GaN HEMT with AlGaN back barrier for high power MMIC switch application

Abstract

0.25 m GaN HEMT with AlGaN back barrier for high power switch application has been presented. By introducing AlGaN back barrier, the buffer layer breakdown voltage for the metal-organic chemical vapor deposited AlGaN/GaN hetero-structure on 3-inch SiC substrate showed a considerable increment, which was nearly 4 and 2 of that for the conventional GaN buffer layer and GaN buffer layer with Fe doped, respectively. GaN switch HEMTs with source to drain spacing of 2, 2.5, 3, 3.5 and 4 m were fabricated on the AlGaN/GaN epitaxial material with AlGaN back barrier and estimated off state power handling for the GaN switch HEMTs were 25.0, 46.2, 64.0, 79.2, and 88.4 W, respectively. A demonstrator DC-12 GHz GaN SPDT MMIC switch was designed in reflective series-shunt-shunt configuration based on the GaN HEMT, with a source to drain spacing of 2.5 m. The developed SPDT MMIC switch showed a maximum insertion loss of 1.0 dB and a minimum isolation of 30 dB at a frequency range of DC-12 GHz. A power handling capability of 44.1 dBm was achieved at 10 GHz for the MMIC switch with continuous wave power compression measurement.

Simulation modelling of III‐Nitride / β ‐Ga 2 O 3 Nano‐HEMT for microwave and millimetre wave applications

“…41 It is observed from Figure 4 that the proposed HEMT with field-plate gets breakdown at 108 V whereas without field-plate it gets breakdown at 42 V. The AlGaN back barrier underlying GaN is mostly responsible for enhancement in breakdown voltage that boosts CB level near GaN buffer layer. [42][43][44] Figure 5 illustrates the recommended HEMT's breakdown properties on various substrates with a fieldplate having a 30 nm gate recessed depth.…”

Small-signal modeling of GaN HEMT switch with a new intrinsic elements extraction method

“…The gate of the GaN HEMT switch device is connected to the ground by a blocking resistor (r g = 4 kΩ), which is used to decouple the circuit from the common gate ground. [22][23][24] In order to solve the problem in the traditional extraction method, the blocking resistor is taken into consideration during extracting the intrinsic elements, which is the first time parasitic elements have been used in the intrinsic elements extraction process. By using this new method, the Y parameters of the intrinsic part can be expressed as…”

Self‐consistent simulation of two‐dimensional electron gas characteristics of a novel (InxAl1–xN/AlN) MQWs/InN/GaN heterostructure

“…Recently, in order to improve the carrier density, many GaN‐based heterostructures using Al x Ga 1– x N/AlN SLs as a barrier have been investigated . Meanwhile, a p‐type buffer layer, a AlGaN buffer layer, and a InGaN buffer layer have been used to improve channel confinement of 2DEG . The (In x Al 1– x N/AlN) MQWs/InN/GaN heterostructure has both a larger 2DEG sheet density and better confinement of 2DEG than conventional InAlN/GaN and AlGaN/GaN heterojunctions.…”