Hostname: page-component-848d4c4894-2xdlg Total loading time: 0 Render date: 2024-07-04T19:16:49.606Z Has data issue: false hasContentIssue false
  • English
  • Français

Two-Dimensional Amorphous Silicon Color Sensor Array

Published online by Cambridge University Press:  17 March 2011

F. Lemmi ,
M. Mulato ,
J. Ho ,
R. Lau ,
J. P. Lu  and
R. A. Street
M. Mulato
Affiliation:
Xerox Palo Alto Research Center, 3333 Coyote Hill Road, Palo Alto, CA, 94304
J. Ho
Affiliation:
Xerox Palo Alto Research Center, 3333 Coyote Hill Road, Palo Alto, CA, 94304
R. Lau
Affiliation:
Xerox Palo Alto Research Center, 3333 Coyote Hill Road, Palo Alto, CA, 94304
J. P. Lu
Affiliation:
Xerox Palo Alto Research Center, 3333 Coyote Hill Road, Palo Alto, CA, 94304
R. A. Street
Affiliation:
Xerox Palo Alto Research Center, 3333 Coyote Hill Road, Palo Alto, CA, 94304
Get access

Abstract

This paper reports on the first full realization and characterization of a two-dimensional array of amorphous silicon (a-Si:H) color sensors, addressed by integrated amorphous silicon-based thin-film transistors (TFTs). The array includes 512 × 512 pixels with 75-µm pitch, or about 340 dpi. Each pixel features a color sensor realized by a p-i-n-i-p stack of doped and undoped a-Si:H layers, and the TFT. The color sensors are made of two back-to-back p-i-n diodes, which selectively sense the illumination according to the polarity of the applied bias voltage. The sensor layers are grown on top of the TFTs to improve the array fill factor. The p-in-i-p sensor stack is mesa-isolated into single sensors to reduce cross-talk.

Images are acquired using two bias voltages and yield the red and blue/green components of the original with a good color separation. A color image is reconstructed using the information from the two images acquired. Aside from a color bias, which is expected for a two-color reconstruction, the imaging system works well. In particular, the array shows very low leakage currents, which enable a very large dynamic range and sensitivity. In the response of the array to a light pulse, the bottom thick diode ensures a fast drop in the signal after the flash, while the top thin diode exhibits some residual image lag.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 664: Symposium A – Amorphous and Heterogeneous Silicon-Based Films-2001 , 2001 , A18.1
Copyright
Copyright © Materials Research Society 2001

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. Street, R.A., Nelson, S., Antonuk, L., Perez, V., , Mendez, M.R.S. Symp. Proc. 192, p. 441 (1990).10.1557/PROC-192-441Google Scholar
2. Street, R.A., in Technology and Applications of Amorphous Silicon, ed. Street, R. A., Springer-Verlag, Heidelberg, Germany, p. 147 (2000)Google Scholar
3. Guha, S., in Technology and Applications of Amorphous Silicon, ed. Street, R. A., Springer-Verlag, Heidelberg, Germany, p. 252 (2000)Google Scholar
4. Caputo, D., Cesare, G. de, Irrora, F., Lemmi, F., Palma, F., IEEE Trans. on Electron Devices, 42, p. 835 (2000).Google Scholar
5. Lemmi, F., Street, R.A., IEEE Trans. on Electron Devices, 47, p. 2399 (2000).Google Scholar
6.BCB is a polymer-based CYCLOTENE® Resin from The Dow Chemical Company (www.dow.com/cyclotene), which is derived from B-staged bisbenzocyclobutene (BCB) monomers.Google Scholar
7. Lemmi, F., Mulato, M., Ho, J., Lau, R., Lu, J-P., Street, R.A. and Palma, F., Appl. Phys. Lett., 78, p. 1334 (2001).Google Scholar
8. Mulato, M., Ho, J., Lau, R., Lu, J.P., Street, R.A., Lemmi, F., submitted to J. Appl,. Phys.Google Scholar
9. Irrera, F., Lemmi, F., Palma, F., Diotallevi, M., MRS Symp. Proc., 507, p. 309 (1998).Google Scholar
10. Neidlinger, T., Schubert, M.B., Schmid, G., Brummack, H., MRS Symp. Proc., 420, p.147 (1996).Google Scholar