Abstract
A physics-based analytical model for GaN high-electron-mobility transistors (HEMTs) with non-recessed- and recessed-gate structure is presented. Based on this model, the two-dimensional electron gas density (2DEG) and thereby the on-state resistance and breakdown voltage can be controlled by varying the barrier layer thickness and Al mole fraction in non-recessed depletion-mode GaN HEMTs. The analytical model indicates that the 2DEG charge density in the channel increases from 2.4 × 1012 cm−2 to 1.8 × 1013 cm−2 when increasing the Al mole fraction from x = 0.1 to 0.4 for an experimental non-recessed-gate GaN HEMT. In the recessed-gate GaN HEMT, in addition to these parameters, the recess height can also control the 2DEG to achieve high-performance power electronic devices. The model also calculates the critical recess height for which a normally-ON GaN switch becomes normally-OFF. This model shows good agreement with reported experimental results and promises to become a useful tool for advanced design of GaN HEMTS.
Highlights
GaN high-electron-mobility transistors (HEMTs) have shown great potential for use in high-power and high-frequency applications due to their wide bandgap and high electron mobility.[1,2] The defining feature of this device technology is the presence of a high-density two-dimensional electron gas (2DEG) at the AlGaN–GaN interfaceSeveral techniques have been used to design E-mode GaN devices, all of which incorporate technologies that empty the 2DEG channel underneath the gate at zero gate bias
A physics-based analytical model for the non-recessed gate GaN HEMT is presented to calculate the 2DEG charge concentration depending on the AlGaN barrier thickness
An analytical model is provided for the 2DEG charge density of the GaN HEMTs with both structures
Summary
GaN high-electron-mobility transistors (HEMTs) have shown great potential for use in high-power and high-frequency applications due to their wide bandgap and high electron mobility.[1,2] The defining feature of this device technology is the presence of a high-density two-dimensional electron gas (2DEG) at the AlGaN–GaN interfaceSeveral techniques have been used to design E-mode GaN devices, all of which incorporate technologies that empty the 2DEG channel underneath the gate at zero gate bias. Understanding the physical mechanisms behind the formation of the 2DEG is crucial to model the 2DEG charge density under the gate and to device design.[11] Experimental research has shown that the presence of donor states at the AlGaN surface is the main source of the electrons in the 2DEG.[12,13] For non-recessed-gate GaN HEMT structures, Gordon et al.[14] showed that the 2DEG density varies with the barrier layer thickness.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
