Modeling and simulation of 2DEG density and intrinsic capacitances in AlInN/GaN MOSHEMT

Abstract

In this paper, an analytical model for intrinsic capacitance is developed by estimating 2-dimensional electron gas density inside the triangular quantum well in AlInN/GaN metal oxide semiconductor high-electron mobility transistors by considering gate charge and through self-consistent solution of Poisson and Schrödinger equations. The charge separation method is applied to develop the intrinsic terminal charges and then the intrinsic capacitances accordingly. In order to validate the developed model, the results are compared with TCAD device simulation results. 1-4 It provides high 2-dimensional electron gas (2DEG) density along with high-electron mobility, which makes it very suitable for high-frequency applications. Along with the significant device development and performance improvements in III-Nitride-based devices, analytical and numerical models are highly desirable to validate the device. So in this work, capacitance modeling of AlInN/GaN MOSHEMT is emphasized for reliable and accurate device performance in mm and sub-mm wave regime. An analytical model for intrinsic capacitance in GaN HEMT has been developed by considering the parasitic components. 5 Closed form charge-based I-V and C-V characteristics are developed for GaN-based MODFETs. 6-9 The effect of structural parameters on 2DEG density and C-V characteristics is demonstrated through numerical simulations. 10Recently, Jena et al developed the gate capacitance model for MOSHEMT device structure by considering the quantum capacitance.11,12 However, to date, there is no model present in the literature explaining the intrinsic capacitances formed in AlInN MOSHEMTs. Therefore, in this paper, gate, drain. and source terminal charges are modeled and the corresponding intrinsic capacitances in AlInN/GaN MOSHEMT are obtained. Section 2 describes the device structure, simulation setup and model development. In Section 3, results are discussed. Finally, the paper is concluded in Section 4. | MODEL DEVELOPMENTThe schematic view of AlInN/GaN MOSHEMT structure used to develop the compact analytical intrinsic capacitance model is shown in Figure 1

Microwave frequency small-signal equivalent circuit parameter extraction for AlInN/GaN MOSHEMT

“…The AlN layer is used at the interface of AlInN/GaN to increase the carrier concentration and mobility. 2 At room temperature, the device exhibited 2DEG (2D electron gas) charge density of 2.3 3 10 13 cm 22 and carrier mobility of 1260 cm 2 /V-s. In this device 8 nm thick HfO 2 oxide layer is used.…”

“…The device structure consists of 2.5 μm‐thick GaN channel layer followed by 1.5 nm‐thick AlN (Aluminum Nitride) inter layer and 15‐nm AlInN barrier layer with Al content of 83%. The AlN layer is used at the interface of AlInN/GaN to increase the carrier concentration and mobility . At room temperature, the device exhibited 2DEG (2D electron gas) charge density of 2.3 × 10 13 cm − 2 and carrier mobility of 1260 cm 2 /V‐s.…”

“…III‐Nitride based AlInN/GaN MOS‐HEMT is a highly reliable emerging device which has attracted significant attention in RF, microwave and millimeter‐wave frequency applications due to suitable material properties of GaN . The unique material properties of GaN and rapid progress of GaN technology results in development of monolithic microwave integrated circuit (MMIC) of low noise amplifier (LNA), voltage controlled oscillator (VCO), mixer and so forth .…”

“…III-Nitride based AlInN/GaN MOS-HEMT is a highly reliable emerging device which has attracted significant attention in RF, microwave and millimeter-wave frequency applications due to suitable material properties of GaN. [1][2][3][4][5] The unique material properties of GaN and rapid progress of GaN technology results in development of monolithic microwave integrated circuit (MMIC) of low noise amplifier (LNA), voltage controlled oscillator (VCO), mixer and so forth. 6,7 However, with the continuous developments in GaN technology, accurate and reliable models of microwave heterostructure devices are required to develop and design active circuits in present day communication systems.…”

Modeling and simulation of DC and microwave characteristics of AlInN(AlGaN)/AlN/GaN MOSHEMTs with different gate lengths

“…The total gate to channel charge of the device can be considered as the combination of the charges present in the oxide and inversion layers. The total gate charges calculated by integrating the 2DEG channel charge density under the gate region of the device are expressed as …”