Ta/Ta2O5/Cu结构制备及应用性能研究

Fabrication and Performance of Flat MIM Capacitors with Ta/Ta2O5/Cu Structure

摘要:

介绍了以Ta/Ta₂O₅/Cu为结构的平板MIM电容器的制备方法和性能测试,探究金属Cu直接作为钽电解电容器阴极层的可行性。通过阳极氧化法在钽箔表面制备非晶态的Ta₂O₅薄膜,以化学镀铜、磁控溅射镀铜两种镀铜工艺制备Ta/Ta₂O₅/Cu结构,并对所得结构进行结构表征和性能测试。实验结果表明:不同镀铜方式制备的Ta/Ta₂O₅/Cu结构在电学性能测试过程中都没有表现出电容特性,正负极之间的电阻仅有0.7Ω；以金属Cu直接作为钽电容器的阴极层会导致金属铜在测试过程中被氧化成铜离子从而进入Ta₂O₅介质层中,进而导致Ta₂O₅的击穿,因此金属铜不适合直接作为钽电容的阴极层。

Abstract:

This study explored the feasibility of employing metallic copper (Cu) as the cathode layer in tantalum electrolytic capacitors. The focus was on fabrication methods and performance testing of flat metal-insulator-metal (MIM) capacitors with a Ta/Ta₂O₅/Cu structure. An amorphous Ta₂O₅ thin film was deposited on Ta foil surfaces via anodization. Two Cu deposition techniques, namely chemical Cu plating and magnetron sputtering, were utilized to create the Ta/Ta₂O₅/Cu structures. These structures were subjected to extensive characterization and performance evaluation. The experimental results demonstrate the absence of capacitive characteristics in the Ta/Ta₂O₅/Cu structures fabricated via different Cu deposition methods during electrical performance testing, the resistance measured between the positive and negative electrodes was only 0.7Ω. And direct utilization of metallic Cu as the cathode layer in Ta capacitors leads to the oxidation of Cu into copper ions during the testing process, subsequently infiltrating the Ta₂O₅ dielectric layer and causing the breakdown of Ta₂O₅. Thus, it can be concluded that metallic Cu is unsuitable as a direct cathode layer in Ta capacitors.