Using synchrotron nano-beam X-ray to probe the crystal structure and its optical properties for HEMT heterostructure

• Main Authors: Liu, Tzu-Ting, 劉子霆
• Other Authors: Chou, Wu-Ching
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/scnw7c

碩士 === 國立交通大學 === 工學院加速器光源科技與應用學位學程 === 107 === High electron mobility transistor heterostructures (HEMT) reduce high defect density caused by lattice mismatch and thermal stress which increase the breakdown voltage and reduce the occurrence of vertical leakage by crystal growth techniques such as AlN nucleation layer, AlGaN buffer layer, superlattice and SiNx interlayer to improve the reliability of high electron mobility transistors in component operation. In this study, the microstructure of high electron mobility transistors is analyzed by the synchrotron focused nano-beam X-ray technology. The facility provides high flux and focused poly-chromatic X-ray at 100 nm x 100 nm for a two-dimensional spatial distribution with a sub-micron scanning platform. The diffraction faces in the Laue diffraction are used to calculate the dislocation density distribution of each crystal faces by fitting the stress distribution in the heterostructure and analyzing the stress changes in the structure to observe the effect of the buffer layer and the interlayer on the dislocation density. The optical properties of the layers in the heterostructure are analyzed in conjunction with X-ray excited optical luminescence spectroscopy.