Publication Date:
2015-10-20
Description:
The parameters of open-gate structures treated with different etching time were monitored during the gate recess process, and their impacts on the threshold voltage ( V th ) of final fabricated AlGaN/GaN high electron mobility transistors (HEMTs) based on open-gate structures were discussed in this paper. It is found that V th can exceed 0 V when channel resistance in the recessed region ( R on-open ) increases over ∼275 Ω mm, maximum current ( I Dmax ) decreases below ∼29 mA/mm, or recessed barrier thickness ( t RB ) is below ∼7.5 nm. In addition, t RB obtained by atomic force microscopy measurements and C-V measurements are also compared. Finally, theoretical common criteria based on the experimental results of this work for t RB and R on-open were established to evaluate the V th of a regular normally-off AlGaN/GaN HEMTs. The results indicate that these parameters of open-gate structure can be utilized to achieve normally-off HEMTs with controllable V th .
Print ISSN:
0003-6951
Electronic ISSN:
1077-3118
Topics:
Physics
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