Improvement of transconductance and cut-off frequency in In0.1Ga0.9N back-barrier-based double-channel Al0.3Ga0.7N / GaN high electron mobility transistor by enhancing the drain source contact length ratio
Abstract
An aluminium gallium nitride / gallium nitride (Al0.3Ga0.7N/GaN ) high electron mobility transistor (HEMT) is designed at a gate length (LG) of 0.1 μ m , drain-to-source spacing (LSD) of 3 μ m and drain length to source length ratio (LD:LS) of 1. The HEMT is investigated by considering four different heterostructures, namely single channel, single channel with back-barrier, double channel and double channel with back-barrier. A two-dimensional electron gas (2DEG) is formed at the interface of AlGaN / GaN HEMT (DC HEMT). The physical importance of indium gallium nitride (InGaN) as back-barrier is to increase carrier confinement by raising the conduction band of GaN buffer. The double-channel HEMT (DC HEMT) with back-barrier shows the highest current drive. There is an improvement of 3.16% in drain current and an improvement of 4.58% in cut-off frequency at a gate-to-source voltage of -0.5 V for the DC HEMT with back-barrier compared to the DC HEMT without back-barrier. For further improvement in transconductance and cut-off frequency, the structure of DC HEMT with back-barrier is modified by increasing the drain contact length and decreasing the source contact length, that is LD:LS=3 , keeping the drain-to-source spacing unchanged, i.e. LSD=3 μ m . There is 32.55% improvement in transconductance and 14.03% improvement in cut-off frequency at a gate-to-source voltage of -0.5 V for the DC HEMT with back-barrier at LD:LS=3 compared to the DC HEMT with back-barrier at LD:LS=1.
- Publication:
-
Pramana
- Pub Date:
- December 2019
- DOI:
- 10.1007/s12043-019-1866-4
- Bibcode:
- 2019Prama..94....5M
- Keywords:
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- High electron mobility transistor;
- back-barrier;
- two-dimensional electron gas;
- heterostructures