Hostname: page-component-8448b6f56d-sxzjt Total loading time: 0 Render date: 2024-04-19T10:40:54.161Z Has data issue: false hasContentIssue false
  • English
  • Français

Fabrication and Characterization of Hydrogenated Amorphous Silicon Bipolar Thin Film Transistor (B-TFT)

Published online by Cambridge University Press:  21 March 2011

Yue Kuo ,
Yu Lei  and
Helinda Nominanda
Yue Kuo
Affiliation:
Thin Film Nano & Microelectronics Research Laboratory, Texas A&M University, College Station, TX, U.S.A.
Yu Lei
Affiliation:
Thin Film Nano & Microelectronics Research Laboratory, Texas A&M University, College Station, TX, U.S.A.
Helinda Nominanda
Affiliation:
Thin Film Nano & Microelectronics Research Laboratory, Texas A&M University, College Station, TX, U.S.A.
Get access

Abstract

The conventional a-Si:H thin film transistor (TFT) is a field effect transistor (FET), which has disadvantages of a low operation speed and a small current driving capability. To achieve a higher speed and larger current driving capability, a potential solution is to fabricate the a-Si:H-based bipolar thin film transistor (B-TFT). In this study, a-Si:H p-i-n junctions were prepared and studied in order to determine the proper layer thickness for good junction behaviors. B-TFTs composed of a stacked structure of n+/i/p/i/n+ were then fabricated. The complete B-TFT was made using plasma enhanced chemical vapor deposition (PECVD) to deposit all doped and undoped a-Si:H layers and SiNx dielectrics at 250°C. Reactive ion etching (RIE) and wet etching methods were used to define base and emitter regions and contacts. The I-V characteristics of the complete B-TFT were investigated. The common-emitter current gain is 3∼6, which is larger than the literature report of 2∼3. In addition, a collector current larger than the literature value was obtained. A significant current noise was observed, which may be contributed to the high series resistance of the base layer and defective junction interfaces. In this paper, process and structure influences on the a-Si:H junction and B-TFT performances are discussed.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 808: Symposium A – Amorphous and Nanocrystaline Silicon Science and Technology-2004 , 2004 , A4.7
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Flewitt, A. J. and Milne, W. I., “a-Si:H TFT Thin Film and Substrate Materials”, Amorphous Silicon Thin Film Transistors, ed. Kuo, Y., (Kluwer Academic Publishers, 2004) pp.15–69.Google Scholar
2. Nijs, J. F. and Symons, J. J., “The Use of Amorphous and Microcrystalline Silicon and Their Alloys in Bipolar Devices and Technology, Amorphous and microcrystalline semiconductor devices: materials and device physics”, ed. Kanicki, J., (Artech House, Inc., 1992) pp.563–604.Google Scholar
3. Nara, Y. and Matsumura, M., Japanese Journal of Applied Physics, 23(9), L714(1984).Google Scholar
4. Kuo, Y., Appl. Phys. Lett, 61(23), 2790–2792(1992).Google Scholar
5. Sze, S. M., Physics of Semiconductor Devices, 2nd edition, (Wiley-Interscience, 1981) pp.92.Google Scholar
6. Matsuura, H., Matsuda, A., Okushi, H., and Tanaka, K., J. Appl. Phys., 58(4), 1578–1583(1985).Google Scholar
7. Fiorini, P. and Mittiga, A., “Dark Electrical Characteristics of Amorphous n-i-n, p-i-p, p-i-n and p-n diodes”,Amorphous and microcrystalline semiconductor devices: materials and device physics, ed. Kanicki, J., (Artech House, Inc., 1992) pp.283–329.Google Scholar
8. Taur, Y. and Ning, T. H., Fundamentals of Modern VLSI Devices, (Cambridge University Press, 1998) pp.312–355.Google Scholar