Page 8 - PEN eBook March 2022
P. 8
DESIGN
Drain-Current
Characteristics of
Enhancement-Mode GaN
HEMTs
By Maurizio Di Paolo Emilio, editor-in-chief of Power Electronics News
Two distinct structures have been developed for the enhancement mode of GaN-based
high-electron–mobility transistors (HEMTs). These two modes are the metal-insulator–
semiconductor (MIS) structure, which has a low gate leakage current driven by voltage, and
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the gate-injection transistor (GIT), which has a ridge structure and a high threshold voltage.
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Both have some shortcomings as well. MIS has less reliability for gate interference and a low
threshold voltage, whereas GIT has less gate switching speed and a higher gate leakage current.
The original article is available here.
Figure 1 shows the setup used to test these two structures. A single model can be used for both MIS
and GIT structures. GIT is used for developing equivalent circuits using current models, whereas
MIS is used for core drain-current modeling. Following that, S-parameter measurements are used
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to evaluate circuits for each of these devices.
14 MARCH 2022 | www.powerelectronicsnews.com
