Hostname: page-component-848d4c4894-8kt4b Total loading time: 0 Render date: 2024-06-30T22:33:02.802Z Has data issue: false hasContentIssue false

Characteristics of a-Si Pixel Arrays for Radiation Imaging

Published online by Cambridge University Press:  21 February 2011

I. Fujieda
Affiliation:
Xerox Palo Alto Research Center, 3333 Coyote Hill Rd. Palo Alto, CA 94304
S. Nelson
Affiliation:
Xerox Palo Alto Research Center, 3333 Coyote Hill Rd. Palo Alto, CA 94304
R. A. Street
Affiliation:
Xerox Palo Alto Research Center, 3333 Coyote Hill Rd. Palo Alto, CA 94304
R. L. Weisfield
Affiliation:
Xerox Palo Alto Research Center, 3333 Coyote Hill Rd. Palo Alto, CA 94304
Get access

Abstract

Two-dimensional a-Si photodiode arrays with the a-Si TFT readout scheme were fabricated. Some performance characteristics were investigated for detecting visible light, X-ray and γ ray. Arrays of 64×40 1mm2-pixels have good uniformity with ± 1 % in linearity variation, ± 10 % dark current variation and ± 5 % sensitivity variation. The cross-talk between adjacent pixels was found to be negligible so that the intrinsic spatial resolution was determined entirely by the pixel size. Due to the high resistivity of a-Si photodiodes and TFTs, charges generated by pulsed light illumination were retained in photodiodes for a long period of time. This enables the accumulation-mode operation for detecting low-intensity light, where only one image is obtained over a long integration time. An encapsulated Co-57 source (3 μ.Ci) was successfully imaged with 5 sec integration. Alternatively, the array can be operated by the cine-mode for detecting high-intensity light, where a number of images are obtained successively.

Type
Research Article
Copyright
Copyright © Materials Research Society 1991

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. Guang-Pu, Wei, Okamoto, H. and Hamakawa, Y., Jpn. J. Appl. Phys. 24, 1105 (1985).Google Scholar
2. Mochiki, K., Hasegawa, K. and Namatame, S., Nucl. Instr. and Meth. A273, 640 (1988).Google Scholar
3. Perez-Mendez, V., Cho, G., Fujieda, I., Kaplan, S. N., Qureshi, S. and Street, R. A., MRS Symp. Proc. 149, 621 (1989).Google Scholar
4. Ito, H., Matsubara, S., Takahashi, T., Shimada, T. and Takeuchi, H., Jpn. J. Appl. Phys. 28, L1476 (1989).Google Scholar
5. Street, R.A., Nelson, S., Antonuk, L. and Perez-Mendez, V., MRS Symp. Proc. 192, 441 (1990).Google Scholar
6. Antonuk, L.E., Kim, C.W., Boudry, J., Yorkston, J., Longo, M.J. and Street, R.A., to be published in IEEE Trans. Nuc. Sci. NS-38 (1991).Google Scholar
7. Fujieda, I., Cho, G., Drewery, J., Gee, T., Jing, T., Kaplan, S. N., Perez-Mendez, V., Wildermuth, D. and Street, R. A., to be published in IEEE Trans. Nuc. Sci. NS–38 (1991).Google Scholar
8. Thompson, M.J., MRS Symp. Proc. 70, 613 (1986).Google Scholar