Abstract In this work, we propose a novel π-gate laterally diffused MOS (π-LDMOS) structure optimized for high-voltage (HV) applications. A comprehensive device-level investigation is carried out using a well-calibrated TCAD simulation framework. The study systematically explores the trade-offs among critical performance metrics relevant to both analog and digital domains, as well as the device's safe operating area (SOA). The proposed device exhibits a 23 % enhancement in V BR with only a 6 % increase in R ON at gate to source voltage (V GS ) of 1.8 V, when compared to the standard LDMOS. Furthermore, the proposed π-LDMOS demonstrates a 90 % improvement in f t and a 200 % increase in g m /g ds at V GS = 1.8 V. These enhancements are primarily attributed to significant reductions in gate capacitance (C gg ) and output conductance (g ds ), while maintaining a similar g m relative to the standard LDMOS (std-LDMOS). As a result, the π-LDMOS achieves 43 % and 65 % improvements in Baliga's and Johnson's figures of merit, respectively. Overall, the proposed π-LDMOS exhibits superior performance, positioning it as a strong candidate for both analog and high-voltage power applications.Index Terms-π-gate,

Abstract In complementary FET (CFET) architectures, the vertically stacked device configuration inherently limits heat dissipation paths, leading to severe self-heating effects (SHE), particularly in the upper device. This work presents an electro-thermal and reliability analysis of CFETs employing a dualsubstrate architecture, which provides an additional thermal conduction path to mitigate SHE. The proposed structure is quantitatively compared with nanosheet FETs (NS-FETs), monolithic CFETs (mCFETs), and sequential CFETs (sCFETs) under identical operating conditions using precisely calibrated 3D TCAD simulations. Electro-thermal simulation results show that, compared to the NS-FET, the dual-substrate CFET with a 30-nm top silicon layer reduces the maximum temperature rise (∆T MAX ) and thermal resistance (R TH ) from 60.3% and 76.3% in the conventional sCFET to 12.6% and 26.1%, respectively. To identify the optimal substrate thickness, a figure of merit (FoM), defined as the product of propagation delay and maximum temperature (T MAX ), is introduced. The FoM reaches a minimum at a top substrate thickness of 30 nm, indicating the optimal performancethermal trade-off. Furthermore, device reliability is quantitatively evaluated in terms of hot-carrier injection (HCI) and bias temperature instability (BTI) lifetime models, showing 4.7× and 10.5× improvements, respectively, for the proposed CFET with a 30-nm additional substrate compared to the conventional sCFET. These results demonstrate that the proposed structure effectively alleviates SHE in CFETs and provides improved long-term device reliability for advanced logic applications.

Abstract Two-dimensional electron gases (2DEGs) play a central role in a wide range of electronic components. A thorough understanding of mobility-limiting scattering mechanisms is therefore crucial for the design of high-performance devices. In particular, with continuing device miniaturization, scattering processes such as interface roughness scattering increasingly influence the mobility of more confined 2DEGs. This paper reviews the theoretical treatment of the essential scattering mechanisms within the effective mass theory, along with the solution of the Boltzmann transport equation via linearization and the momentum relaxation time approximation. The calculation of total mobility is discussed, and recent theoretical predictions of mobility enhancement in AlN/GaN high electron mobility transistors (HEMTs) are highlighted.

Abstract Intensity-modulated proton therapy (IMPT) employs proton radiation rather than conventional x-rays to treat cancerous tumors. This approach offers significant advantages by minimizing the radiation exposure of surrounding healthy tissue, leading to improved patient outcomes and reduced side effects compared to traditional x-ray therapy. To ensure patient safety, each treatment plan must be experimentally validated before clinical implementation. However, current dosimetry devices face limitations in performing angled beam measurements and obtaining multi-depth assessments, both of which are essential for verifying IMPT treatment plans. In this study, the performance of a β -Ga 2 O 3 -based metal–semiconductor–metal detector with a low-noise amplifier has been studied and evaluated under various proton radiation doses and energy levels delivered by a MEVION S250i proton accelerator. The detector’s performance was also compared with that of an ionization chamber. The β -Ga 2 O 3 detector exhibited a linear response with proton dose for single-spot irradiations, and its response to varying proton energies closely matched both the ion chamber data and simulated dose distributions. These findings highlight the potential of β -Ga 2 O 3 -based detectors as robust dosimetry devices for IMPT applications.

Abstract This document addresses the regulation of leakage current induced by composition-correlated bandgap depletion for novel bandgap gradient multilayer heterojunction (BGMH) Hg1-xCdxTe long-wavelength infrared (LWIR) photodiodes. The issue that the energy band barrier impedes the hole diffusion process is successfully eliminated by controlling the relative position of the electric field and the heterojunction material. Here, the TCAD-based device model is employed to verify the energy band distribution, and several means, including pre-etching before doping and reducing absorber-layer concentration, are proposed to optimize the device performance. Consequently, the “turn-on” bias (|Vto|) required for the device to transition into a diffusion-dominated is reduced from 1.2 V to less than 0.2 V. Finally, an 11.5 µm LWIR BGMH device is utilized to confirm the proposed model and enhanced quantum efficiency from 33.2% to 70.0%, which can effectively support engineering applications.