Researchers from Arizona State University, led by Nabasindhu Das and Hari Nair, have made significant strides in the development of high-performance semiconductor devices using Beta-Gallium Oxide (Beta-Ga2O3). Their work, published in the IEEE Electron Device Letters, focuses on enhancing the performance of FinFETs, a type of transistor used in advanced electronic circuits.
The team designed and demonstrated high-performance Beta-Ga2O3 FinFETs utilizing MOCVD-grown Silicon (Si) delta-doped channels. Delta-doping is a technique where a very thin layer of dopant atoms is introduced into the channel region of the transistor to enhance carrier transport and electrostatic control. The researchers achieved a record high sheet charge density of 3.3×10^13 cm^-2 using 100 nm fin channels. This high charge density resulted in a peak drain current of 410 mA/mm and a peak transconductance of 60 mS/mm, indicating excellent device performance.
The FinFET architecture, which uses a three-dimensional structure to control the channel more effectively, enabled strong gate modulation. This resulted in a high Ion/Ioff ratio between 10^8 and 10^9, meaning the device can switch between on and off states very effectively. Additionally, the researchers achieved a low contact resistance of 0.42 ohm.mm to the Si delta-doped channel using MOCVD contact regrowth, which is crucial for minimizing power loss in the device.
Small-signal RF characterization revealed a current-gain cutoff frequency (fT) of 3.8 GHz and a maximum oscillation frequency (fMAX) of 2.1 GHz for a 0.8-micrometer gate length. These frequencies are indicative of the device’s potential for high-frequency applications.
The practical applications of this research for the energy sector are significant. High-performance Beta-Ga2O3 FinFETs can be used in power electronics, which are essential for converting and controlling electrical energy in various applications. These devices can operate at high voltages and frequencies, making them suitable for renewable energy systems, electric vehicles, and smart grids. The enhanced performance and efficiency of these transistors can lead to more compact and reliable power conversion systems, reducing energy losses and improving overall system performance.
In summary, the research demonstrates the efficacy of combining precision delta-doping with a 3D FinFET geometry for high-frequency Beta-Ga2O3 electronics. This work establishes a platform for future RF and high-power applications, paving the way for advancements in the energy sector. The research was published in the IEEE Electron Device Letters, a reputable journal in the field of semiconductor devices.
This article is based on research available at arXiv.