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This study investigates the electrical characteristics observed in n-channel and p-channel ferroelectric field effect transistor (FeFET) devices fabricated through a similar process flow with 10 nm of ferroelectric hafnium zirconium oxide (HZO) as the gate dielectric. The n-FeFETs demonstrate a faster complete polarization switching compared to the p-channel counterparts. Detailed and systematic investigations using TCAD simulations reveal the role of fixed charges and interface traps at the HZO-interfacial layer (HZO/IL) interface in modulating the subthreshold characteristics of the devices. A characteristic crossover point observed in the transfer characteristics of n-channel devices is attributed with the temporary switching between ferroelectric-based operation to charge-based operation, caused by the pinning effect due to the presence of different traps. This experimental study helps understand the role of charge trapping effects in switching characteristics of n- and p-channel ferroelectric FETs. [ABSTRACT FROM AUTHOR]

In this paper an in – depth analysis of SiN passivated AlGaN/GaN HEMTs on sapphire and SiC substrate for radiation hardened operation has been presented. An exhaustive study comprising of Conventional, Gate Field Plate (GFP), and Dual Field Plate (DFP) architectures have been studied through exhaustive TCAD simulations under different radiation environments. Initial analysis has been carried out by intentionally subjecting the devices to heavy ion particle strikes. The particle strikes have also been localized along different positions of the device in order to examine the behavior of the architectures due to the occurrence of Single Event Effects (SEEs) in the space environment. Comparisons demonstrate an excellent reliability of DFP HEMTs in terms of resistance to the change observed in device performance parameters post heavy ion strike. The reliability of the device architectures has also been investigated in presence of proton shower by creating a virtual environment comprising of energetic protons. Due to non – ionizing energy loss (NIEL), the protons can traverse large distances in the epi – layer stack. In this regard, Substrate dependent effects have also been investigated by coupling the AlGaN/GaN stack over SiC-4 H and Sapphire substrates to study the robustness against the heavy ion and proton flux. Significant enhancement in both the OFF – State and ON – State current has been observed on the SiC-4 H substrate, indicating a robust operation for GaN on Sapphire substrates. The radiation hardness of the device architectures has also been studied by realizing thick AlGaN barriers that further improve the device performance. Finally, the device architectures are compared from an application perspective by investigating the Class AB Power Amplifier performance. Comparisons demonstrate the suitability of DFP AlGaN/GaN HEMTs in achieving both robustness against different radiation environments and as well as exhibiting higher output power density compared to its Conventional and GFP counterparts. [ABSTRACT FROM AUTHOR]

In this article, a semi-analytical model for germanium absorber-based SOI-tunnel field-effect phototransistor at 1550 nm has been proposed. The model works efficiently for a wide range of intensities i.e. 10−2 to 102 µW/µm2 under the application of a very low gate voltage of 0.54 V. Exhaustive simulations using numerical ATLAS 2D device simulation tool with LUMNINOUS optical module have been carried out to propose the merit of tunnel field-effect transistors (TFETs) over metal oxide semiconductor field effect transistors (MOSFETs) for optical applications. The proposed TFET design provides a way to assist the ultrasensitive optical interconnects at a very low gate bias of 0.54 V with a maximum sensitivity of 1.5 × 107, responsivity of 270 mA/W, and detectivity of 3.5 × 1012 Jones at low power density of 0.01 µW/µm2. The TFET performance has further been improved by introducing a heavily doped pocket in between source and channel, which serves as a potential alternative for photodetector applications. The proposed pocket-doped TFET design offers significant improvements in device optical response with optimized sensitivity of 4.1 × 107, a responsivity of 772 mA/W, and a detectivity of 9.9 × 1012 Jones at an optical intensity of 0.01 µW/µm2, gate bias of 0.45 V, and drain voltage of 0.6 V. Transient analysis has been carried out to optimize the response time of the phototransistor for both Ge-gated conventional TFET and pocket-doped architecture and the fall time of ∼0.22 ms has been achieved. [ABSTRACT FROM AUTHOR]

This investigation examines the performance of AlGaN/GaN MISHEMTs having single-gate and dual-gate with different biasing combinations to explore the linearity in terms of gmpeak, gate voltage swing (GVS) and higher-order coefficients for intermodulation distortion for low-noise amplifiers (LNAs). In addition, the influence of distinct gate biasing configurations of DG-MISHEMT on current collapse (CC) (in response to OFF-state stress in drain) has been studied using TCAD simulations. It has been observed that drop in drain current value after the gate–drain voltages return to quiescent voltages (VGSQ, VDSQ) reduces for DG-MISHEMT (when both the gates are shorted together) to 9.1% as compared with 19.4% for SG-MISHEMT. Besides, the CC phenomena for DG-MISHEMTs (for shorted gates) exhibit a slight increase from 9% to 11.8% when workfunction increases from 4.1 eV to 5.2 eV for gate G2. Further, linearity in terms of GVS is observed to be doubled for AlGaN/GaN DG-MISHEMTs with both the gates connected together as compared with device with screen gate G2 shorted to source. Additionally, radio frequency performance has been studied in terms of cut-off frequencies fT and fmax and minimum noise-figure NFmin for AlGaN/GaN SG-MISHEMT and DG-MISHEMTs for different gate to gate distance i.e., LGG =100 and 200 nm. It is observed that NFmin is minimum for AlGaN/GaN DG-MISHEMT (with gate G1 floating and gate G2 is biased and LGG =100 nm) i.e., 1.13 dB with corresponding power gain of 18.7 dB at 50 GHz. [ABSTRACT FROM AUTHOR]