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15 results on '"Qin, Zhiyang"'

11. Hollow Cathode Plasma (HCP) Enhanced Atomic Layer Deposition of Silicon Nitride (SiNx) Thin Films Using Pentachlorodisilane (PCDS)

Author

Su Min Hwang, Aswin L. N. Kondusamy, Qin Zhiyang, Harrison S. Kim, Jiyoung Kim, Byung Keun Hwang, Xiaobing Zhou, Michael Telgenhoff, and Jeanette Young

Abstract

Silicon nitride (SiNx) films have drawn great attention due to the wide range of applications such as passivation layer, gate dielectric, spacer, charge trap layer, and diffusion barrier [1]. Conventionally used LPCVD and PECVD for SiNx deposition have limitations in terms of conformal deposition and thickness scalability. Since plasma enhanced atomic layer deposition (PEALD) is expected to overcome these shortcomings, several research groups have reported SiNx film deposition. A number of studies on PEALD SiNx process using various chlorine-containing silicon precursors have been reported due to their ease in synthesis as well as good thermal stability [2]. Recently, PEALD SiNx film using a novel chlorosilane precursor, pentachlorodisilane (PCDS, HSi2Cl5) with NH3/N2 plasma was reported [3]. Under the NH3/N2 plasma condition, PCDS enhanced the growth rate (approximately > 20 %) compared to the hexachlorodisilane (HCDS, Si2Cl6), but still showed relatively poor wet etch resistance. Inspired the film characteristics, we propose to explore the feasibility of improving the wet etch resistance of PEALD-SiNx films using the different gas mixture for plasma. It has been reported that the wet etch rate of SiNx films has a linear relationship with the hydrogen concentration in the films [1]. Compared to NH3/N2 plasma, N2-H2 (forming gas) plasma improves the wet etch rate possibly due to less N-H and H-N-H bonds in the SiNx films [2]. Herein, PEALD SiNx films using PCDS as Si precursor and N2-H2 (10 % forming gas) plasma as the reactant were evaluated. The combination with PCDS and N2-H2 plasma showed a relatively lower (approximately < 10 %) growth rate than NH3/N2 plasma under a range of process temperatures (270−300 °C) whereas the wet etch resistance to HF acid was improved (> 1.5 nm/min, 500:1 HF). Studying these results, we suggest the effect of hydrogen on film properties such as growth rate, film composition, and wet etch resistance. [1] H.S. Kim, X. Meng, S.J. Kim, A.T. Lucero, L. Cheng, Y.C. Byun, J.S. Lee, S.M. Hwang, A.L.N. Kondusamy, R.M. Wallace, G. Goodman, A.S. Wan, M. Telgenhoff, B.K. Hwang, and J. Kim, ACS Appl. Mater. Interfaces 10, 44825 (2018). [2] X. Meng, Y.C. Byun, H.S. Kim, J.S. Lee, A.T. Lucero, L. Cheng, and J. Kim, Materials 9, 1007 (2016). [3] X. Meng, H.S. Kim, A.T. Lucero, S.M. Hwang, J.S. Lee, Y.C. Byun, J. Kim, B.K. Hwang, X. Zhou, J. Young, and M. Telgenhoff, ACS Appl. Mater. Interfaces 10, 14116 (2018). Figure 1

Published
2019

12. Ozone based high-temperature atomic layer deposition of SiO2 thin films.

Author

Hwang, Su Min, Qin, Zhiyang, Kim, Harrison Sejoon, Ravichandran, Arul, Jung, Yong Chan, Kim, Si Joon, Ahn, Jinho, Hwang, Byung Keun, and Kim, Jiyoung

Abstract

In this paper, atomic layer deposition of SiO2 thin films was investigated with Si2Cl6 and O3/O2 (400 g m−3). O3/O2 is not preferred for high-temperature (>400 °C) processes due to its lower decomposition temperature, especially in a furnace-type chamber. However, with Si oxidation test using a cold-wall chamber, we have demonstrated the reactivity of O3/O2 up to 800 °C in comparison with O2 and H2O. The ALD of SiO2 films was examined at deposition temperatures from 500 °C to 700 °C. The growth rate at 600 °C was saturated to 0.03 nm/cycle with Si2Cl6 exposure over 1.2 × 105 L. O3/O2 also showed ALD-like saturation behaviors for exposures over 2.4 × 106 L. The ALD films deposited at 600 °C exhibited relatively smooth surface roughness (<0.18 nm) and low wet etch rate (1.6 nm min−1, 500:1 HF) that are comparable with PECVD SiO2 deposited at 250 °C and LPCVD SiO2 deposited at 450 °C. [ABSTRACT FROM AUTHOR]

Published
2020
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13. Vapor-phase Surface Cleaning of Electroplated Cu Films Using Anhydrous N2H4

Author

Min, Su, Fabian, Luis, Tan, Kui, Sejoon, Harrison, N, Aswin L., Qin, Zhiyang, Chan, Yong, Veyan, Francois, Alvarez, Daniel, Spiegelman, Jeff, and Kim, Jiyoung

Abstract

Cleaning of copper surfaces is required to remove undesired surface oxidation during the interconnect fabrication process. In this work, we examined the vapor-phase cleaning of Cu surfaces using anhydrous N2H4. Gas cluster ion beam (GCIB) depth profiling and elemental analysis using XPS shows that CuxO in the Cu sample, formed after exposure to air, can be effectively reduced to Cu0 at 200 degC. By monitoring the surface chemistry using in-situ reflectance absorption infrared spectroscopy (RAIRS), we found that atomic layer deposition (ALD)-like single exposure of N2H4 at 200 degC can remove the adventitious surface contamination and, most importantly, reduce the Cu2O to metallic Cu.

Published
2019

14. Hollow Cathode Plasma (HCP) Enhanced Atomic Layer Deposition of Silicon Nitride (SiNx) Thin Films Using Pentachlorodisilane (PCDS)

Author

Min, Su, N, Aswin L., Qin, Zhiyang, Sejoon, Harrison, Meng, Xin, Kim, Jiyoung, Keun, Byung, Zhou, Xiaobing, Telgenhoff, Michael, and Young, Jeanette

Abstract

In this work, effects of NH3/N2 and N2-H2/Ar plasma gases for the growth of PEALD SiNx films using pentachlorodisilane (PCDS, HSi2Cl5) were studied using a hollow cathode PEALD system. At identical process conditions, the combination of PCDS and N2[?]H2/Ar plasma showed a relatively lower (approximately < 10 %) growth rate as compared to NH3/N2 plasma under a range of process temperatures (240[?]300 degC) whereas the wet etch resistance to HF acid was improved (> 1.6 nm/min, 500:1 HF). Using XPS and FTIR analysis, it was identified that N2[?]H2/Ar gas mixture results in a Si-rich SiNx film with less N[?]Hx bonds when compared to NH3/N2 mixture, thereby resulting in a decreased wet etch rate.

Published
2019

15. Nitrogen-doped TiO2microsheets with enhanced visible light photocatalytic activity for CO2reduction

Author

Akple, Maxwell Selase, Low, Jingxiang, Qin, Zhiyang, Wageh, S., Al-Ghamdi, Ahmed. A., Yu, Jiaguo, and Liu, Shengwei

Abstract

Nitrogen-doped anatase TiO2microsheets with 65% (001) and 35% (101) exposed faces were fabricated by the hydrothermal method using TiN as precursor in the presence of HF and HCl. The samples were characterized by scanning electron microscopy, X-ray diffraction, N2adsorption, X-ray photoelectron spectroscopy, UV-visible spectroscopy, and electrochemical impedance spectroscopy. Their photocatalytic activity was evaluated using the photocatalytic reduction of CO2. The N-doped TiO2sample exhibited a much higher visible light photocatalytic activity for CO2reduction than its precursor TiN and commercial TiO2(P25). This was due to the synergistic effect of the formation of surface heterojunctions on the TiO2microsheet surface, enhanced visible light absorption by nitrogen-doping, and surface fluorination.

Published
2015
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