Abstract
Gallium nitride (GaN) and aluminum gallium nitride (AlGaN) heterostructures are used in high electron mobility transistors (HEMTs) due to their performance in high-frequency and high-power applications. However, dislocation density in GaN significantly impacts electron mobility and overall device efficiency. In this study, the relationship between dislocation density and electron mobility was investigated using two samples of GaN with thicknesses of 2 µm and 11 µm grown by metal-organic chemical vapor deposition (MOCVD), and HEMTs produced using these samples. Data concerning dislocation density was collected and analyzed using atomic force microscopy and X-ray diffraction, while electrical properties were evaluated through capacitance-voltage, Van der Pauw, and Hall measurements on corresponding HEMT structures. Analysis showed a reduction in dislocation density from cm-2 to cm-2, a 63.85% decrease, with increased GaN thickness. This reduction correlated with an increase in electron mobility from 547.6 cm2/V.s to 1719.8 cm2/V.s, a 214% increase. The results confirm that lowering dislocation density enhances carrier mobility which improves device performance. This work highlights the importance of having high quality semiconductor material in HEMTs and methods to produce this high-quality material.
Recommended Citation
Colglazier, Kelsey M.
(2026)
"Effect of Dislocation Density on the Carrier Mobility of GaN/AlGaN HEMT,"
Caroliniana Undergraduate Research Journal: Vol. 1:
Iss.
2, Article 6.
Available at:
https://scholarcommons.sc.edu/usc-curj/vol1/iss2/6