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Performance of thin film Transistors on Unhydrogenated In-Situ Doped Polysilicon films Obtained by Solid Phase Crystallization

Published online by Cambridge University Press:  10 February 2011

K. Mourgues
Affiliation:
Groupe de Microélectronique et Visualisation, UPRESA 6076, Université de RENNES I, Campus de Beaulieu, 35042 RENNES cedex, FRANCE
F. Raoult
Affiliation:
Groupe de Microélectronique et Visualisation, UPRESA 6076, Université de RENNES I, Campus de Beaulieu, 35042 RENNES cedex, FRANCE
L. Pichon
Affiliation:
Groupe de Microélectronique et Visualisation, UPRESA 6076, Université de RENNES I, Campus de Beaulieu, 35042 RENNES cedex, FRANCE
T. Mohammed-Brahim
Affiliation:
Groupe de Microélectronique et Visualisation, UPRESA 6076, Université de RENNES I, Campus de Beaulieu, 35042 RENNES cedex, FRANCE
D. Briand
Affiliation:
Groupe de Microélectronique et Visualisation, UPRESA 6076, Université de RENNES I, Campus de Beaulieu, 35042 RENNES cedex, FRANCE
O. Bonnaud
Affiliation:
Groupe de Microélectronique et Visualisation, UPRESA 6076, Université de RENNES I, Campus de Beaulieu, 35042 RENNES cedex, FRANCE
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Abstract

Low Temperature Unhydrogenated in-situ doped polysilicon Thin Film Transistors (LTUTFT) are made through two types of four-mask aluminium gate process. Silicon layers are elaborated by a Low Pressure Chemical Vapor Deposition (LPCVD) method and crystallized by a thermal annealing. Source and drain regions are in-situ doped. An Atmospheric Pressure Chemical Vapor Deposition (APCVD) silicon dioxide ensures the gate insulation. Two structures A and B are fabricated, the difference is that for sample B the undoped/doped polysilicon layer interface is suppressed.

The structure of the polysilicon films is studied using Transmission Electron Microscopy (TEM) and Current-Voltage characteristics of both types of TFTs indicate electrical quality of the polysilicon films.

The best electrical properties are obtained with the B type TFTs: a low threshold voltage (VT=1.2V), a low subthreshold slope (0.7 V/dec), a high On/Off state current ratio (107) for a drain voltage VDS= 1V, and a very high field effect mobility (≥100 cm2 /Vs). It is worth to notice that these good results are obtained without hydrogenation.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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References

REFERENCES

1. Duhamel, N. and Loisel, B., Solid State Phenomena, Scitec Publications, vol. 37–38, p. 535546 (1994).Google Scholar
2. Wei Wu, I., Solid State Phenomena, Scitec Publications, vol. 37–38, p. 553564 (1994).Google Scholar
3. Hanna, Jun-Ichi and Shimizu, Isamu, MRS Bulletin, March, p. 3538 (1996).Google Scholar
4. Brotherton, S. D., Semicond. Sci. Technol., vol. 10, p. 721738 (1995).Google Scholar
5. Pichon, L., Raoult, F., Mourgues, K., Kis-Sion, K., Mohammed-Brahim, T. and Bonnaud, O., EMRS, Strasbourg (1996).Google Scholar
6. Briand, D., Sarret, M., Le Bihan, F., Bonnaud, O. and Pichon, L., Material Science and Technology, vol. 11, pp. 1207(1995).Google Scholar
7. Haji, L. and Joubert, P., J. Appl. Phys., vol. 75, no 8, p. 39443952 (1994).Google Scholar
8. Sze, S. M., Physics of Semiconductor Devices, Wiley, New York, 2nd Edition, p. 442 (1981).Google Scholar