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Dependance of Ionic Polarity in Semiconductor Junction Interface

반도체 접합계면이 가스이온화에 따라 극성이 달라지는 원인

  • Oh, Teresa (Division of Semiconductor Engineering, Cheongju University)
  • Received : 2018.03.28
  • Accepted : 2018.06.01
  • Published : 2018.06.30

Abstract

This study researched the reasons for changing polarity in accordance with junction properties in an interface of semiconductors. The contact properties of semiconductors are related to the effect of the semiconductor's device. Therefore, it is an important factor for understanding the junction characteristics in the semiconductor to increase the efficiency of devices. For generation of various junction properties, carbon-doped silicon oxide (SiOC) was deposited with various argon (Ar) gas flow rates, and the characteristics of the SiOC was varied based on the polarity in accordance with the Ar gas flows. Tin-doped zinc oxide (ZTO) as the conductor was deposited on the SiOC as an insulator to research the conductivity. The properties of the SiOC were determined from the formation of a depletion layer by the ionization reaction with various Ar gas flow rates due to the plasma energy. Schottky contact was good in the condition of the depletion layer, with a high potential barrier between the silicon (Si) wafer and the SiOC. The rate of ionization reactions increased when increasing the Ar gas flow rate, and then the potential barrier of the depletion layer was also increased owing to deficient ions from electron-hole recombination at the junction. The dielectric properties of the depletion layer changed to the properties of an insulator, which is favorable for Schottky contact. When the ZTO was deposited on the SiOC with Schottky contact, the stability of the ZTO was improved by the ionic recombination at the interface between the SiOC and the ZTO. The conductivity of ZTO/SiOC was also increased on SiOC film with ideal Schottky contact, in spite of the decreasing charge carriers. It increases the demand on the Schottky contact to improve the thin semiconductor device, and this study confirmed a high-performance device owing to Schottky contact in a low current system. Finally, the amount of current increased in the device owing to ideal Schottky contact.

반도체소자의 접합특성에 따라서 분극의 특성이 달라지는 원인을 조사하였다. 반도체소자의 접합특성은 최종적인 반도체소자의 효율과 관련되기 때문에 중요한 요소이며, 효율을 높이기 위해서는 반도체접합 특성을 이해하는 것은 매우 중요하다. 다양한 성질의 접합을 얻기위하여 n형의 실리콘 위에 절연물질인 carbon doped silicon oxide (SiOC) 박막을 증착하였으며, 아르곤 (Ar) 유량에 따라서 반도체기판의 특성이 달라지는 것을 확인하였다. 전도체인 tin doped zinc oxide (ZTO) 박막을 절연체인 SiOC 위에 증착하여 소자의 전도성을 살펴보았다. SiOC 박막의 특성은 플라즈마에 의하여 이온화현상이 일어날 때 Ar 유량에 따라서 이온화되는 경향이 달라지면서 반도체 계면에서의 공핍현상이 달라졌으며, 공핍층 형성이 많이 일어나는 곳에서 쇼키접합 특성이 잘 형성되는 것을 확인하였다. 아르곤 가스의 유량이 많은 경우 이온화 반응이 많이 일어나고 따라서 접합면에서 전자 홀쌍의 재결합반응에 의하여 전하들이 없어지게 되면 절연특성이 좋아지고 공핍층의 전위장벽이 증가되며, 쇼키접합의 형성이 유리해졌다. 쇼키접합이 잘 이루어지는 SiOC 박막에서 ZTO를 증착하였을 때 SiOC와 ZTO 사이의 계면에서 전하들이 재결합되면서 전기적으로 안정된 ZTO 박막을 형성하고, ZTO의 전도성이 증가되었다. 두께가 얇은 반도체소자에서 흐르는 낮은 전류를 감지하기 위해서는 쇼키접합이 이루어져야 하며, 낮은 전류만으로도 전기신호의 품질이 우수해지고 또한 채널층인 ZTO 박막에서의 전류의 발생도 많아지는 것을 확인하였다.

Keywords

References

  1. Young Joon Cho, Hyo Sik Chang, Ju Yeon Choi, "Comparison of Methods to Remove the Boron Rich Layer Formed at Boron Doping Process for c-Si Solar Cell Applications," Transactions on Electrical and Electronic Materials, vol. 28, no. 10, pp. 665-669, 2015. DOI: https://doi.org/10.4313/JKEM.2015.28.10.665
  2. In Hwan Yeo, Hae Sung Cho, Ju Eok Park, Donggun Lim, Jun Hee Kim, "Optimizing of Diffusion Condition in Spin on Doping for c-Si Solar Cell,"Transactions on Electrical and Electronic Materials, vol. 26. no. 5, pp. 410-414, 2013. DOI: https://doi.org/10.4313/JKEM.2013.26.5.410
  3. Yuta Miura, Takashi Nishida, Masahiro Echizen, Yasuaki Ishikawa, Kiyoshi Uchiyama, and Yukiharu Uraoka, "Low-Operating-Voltage Solution-Processed InZnO Thin-Film TransistorsUsing High-k $SrTa_2O_6LiLu_1$", Japanese Journal of Applied Physics, vol. 51, pp. 03CB05, 2012. DOI: https://doi.org/10.7567/JJAP.51.03CB05
  4. Teresa. Oh, "Tunneling Condition at High Schottky Barrier and Ambipolar Transfer Characteristics in Zinc Oxide Semiconductor Thin Film Transistor", Materials Research Bulletin, Vol 77, pp. 1-7, 2016. DOI: https://doi.org/10.1016/j.materresbull.2015.11.038
  5. Kyonghwan Oh and Oh-Kyong Kwon, "Threshold-Voltage-Shift Compensation and Suppression Method Using Hydrogenated Amorphous Silicon Thin-Film Transistors for Large Active Matrix Organic Light-Emitting Diode Displays", Japanese Journal of Applied Physics, vol. 51, pp. 03CD01, 2012. DOI: https://doi.org/10.7567/JJAP.51.03CD01
  6. T. Oh and C. H. Kim "Study on Characteristic Properties of Annealed SiOC Film Prepared by Inductively Coupled Plasma Chemical Vapor Deposition", IEEE Trans. Plasma Science, vol. 38, pp. 1598-1602, 2010. DOI: https://doi.org/10.1109/TPS.2010.2049665
  7. John Robertson, Robert M. Wallace, "High-K materials and metal gates for CMOS applications", Materials Science and Engineering R, vol. 88, pp. 1-41. 2015. DOI: https://doi.org/10.1016/j.mser.2014.11.001
  8. Narendra Kumar, Satyendra Kumar, Jitendra Kumar and Siddhartha Pandaa, "Investigation of Mechanisms Involved in the Enhanced Label Free Detection of Prostate Cancer Biomarkers Using Field Effect Devices", Journal of The Electrochemical Society, vol. 164, no. 9, pp. B409-B416, 2017. DOI: https://doi.org/10.1149/2.0541709jes
  9. T. Oh and C. K. CHoi "Comparison between SiOC thin film fabricated by using plasma enhance chemical vapor deposition and $SiO_2$ thin film by using fourier transform infrared spectroscopy", Journal of the Korean Physical Society, vol. 56, pp. 1150-1155, 2010. DOI: https://doi.org/10.3938/jkps.56.1150
  10. Tae Eun Park, Dong Chan Kim, Bo Hyun Kong and Hyung Koun Cho, "Structural and potical properties of ZnO thin films grown by RF magnetron sputtering on Si substrates", Journal of the Korean Physical Society, vol. 45, pp. S697-S700, 2004.