Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-17T18:01:43.903Z Has data issue: false hasContentIssue false

Amorphous Silicon Vertical Thin Film Transistor for High Density Integration

Published online by Cambridge University Press:  01 February 2011

Isaac Chan
Affiliation:
Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
Arokia Nathan
Affiliation:
Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
Get access

Abstract

This paper presents a fabrication process for vertical thin film transistors (VTFT) based on hydrogenated amorphous silicon (a-Si:H) technology. This process yields VTFTs with an ON/OFF ratio of 105 and a leakage current of the order of 10-13A for a channel length of 1 μm. The device structure, because of significant undercutting formed after dry-etch process (reactive ion etching or RIE), has a channel profile that is skewed as opposed to vertical. This serves to compromise the structural integrity and the electrical performance of the device. Therefore, an anisotropic dry-etch process for this channel profile is being developed. It is found that a CF4/20%H2 gas mixture yields a sharp vertical sidewall profile. In addition, a modified masking process has been developed to produce a rectangular photoresist profile so as to achieve an anisotropic etch profile for the channel region. The effects of the photoresist geometry on the anisotropic dry-etch process will be discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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

1. Uchida, Y., Nara, Y., and , Matsumura, IEEE Electron Device Letters EDL-5, 105 (1984).Google Scholar
2. Coburn, J. W. and Winters, H. F., J. Vac. Sci. Technol. 16, 391 (1979).Google Scholar
3. Lehmann, H. W. and Widmer, R., J. Vac. Sci. Technol. 17, 1177 (1980).Google Scholar
4. Light, R. W. and Bell, H. B., J. Electrochem. Soc. 130, 1567 (1983).Google Scholar