| Autor: |
Yasuhiro Isobe, Hung Hung, Kohei Oasa, Tasuku Ono, Takashi Onizawa, Akira Yoshioka, Yoshiharu Takada, Yasunobu Saito, Naoharu Sugiyama, Kunio Tsuda, Toru Sugiyama, Ichiro Mizushima |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 2017, Vol. 121 Issue 23, p1-6, 6p |
| Abstrakt: |
Defect analysis of GaN films in high electron mobility transistor (HEMT) structures by crosssectional cathodoluminescence (X-CL) is demonstrated as a useful technique for improving the current collapse of GaN-HEMT devices, and the relationship between crystal quality and device characteristics is also investigated. The crystal quality of intrinsic-GaN (i-GaN) and carbon-doped GaN produced clearly different peak intensities of blue luminescence (BL), yellow luminescence (YL), and band-edge emission (BE), which is independently detected by X-CL. Current collapse in GaN-HEMT devices is found to be determined by the BL/BE and YL/BE ratios at the top of the i-GaN layer, which is close to the channel. Moreover, the i-GaN thickness required in order to minimize the BL/BE and YL/BE ratios and the thickness dependency of GaN for minimizing the BL/BE and YL/BE ratios depending on the growth conditions can be evaluated by X-CL. However, there is no correlation between current collapse in GaN-HEMT devices and the YL/BE ratio by conventional photoluminescence because HEMT devices consist of multiple GaN layers and the YL signal is detected from the carbon-doped GaN layer. Thus, the X-CL analysis method is a useful technique for device design in order to suppress current collapse. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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