脈衝電鍍和直流電鍍來做比較，發現脈衝電鍍Cu2O的填洞率比直流電鍍好很多，利用循環伏安法測出還原電位-1.4V，因而最後採用脈衝電鍍的電壓值為-1V至-1.4V，脈衝頻率為100Hz，脈衝的工作週期則介於70~75%時有較好的電鍍成果。最後再由SEM及XRD來分析電鍍於AAO孔洞裡的Cu2O。[[abstract]]This study is to explore how to achieve barrier layer thinning, as well as its impact on the plating of Cu2O into the pores of anodic aluminum oxide (AAO), which was prepared in the solution of phosphoric acid mixed with oxalic acid. As the presence of AAO barrier layer after second anodization, the electrodeposition of metal or semiconductor into the pores of AAO was limited. Therefore, it is the goal of this thesis to explore the effect of barrier layer on electroplating of metal or semiconductor into the pores, and how to thinning the barrier layer. In order to study thinning of AAO barrier layer thinning and while understanding its impact on the electroplating process, the subsequent three voltage drop processes after anodizations using solutions of phosphoric acid mixed with oxalic acid, oxalic acid and sulfuric acid solution were conducted. After each step of barrier thinning, electroplating process of Cu2O was conducted to observe the impact of previous thinning process. It is shown that pulse electrodeposition of Cu2O can fill the pores more efficiently than the DC one. The reduction potential of-1.4V for Cu2O was measured by cyclic voltammetry. Therefore, pulse voltages from -1V to-1.4V was adopted with the pulse frequency of 100Hz. The pulse duty cycle between 70 to 75% showed better results. The deposited Cu2O on the AAO template was analyzed by SEM and XRD