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Characterization of nGaAs-Au Schottky Diodes as Grating Coupled Photodetectors

Published online by Cambridge University Press:  25 February 2011

Kannan Krishnaswami
Affiliation:
University Of Massachusetts at Lowell, Department of Physics, Lowell, MA-01854.
A. S. Karakashian
Affiliation:
University Of Massachusetts at Lowell, Department of Physics, Lowell, MA-01854.
C. Wong
Affiliation:
University Of Massachusetts at Lowell, Department of Physics, Lowell, MA-01854.
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Abstract

Using holography and wet chemical etching, a grating of period 450nm and depth of 15nm was fabricated on a n-type GaAs substrate having a doping of 1016 cm−3. A 30 nm layer of Au was deposited on the substrate forming a Schottky contact. The ohmic back contact is an alloy of Ni, Au and Ge. These devices were optically and electrically characterized.

Optical characterization was done using a polarized 632.8 nm HeNe laser. Reflectivity measurements for complete angular scans with output currents were determined. It was observed that as reflectivity dropped to a minimum, at a specific incident angle, the output current peaked. This was attributed to excitation of surface plasma oscillations in the grating, allowing greater photon absorption in the depletion region. This was observed only when the incident electric field was p-polarized and normal to the orientation of the grating, thus satisfying the surface plasma resonance conditions.

Under the above conditions, it was observed that in a grating coupled photodetector a higher quantum efficiency can be achieved.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

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References

REFERENCES

[1] Teng, Y.Y. and Stern, E.A., Physical Review Letters 19, 511, (1967).Google Scholar
[2] Bjork, R.H., Teng, Y.Y. and Karakashian, A.S., Physics Letters 37A, 27, (1971).Google Scholar
[3] Bjork, R.H., Karakashian, A.S. and Teng, Y.Y., Physical Review B9, 1934, (1974).Google Scholar
[4] Karakashian, A.S., Physics Letters 85A, 463, (1981).Google Scholar
[5] Derov, J., Teng, Y.Y. and Karakashian, A.S., Physics Letters 95a, 197, (1983).Google Scholar
[6] Brueck, S.R.J., Diadiuk, V., Jones, T. and Length, W., Applied Physics Letters 46, 915, (1985).Google Scholar
[7] Berthold, K., Beinstingl, W., Berger, R. and Gornik, E., Applied Physics Letters 48, 526, (1986).Google Scholar
[8] Yamashita, M. and Tsuji, M., Journal Of The Physical Society Of Japan 52, 2462, (1983).Google Scholar
[9] Rahman, M., Karakashian, A.S. and Broude, S., Journal Of Applied Optics 66, 438, (1989).Google Scholar
[10] Kou, E.F.Y. and Tamir, T., Applied Optics 27, 4098, (1988).Google Scholar
[11] Rahman, M., Karakashian, A.S., Broude, S. and Gladden, D., Applied Optics 30, 2935, (1991).Google Scholar
[12] Zhou, Shu-Tong, Lin, Zong-Qi and Chang, William S.C., Applied Optics 20, 1270, (1981).Google Scholar
[13] Missous, M., Rhoderick, E.H., Woolf, D.A. and Wilkes, S.P., Semiconductor Science & Technology 7(2), 218 (1992).Google Scholar