Two-dimensional (2D) magnetic materials have attracted significant attention owing to their tunable magnetic properties and prospective applications in next-generation spintronic devices. However, their practical utilization is often limited by poor air stability. 2D magnetic metal oxides, which generally exhibit better stability under ambient conditions, represent a promising alternative. In this work, high-quality CoO nanosheets were successfully synthesized via chemical vapor deposition. Structural characterization confirms a well-defined triangular morphology and single-crystalline nature, with the thinnest nanosheets reaching approximately 10.1 nm in thickness. Magnetic measurements reveal significant magnetic anisotropy with an in-plane easy magnetization axis and a transition temperature of approximately 159 K. Our study provides a feasible approach for the controllable synthesis of air-stable 2D magnetic semiconductors, thereby laying a foundation for their potential application in low-power spintronic devices.

The computational cost of TCAD simulations is becoming prohibitively high with the complexity of advanced process technologies, making simulation acceleration a critical research priority. While end-to-end surrogate models mapping process recipes to device structures and characteristics offer a promising alternative, their application is often limited by poor generalizability and explainability. In this work, we present MPNet, a modular deep learning surrogate modeling framework for process TCAD. MPNet comprises distinct surrogate models for individual process modules, which are assembled into an integrated framework. These modular models employ a novel UNet-attention feature evolution method to capture the complex evolutions of device geometry and doping profiles. Each module can be trained separately on its individual process, after which the modules are cascaded and jointly fine-tuned to minimize error accumulation throughout the cascade. The efficacy of the proposed MPNet framework is demonstrated through a MOSFET integrated process TCAD case study. Results show that MPNet achieves a computational speedup of over 103 times compared to conventional TCAD, while maintaining predictive fidelity exceeding 98%. Finally, to illustrated the application of the proposed framework, MPNet is coupled with a PSO algorithm, showcasing its utility for fast process optimization to meet specific process targets.

Al-rich Al_xGa_1−xN (x ≥ 0.8) is promising for power and deep-ultraviolet (DUV) optoelectronic applications, owing to its ultra-wide bandgap and excellent thermal stability. However, forming low-resistivity contacts on n-type Al-rich AlGaN remains a significant challenge. In this work, we utilized an Au-free Ti/Al/Ti metal stack contact on n-type Al-rich AlGaN without graded layers. Record-low contact resistivities were achieved after annealing: 1.52×10⁻⁶ Ω·cm² for n-Al_0.8Ga_0.2N, 3.56×10⁻⁶ Ω·cm² for n-Al_0.86Ga_0.14N, and 5.79×10⁻⁵ Ω·cm² for n-Al_0.9Ga_0.1N. These results demonstrate a significant advancement in forming low-resistance contacts directly on Al-rich n-AlGaN, offering a viable path forward for next-generation power electronics and DUV optoelectronic devices.

This work demonstrates a high-performance vertical GaN p-i-n diode based on a buried p-layer n-p-i-n epitaxial structure. The post-etch magnesium (Mg) diffusion process is applied to suppress the etch-induced surface damage on the p-GaN layer. The Mg diffusion effectively reduces the valence band barrier from 2 eV to 1.1 eV, yielding a low specific contact resistivity of 6.521 × 10⁻⁴ Ω·cm². As a result, the fabricated devices exhibit markedly enhanced forward characteristics, including a reduced turn-on voltage of 3.3 V and a specific on-resistance of 0.92 mΩ·cm2. Temperature-dependent forward I-V measurements indicate that the dominant carrier transport mechanism evolves from defect-related tunneling in the etched devices toward transport dominated by intrinsic p–n junction conduction after Mg diffusion. In addition, the devices exhibit excellent stability in forward conduction, with a voltage variation of approximately 0.028 V. These results indicate that Mg diffusion effectively improves the contact characteristics degraded by ICP etching and provide a viable approach for achieving high-performance and reliable vertical GaN power devices.

In this paper, a compact and low-power sub-THz direct-conversion receiver with a second-harmonic-remixed LO chain is proposed. Based on a common-mode second-harmonic-enhanced network, the common-mode second-harmonic voltage at the drains of the common-source differential pair in the tripler is enhanced and mixed with the fundamental voltage at the gate to generate additional differential third-harmonic voltage. Hence, the saturation output power and efficiency of the triplers used in the LO chain have been significantly improved. The power consumption of the LO chain employed in the receiver is as low as 65 mW. Measurement results demonstrate that the receiver achieves a conversion gain of 30.5 dB and a 3-dB RF bandwidth of 34 GHz, while the in-band minimum noise figure is 9.9 dB.