| Summary: | 碩士 === 南台科技大學 === 化學工程系 === 92 === Electroplating is a major method for IC interconnection metallic process. The electroplating method has some advantages of low cost, low toxicant, high deposition rate, high quality of the copper film morphology and simple operation system, but the major disadvantage is the fair-poor filling. In this study, we focused on the effects of the jet flow、shock wave and water-hammer effects due to cavitation phenomenon in the presence of ultrasonic irradiation and addition of additives. We expected these effects could be achieved the leveling and the superfilling of deposited copper film. Furthermore, the effect mechanisms of ultrasonic would be studied on the electrode reaction kinetics with ultrasonic irradiation.
The current density was increased with increasing of the ultrasonic irradiation power density. Compared with non-ultrasonic irradiation condition, the surface morphologies of copper electroplated films with ultrasonic irradiation were more smoother and finer. On the other hand, the ultrasonic irradiation did not affect the conductivity of electroplated films, and were similar to the theory value. In the presence of PEG, though the trench filling improved remarkably with ultrasonic irradiation, but exist voids The presence of the formalin or the mixture of 300 mg/L PEG 6000 and 1 mg/L JGB could be obtained the superfilling phenomenon with ultrasonic irradiation at power density of 21 W.
For the kinetic studied of an electrode reaction, the effect mechanism of ultrasonic had been investigated with charge transfer parameter due to Tafel equation and mass transfer parameter due to rotating disk electrode during ultrasonic irradiation. The limit current density improved with the jet flow effect due to ultrasonic irradiation compared with non-ultrasonic irradiation. Because of the exchange current density was increased, the parameters of a、b、i0 and 1-α were induced with the jet flow ultrasonic irradiation, and improved the migration of copper ions to the surface of electrode. On the other hand, the jet flow effect could reduce the thickness of diffusion layer and improved the limit density during ultrasonic irradiation. Furthermore, the surface morphologies were more smoother and finer due to the shock wave、water-hammer effects, Because of these effects could be affected directly the surface of electrode, and crack the deposites during ultrasonic irradiation. On the other hand, the superfilling could be obtained due to jet flow and shock wave effects, because of these effects could be attack the deposites on upper lip, and crack it to fall down the bottom of the trench, during ultrasonic irradiation.
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