In this study, copper indium selenide (CIS) films were deposited by pulsed electrodeposition with multi potentials to control the atomic ratio of the CIS film and improve the deposition uniformity. It was found that smaller duty cycle and pulsed period enhanced the cathodic current due to ion replenishment. The results show that the Cu=In ratio was significantly influenced by reverse voltage of pulsed electrodeposition. The uniformity of the CIS films can be improved by proper reverse voltage. The deposition rate did not decrease in direct proportion to the duty cycle because the plating current was enhanced by the pulse effect. The pulsed deposited CIS film with optimized composition show smaller grain size, smoother microstructure, and less secondary phase than constant deposited film.

Bis-͑3-sodiumsulfopropyl disulfide͒ ͑SPS͒ is a well-known accelerator used to promote "bottom-up filling" in the semiconductor copper ͑Cu͒ electroplating process. However, the gap-filling capability and the defect performance of Cu electroplating are impacted as the SPS molecules are decomposed or oxidized. In this study, by-products generated from SPS decomposition and oxidation were identified and quantized using mass spectroscopy. It was found that 1,3-propanedisulfonic acid ͑PDS͒ was the most stable species among the SPS by-products. The PDS concentration increased with the increasing surface area of immersed Cu metals. The relationship between the consumption rate of SPS and the generation rate of PDS with different surface areas of Cu metals was particularly investigated. Furthermore, an equivalent circuit was developed and then examined using electrochemical impedance spectroscopy to characterize the properties of the aged bath with the decomposition of SPS.

In this study, copper indium selenide (CIS)

In this study, copper indium diselenide (CIS) films were synthesized from electrodeposited Cu-Se-In-Se precursors by three step annealing. The Se layer between Cu and In layer was grown to prevent the formation of Cu/In compound. The Cu-Se precursors were first annealed to grow uniform and conductive Cu2Se surface. After deposition of the four layers precursors, two steps annealing was employed to form Cu2Se-In2Se3 precursors. Transforming Cu2Se-In2Se3 to CIS required less thermal energy. Therefore, high quality CIS film can be synthesized by two steps annealing due to its high crystallinity. The properties of the CIS films were characterized by scanning electron microscopy (SEM), X-ray Diffraction (XRD), and Raman Spectra.

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