Browsing by Author "Feng, Hsien-Ping"

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Behavior of copper removal by CMP and its correlation to deposit structure and impurity content
(2008)
Feng, Hsien-Ping
;
Lin, Jeng-Yu
;
Cheng, Ming-Yung
;
Wang, Yung-Yun
;
Wan, Chi-Chao
Knowledge of the removal behaviors of various electroplated copper films during chemical mechanical polishing (CMP) is important for thickness control and defect generation. In this paper, we investigate the effect of current density and impurities incorporated in blanket and pattern wafer by potentiodynamic polarization method, X-ray diffraction, and secondary ion mass spectroscopy. Defect count was decided by the optical scan method and scanning electron microscopy reviewing. Removal rate and corroded pits were found to decrease with increasing (111)/(200) ratio because (111), the close-packed plane of the face-centered cubic structure, has strong chemical resistance during polishing. Furthermore, incorporated impure atoms, such as carbon, chloride, and sulfur, tend to weaken grain boundaries to generate more corroded pits but do not affect removal rate. Besides, geometric constraint induces concentrated impurities to restrict copper grain growth and induce fast oxide growth rate, resulting in high dishing performance. (c) 2007 The Electrochemical Society.
Effects of direct current and pulse-reverse copper plating incubation behavior of self-annealing
(2010-10-01)
Cheng, Min-Yuan
;
Chen, Kei-Wei
;
Liu, Tzeng-Feng
;
Wang, Ying-Lang
;
Feng, Hsien-Ping
This study investigates spontaneous microstructural evolution in electroplated Cu films with various plating current densities involving direct current and pulse-reverse waveforms and various possible driving forces. Studies have explained the grain growth and resistivity decrease during the self-annealing of as-deposited Cu film, but the incubation behavior of self-annealing under various direct current and pulse-reverse current waveforms at a certain film thickness is unknown. In this study, it was found that pulse-reverse current retards the incubation behavior more significantly than does direct current. According to the measurements of resistivity, stress, and secondary ion mass spectrometer, the large stress difference between the initial and critical values and the low impurity content of pulse-reverse current postponed the incubation, and led to a slow self-annealing rate. The combination of the stress difference and the impurity effect explains the incubation behavior of self-annealing under various plating current densities. The resistivity and X-ray diffraction results suggest that stress is the primary driving force that dramatically speeds up grain growth above the critical stress, and that high current density with a rapid grain growth rate enhances the (200) texture for strain energy minimization in electroplated Cu film. (C) 2010 Published by Elsevier B.V.
Effects of direct current and pulse-reverse copper plating incubation behavior of self-annealing
(2010-10-01)
Cheng, Min-Yuan
;
Chen, Kei-Wei
;
Liu, Tzeng-Feng
;
Wang, Ying-Lang
;
Feng, Hsien-Ping
This study investigates spontaneous microstructural evolution in electroplated Cu films with various plating current densities involving direct current and pulse-reverse waveforms and various possible driving forces. Studies have explained the grain growth and resistivity decrease during the self-annealing of as-deposited Cu film, but the incubation behavior of self-annealing under various direct current and pulse-reverse current waveforms at a certain film thickness is unknown. In this study, it was found that pulse-reverse current retards the incubation behavior more significantly than does direct current. According to the measurements of resistivity, stress, and secondary ion mass spectrometer, the large stress difference between the initial and critical values and the low impurity content of pulse-reverse current postponed the incubation, and led to a slow self-annealing rate. The combination of the stress difference and the impurity effect explains the incubation behavior of self-annealing under various plating current densities. The resistivity and X-ray diffraction results suggest that stress is the primary driving force that dramatically speeds up grain growth above the critical stress, and that high current density with a rapid grain growth rate enhances the (200) texture for strain energy minimization in electroplated Cu film. (C) 2010 Published by Elsevier B.V.