Investigation of Structural, Optical and Electrical Properties of Al0.3Ga0.7N/GaN HEMT Grown by MOCVD

Year 2020, , 687 - 696, 01.09.2020

Ömer Akpınar , Ahmet Kürşat Bilgili Mustafa Kemal Öztürk , Süleyman Özçelik , Ekmel Özbay

https://doi.org/10.2339/politeknik.583898

Abstract

In this study, Al_0.3Ga_0.7N/GaN
high electron mobility transistor (HEMT) structure is investigated grown over
c- oriented sapphire substrate by using Metal Organic Chemical Vapor Deposition
(MOCVD) method. Optical, morphological and electrical characteristics of this
structure are determined by X-ray diffraction (XRD), Photoluminecanse (PL),
Ultraviolet (UV-Vis.), Atomic Force Microscopy (AFM) and Hall- Resistivity
measurements. By using XRD method, 2θ, Full Width at Half Maximun (FWHM),
lattice parameters, crystallite size, strain, stress and dislocation values are
calculated on symmetric and asymmetric planes. Direct band gap of GaN is
determined by PL measurements as 3.24 eV. It is seen that conduction of AlGaN
layer starts at 360 nm in UV-Vis. In Hall-Resistivity measurements, it is
noticed that carrier density of HEMT structure is not effected by temperature
and mobility value is high. Carrier density and mobility values are determined
as 5.82x10¹⁵ 1/cm³ and 1198 cm²/Vs at room
temperature respectively. At the lowest temperature point (25 K) they are
calculated as 5.19x10¹⁵ 1/cm³ and 6579 cm²/Vs,
respectively.

Keywords

HEMT, XRD, Strain, Stress

Supporting Institution

Presidency Strategy and Budget Directorate

Project Number

2016K121220

Thanks

This work was supported by the Presidency Strategy and Budget Directorate (Grants Numbers: 2016K121220).

Investigation of Structural, Optical and Electrical Properties of Al0.3Ga0.7N/GaN HEMT Grown by MOCVD

Abstract

In this study, Al_0.3Ga_0.7N/GaN
high electron mobility transistor (HEMT) structure is investigated grown over
c- oriented sapphire substrate by using Metal Organic Chemical Vapor Deposition
(MOCVD) method. Structural, optical, morphological and electrical
characteristics of this structure are determined by X-ray diffraction (XRD), Photoluminescence (PL), Ultraviolet (UV-Vis.), Atomic Force Microscopy
(AFM) and Hall- Resistivity measurements. By using XRD method, 2θ, Full Width
at Half Maximun (FWHM), lattice parameters, crystallite size, strain, stress
and dislocation values are calculated on symmetric and asymmetric planes.
Direct band gap of GaN is determined by PL measurements as 3.24 eV. It is seen
that conduction of AlGaN layer starts at 360 nm in UV-Vis. In Hall-Resistivity
measurements, it is noticed that carrier density of HEMT structure is not
effected by temperature and mobility value is high. Carrier density and
mobility values are determined as 5.82x10¹⁵ 1/cm³ and
1198 cm²/V.s at room temperature, respectively. At the lowest temperature
point (25 K) they are calculated as 5.19x10¹⁵ 1/cm³ and
6579 cm²/Vs, respectively.

Keywords

HEMT, XRD, Hall, strain, stress

Project Number

2016K121220

References

• 1. Yildirim R., Yavuzcan H.G., Celebi F.V. and Gokrem L., "Temperature dependent Rolletti stability analysis of GaN HEMT", Optoelectronics and Advanced Materials-Rapid Communications, 3(8): 781-786, (2009).
• 2. Gokrem L., Celebi F.V. and R. Yildirim, "Asymmetric amplitude variation for four tone small signal input gan hemt at different temperatures", Journal of the Faculty of Engineering and Architecture of Gazi University, 25(4): 779-786, (2010).
• 3. Yu H.B., Lisesivdin S.B., Bolukbas B., Kelekci O., Ozturk M.K., Ozcelik S., Caliskan D., Ozturk M., Cakmak H., Demirel P. and Ozbay E., "Improvement of breakdown characteristics in AlGaN/GaN/AlxGa1-xN HEMT based on a grading AlxGa1-xN buffer layer", Physica Status Solidi a-Applications and Materials Science, 207(11): 2593-2596, (2010).
• 4. Akpinar O., Bilgili A.K., Ozturk M.K., Ozcelik S. and Ozbay E., "On the elastic properties of INGAN/GAN LED structures", Applied Physics a-Materials Science & Processing, 125(2): (2019).
• 5. Vurgaftman I. and Meyer J.R., "Band parameters for nitrogen-containing semiconductors", Journal of Applied Physics, 94(6): 3675-3696, (2003).
• 6. Ponce F.A. and Bour D.P., "NItride-based semiconductors for blue and green light-emitting devices", Nature, 386(6623): 351-359, (1997).
• 7. Nakamura S., Gan Growth Using Gan Buffer Layer, Japanese Journal of Applied Physics Part 2-Letters, 30(10a): L1705-L1707, (1997).
• 8. Xing H., Keller S., Wu Y.F., McCathy L., Smorckova I.P., Buttari D., Coffie R., Green D.S., Parish G., Heikman S., Shen L., Zhang N., Xu J.J., Keller B.P., DeBaaars S.P and Mishra U.K.,, Gallium nitride based transistors, Journal of Physics-Condensed Matter, 13(32): 7139-7157, (2001).
• 9. Ghione G., Chen K.J., Egawa T., Meneghesso G., PalaciosT. and Quay R., Special Issue on GaN Electronic Devices, Ieee Transactions on Electron Devices, 60(10): 2975-2981, (2013).
• 10. Ambacher O., Foutz B., Smart J., Shealy J.R., Weimann N.G., Chu K., Murphy M., Sierakowski A.J., Schaff W.J., Eastman L.F., Dimitrov R., Mitchell A. and Stutzmann M., Two dimensional electron gases induced by spontaneous and piezoelectric polarization in undoped and doped AlGaN/GaN heterostructures. Journal of Applied Physics, 87(1): 334-344, (2000).
• 11. Moon J.S., Micovic M., Janke P., Hashimoto P., Wong W.S., Widman R.D., McCray L., Kurdoghlian and Nguyen C., GaN/AlGaN HEMTs operating at 20GHz with continuous-wave power density > 6W/mm, Electronics Letters, 37(8): 528-530, (2001).
• 12. Zhang N.Q., Moran B., DenBaars S.P., Mishra U.K., Wang X.W. and Ma T.P., Kilovolt AlGaN/GaN HEMTs as switching devices, Physica Status Solidi a-Applied Research, 188(1): 213-217, (2001).
• 13. Shealy J.R., Kaper V., Tilak V., Prunty T., Smart J.A., Green B. and Eastman L.F., An AlGaN/GaN high-electron-mobility transistor with an AlN sub-buffer layer, Journal of Physics-Condensed Matter, 14(13): 3499-3509, (2002).
• 14. Eastman L.F., Tilak V., Kaper V., Smart J., Thompson R., Green B., Shealy J.R. and Prunty T., Progress in high-power, high frequency AlGaN/GaN HEMTs, Physica Status Solidi a-Applied Research, 194(2): 433-438, (2002).
• 15. Porowski S., Grzegory I., Kolesnikov D., Lojkowski W., Jager V., Jager W., Bogdano V., Suski T. and Krukowski S., Annealing of GaN under high pressure of nitrogen, Journal of Physics-Condensed Matter, 14(44): 11097-11110, (2002).
• 16. Zhang L.B., Yan H., Zhu G., Liu S. and Gan Z.Y., Molecular dynamics simulation of aluminum nitride deposition: temperature and N : Al ratio effects, Royal Society Open Science, 5(8), (2018).
• 17. Dridi Z., Bouhafs B. and Ruterana P., First-principles investigation of lattice constants and bowing parameters in wurtzite AlxGa1-xN, InxGa1-xN and InxAl1-xN alloys, Semiconductor Science and Technology, 18(9): 850-856, (2003).
• 18. Tokarska M., Evaluation of Measurement Uncertainty of Fabric Surface Resistance Implied by the Van der Pauw Equation, IEEE Transactions on Instrumentation and Measurement, 63(6): 1593-1599, (2014).
• 19. Van der Pauw L.J., A method of measuring specific resistivity and Hall effect of discs of arbitrary shape, Philips Technical Review, 13(1): 1-9, (1958).
• 20. Swaminathan V. and MacRander A.T., Materials Aspects of Gaas and Inp Based Structures (Prentice Hall Advanced Reference Series): Prentice Hall, (1991).