超声波对Ta/SiO2/Si基板置换活化法化学镀铜的影响

Effect of Ultrasonic on Electroless Copper Deposition on Ta/SiO2/Si Substrate by Displacement Activation Method

摘要:

采用置换活化法，以PdCl2/BOE/HNO3溶液对Ta/SiO2/Si基板进行活化，然后在基板上成功实现化学镀Cu薄膜。应用场发射扫描电子显微镜(FESEM)、X射线衍射(XRD)等方法，研究了活化时间及超声波对化学镀Cu薄膜表面形貌和结构的影响。结果表明，在化学镀Cu过程中没有引入超声波时，随着活化时间由30 s增加到150 s，Cu膜覆盖率逐渐降低；在引入超声波以后，随着活化时间的增加，Cu膜覆盖率始终很高。XRD分析表明，引入超声波以后，Cu(111)和(200)峰的衍射强度明显增加，当活化时间为60 s时，Cu(111)和(200)峰的强度比I(111)/I(200)达到4.53。对具有沟槽的Ta/SiO2/Si基板进行化学镀Cu的结果表明，引入超声波，可以明显改善对沟槽的填充效果

Abstract:

Electroless copper deposition was performed by activation of Ta/SiO2/Si substrates using PdCl2/BOE/HNO3 displacement solution. Field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD) were employed to investigate the effects of activation time and ultrasonic on surface morphology and structure of electrolessly deposited copper films. The results show that the coverage of copper films decreased gradually with the activation time increasing from 30 s to 150 s when the plating progressed without ultrasonic, while the high coverage of copper films was held with the activation time increasing when the ultrasonic was involved. The analysis of XRD indicates that the diffraction intensity of Cu (111) and (200) orientation increased obviously after the ultrasonic was introduced. When the activation time was 60 s, the diffraction intensity ratio of Cu (111) orientation to (200) orientation (I(111)/I(200)) was 4.53. The results of electroless Cu deposition on Ta/SiO2/Si substrates with trench patterns show that the presence of ultrasonic in electroless Cu plating can remarkably improve the effect of filling in trenches