Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-20T09:15:59.343Z Has data issue: false hasContentIssue false
  • English
  • Français

High Sensitivity of Hydrogen Sensing Through N-polar GaN Schottky Diodes

Published online by Cambridge University Press:  31 January 2011

Yu-Lin Wang ,
B.H. Chu ,
Chih-Yang Chang ,
Ke Hung Chen ,
Yu Zhang ,
Qian Sun ,
Jung Han ,
S.J. Pearton  and
F Ren
Yu-Lin Wang
Affiliation:
[email protected]
B.H. Chu
Affiliation:
[email protected], University of Florida, Gainesville, Florida, United States
Chih-Yang Chang
Affiliation:
[email protected], University of Florida, Gainesville, Florida, United States
Ke Hung Chen
Affiliation:
[email protected], University of Florida, Gainesville, Florida, United States
Yu Zhang
Affiliation:
[email protected], Yale, New Haven, Connecticut, United States
Qian Sun
Affiliation:
[email protected], Yale, New Haven, Connecticut, United States
Jung Han
Affiliation:
[email protected], Yale, New Haven, Connecticut, United States
S.J. Pearton
Affiliation:
[email protected], Univ.Florida, Materials, PO Box 116400, Gainesville, Florida, 32611, United States
F Ren
Affiliation:
[email protected], University of Florida, Chemical Engineering, Gainesville, Florida, United States
Get access

Abstract

N-polar and Ga-polar GaN grown on c-plane sapphire by a metal-organic chemical vapor deposition (MOCVD) system were used to fabricate platinum deposited Schottky contacts for hydrogen sensing at room temperature. Wurtzite GaN is a polar material. Along the c-axis, there are N-face (N-polar) or Ga-face (Ga-polar) orientations on the GaN surface. The Ohmic contacts were formed by lift-off of e-beam deposited Ti (200 Å)/Al (1000 Å)/Ni (400 Å)/Au (1200 Å). The contacts were annealed at 850°C for 45 s under a flowing N2 ambient. Isolation was achieved with 2000 Å plasma enhanced chemical vapor deposited SiNx formed at 300°C. A 100 Å of Pt was deposited by e-beam evaporation to form Schottky contacts. After exposure to hydrogen, Ga-polar GaN Schottky showed 10% of current change, while the N-polar GaN Schottky contacts became fully Ohmic. The N-polar GaN Schottky diodes showed stronger and faster response to 4% hydrogen than that of Ga-polar GaN Schottky diodes. The abrupt current increase from N-polar GaN Schottky exposure to hydrogen was attributed to the high reactivity of the N-face surface termination. The surface termination dominates the sensitivity and response time of the hydrogen sensors made of GaN Schottky diodes. Current-voltage characteristics and the real-time detection of the sensor for hydrogen were investigated. These results demonstrate that the surface termination is crucial in the performance of hydrogen sensors made of GaN Schottky diodes.

Keywords

III-Velectronic materialsensor
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1202: Symposium I – III-Nitride Materials for Sensing, Energy Conversion and Controlled Light-Matter Interactions , 2009 , 1202-I06-06
Copyright
Copyright © Materials Research Society 2010

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 Baranzahi, A., Spetz, A. Lloyd and Lundström, I., Reversible hydrogen annealing of metal-oxide-silicon carbide devices at high temperatures, Appl. Phys. Lett. 67, 3203 (1995).Google Scholar
2 Spetz, A. Lloyd, Unéus, L., Svenningstorp, H., Tobias, P., Ekedahl, L.-G., Larsson, O., Göras, A., Savage, S., Harris, C., Mårtensson, P., Wigren, R., Salomonsson, P., Häggendahl, B., Ljung, P. and Mattsson, M. and Lundström, I., SiC Based Field Effect Gas Sensors for Industrial Applications, Phys. Status Solidi A 185, 15 (2001).Google Scholar
3 Luther, B.P., Wolter, S.D. and Mohney, S.E., High temperature Pt Schottky diode gas sensors on n-type GaN, Sens. Actuat. B 56, 164 (1999).Google Scholar
4 Schalwig, J., Muller, G., Ambacher, O. and Stutzmann, M., Group-III-Nitride Based Gas Sensing Devices, Phys. Status Solidi A 185, 39 (2001).Google Scholar
5 Schalwig, J., Muller, G., Eickhoff, M., Ambacher, O. and Stutzmann, M., Gas sensitive GaN/AlGaN-heterostructures, Sens. Actuat. B 87, 425 (2002).Google Scholar
6 Schalwig, J., Müller, G., Karrer, U., Eickhoff, M., Ambacher, O., Stutzmann, M., Görgens, L. and Dollinger, G., Hydrogen response mechanism of Pt-GaN Schottky diodes, Appl. Phys. Lett. 80, 1222 (2002).Google Scholar
7 Eickhoff, M., Schalwig, J., Steinhoff, G., Weidmann, O., Gorgens, L., Neuberger, R., Hermann, M., Baur, B., Muller, G., Ambacher, O. and Stutzmann, M., Electronics and sensors based on pyroelectric AlGaN/GaN heterostructures-Part B: Sensor applications, Phys. Status Solidi C 0, 1908 (2003).Google Scholar
8 Kim, J., Ren, F., Gila, B., Abernathy, C.R. and Pearton, S.J., Reversible barrier height changes in hydrogen-sensitive Pd/GaN and Pt/GaN diodes, Appl. Phys. Lett. 82, 739 (2003).Google Scholar
9 Kim, J., Gila, B., Chung, G.Y., Abernathy, C.R., Pearton, S.J. and Ren, F., Hydrogen-sensitive GaN Schottky diodes, Solid-State Electron. 47, 1069 (2003).Google Scholar
10 Wang, H.T., Kang, B.S., Ren, F., Fitch, R.C., Gillespie, J., Moser, N., Jessen, G., Dettmer, R., Gila, B.P., Abernathy, C.R. and Pearton, S.J., Comparison of gate and drain current detection of hydrogen at room temperature with AlGaN/GaN high electron mobility transistors, Appl. Phys. Lett. 87, 172101–1 (2005).Google Scholar
11 Ambacher, O., Smart, J., Shealy, J. R., Weimann, N. G., Chu, K., Murphy, M., Schaff, W. J., Eastman, L. F., Dimitrov, R., Wittmer, L., Stutzmann, M., Reiger, W., Hilsenbeck, J., Two-dimensional electron gases induced by spontaneous and piezoelectric polarization charges in N- and Ga-face AlGaN/GaN heterostructures, J. Appl. Phys. 85, 3222 (1999).Google Scholar
12 Starke, U., Sloboshanin, S., Tautz, F. S., Seubert, A., Schaefer, J. A., Polarity, Morphology and Reactivity of Epitaxial GaN Films on A1203(0001), Phys. Status Solidi A. 177, 5 (2000).Google Scholar
13 Northrup, J. E., Neugebauer, J., Strong affinity of hydrogen for the GaN(000-1) surface: Implications for molecular beam epitaxy and metalorganic chemical vapor deposition, Appl. Phys. Lett. 85, 3429 (2004).Google Scholar
14 Mayumi, M., Satoh, F., Kumagai, Y., Takemoto, K., Koukitu, A., Influence of Polarity on Surface Reaction between GaN{0001} and Hydrogen, Phys. Status Solidi B. 228, 537 (2001).Google Scholar
15 Wang, Yu-Lin, Ren, F., Zhang, U., Sun, Q., Yerino, C. D., Ko, T. S., Cho, Y. S., Lee, I. H., Han, J., Pearton, S. J., Appl. Phys. Lett. 94, 212108–1 (2009).Google Scholar
16 Sun, Q., Cho, Y. S., Kong, B. H., Cho, H. K., Ko, T. S., Yerino, C. D., Lee, I.-H., and Han, J., N-face GaN growth on c -plane sapphire by metalorganic chemical vapor deposition, J. Cryst. Growth 311, 2948 (2009).Google Scholar
17 Sun, Q., Cho, Y. S., Lee, I.-H., Han, J., Kong, B. H., and Cho, H. K., Nitrogen-polar GaN growth evolution on c-plane sapphire, Appl. Phys. Lett. 93, 131912–1 (2008).Google Scholar
18 Miyoshi, M., Kuraoka, Y., Asai, K., Shibata, T., Tanaka, M., Electrical characterization of Pt/AlGaN/GaN Schottky diodes grown using AlN template and their application to hydrogen gas sensors, J. Vac. Sci. Technol. B, 25, 1231 (2007).Google Scholar
19 Tsai, Y. Y., Lin, K. W., Chen, H. I., Liu, I. P., Hung, C. W., Chen, T. P., Tsai, T. H., Chen, L. Y., Chu, K. Y., Liu, W. C., Hydrogen sensing properties of a Pt-oxide-GaN Schottky diode, J. Appl. Phys. 104, 024515–1 (2008).Google Scholar
20 Shackelford, J. F., Alexander, W., Park, J. S., CRC Materials Science and Engineering handbook, second edition, CRC Press Inc.S-117., Boca Raton, FL (1992).Google Scholar