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

Öz

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.

Anahtar Kelimeler

• HEMT,XRD,Hall,strain,stress

Proje Numarası

2016K121220

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

Öz

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.

Anahtar Kelimeler

• HEMT,XRD,Strain,Stress

Destekleyen Kurum

Presidency Strategy and Budget Directorate

Proje Numarası

2016K121220

Teşekkür

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

Kaynakça

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