A systematic modulation of the carrier type in molybdenum ditelluride (MoTe2) field‐effect transistors (FETs) is described, through rapid thermal annealing (RTA) under a controlled O2 environment ...(p‐type modulation) and benzyl viologen (BV) doping (n‐type modulation). Al2O3 capping is then introduced to improve the carrier mobilities and device stability. MoTe2 is found to be ultrasensitive to O2 at elevated temperatures (250 °C). Charge carriers of MoTe2 flakes annealed via RTA at various vacuum levels are tuned between predominantly pristine n‐type ambipolar, symmetric ambipolar, unipolar p‐type, and degenerate‐like p‐type. Changes in the MoTe2‐transistor performance are confirmed to originate from the physical and chemical absorption and dissociation of O2, especially at tellurium vacancy sites. The electron branch is modulated by varying the BV dopant concentrations and annealing conditions. Unipolar n‐type MoTe2 FETs with a high on–off ratio exceeding 106 are achieved under optimized doping conditions. By introducing Al2O3 capping, carrier field effect mobilities (41 for holes and 80 cm2 V−1 s−1 for electrons) and device stability are improved due to the reduced trap densities and isolation from ambient air. Lateral MoTe2 p–n diodes with an ideality factor of 1.2 are fabricated using the p‐ and n‐type doping technique to test the superb potential of the doping method in functional electronic device applications.
Unipolar p‐ and n‐type molybdenum ditelluride (MoTe2) field‐effect transistors are achieved through controllable doping techniques. With Al2O3 capping, hole and electron mobility are improved to 41 and 80 cm2 V−1s−1, respectively. Lateral MoTe2 p–n diodes with an ideality factor of 1.2 are fabricated by combining the p‐ and n‐type doping techniques.
The fabrication of a polymeric Ohmic contact interlayer between a metal and a 2D material using solution‐processed benzyl viologen (BV) is reported here. Predoping of the polymer alters the contact ...surface to obtain electron‐doped materials with ultrahigh work functions that significantly enhance the current density across the contact and reduce the contact resistance and Schottky barrier height. The fabrication of solution‐processed polymeric contacts for the preparation of high mobility MoS2, WSe2, MoTe2, and BP (black phosphorous) FETs with significantly lowered contact resistance is demonstrated. Ohmic contacts are achieved and produce 3‐, 700‐, 3000‐, and 17‐fold increases in electron mobilities, respectively, when the bottom gate voltage is 10 V compared to those respective materials alone. Ambipolar and p‐type 2D material based FETs could, therefore, be transformed into n‐type FETs. Most importantly, the devices exhibit excellent stability in both ambient and vacuum.
Solution‐processed polymeric contacts used in 2D semiconductor devices are reported here. Predoping of the benzyl viologen alters the contact surface to obtain electron‐doped materials with high work functions. Ohmic contacts are induced by the polymer and the thus formed devices produce 3‐, 700‐, 3000‐, and 17‐fold increases in the mobilities for MoS2, WSe2, MoTe2, and black phosphorus devices, respectively.
This exciting new resource describes a unified approach to non-linear analysis and design involving compound semiconductor field effect transistors FETs and heterojunction field effect transistors ...HFETs. It provides an understanding of the characterization and analysis devices made by non-linear design, highlighting the relationship between design and performance. The rarely acknowledged errors inherent in extracting capacitive and conductance elements, as required by all circuit models, from measurements made at the terminals of a device is given, and how these limitations and restrictions often yield workable results is
Silicon RF power MOSFETS Baliga, B. Jayant; Baliga, B. Jayant
2005., 2005, 2005-03-01, c2005
eBook
The world-wide proliferation of cellular networks has revolutionized telecommunication systems. The transition from Analog to Digital RF technology enabled substantial increase in voice traffic using ...available spectrum, and subsequently the delivery of digitally based text messaging, graphics and even streaming video. The deployment of digital networks has required migration to multi-carrier RF power amplifiers with stringent demands on linearity and efficiency. This book describes the physics, design considerations and RF performance of silicon power Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) that are at the heart of the power amplifiers. The recent invention and commercialization of RF power MOSFETs based on the super-linear mode of operation is described in this book for the first time. In addition to the analytical treatment of the physics, extensive description of transistor operation is provided by using the results of numerical simulations. Many novel power MOSFET structures are analyzed and their performance is compared with those of the laterally-diffused (LD) MOSFET that are currently used in 2G and 3G networks.
Thin Film Metal-Oxides provides a representative account of the fundamental structure-property relations in oxide thin films. Functional properties of thin film oxides are discussed in the context of ...applications in emerging electronics and renewable energy technologies. Readers will find a detailed description of deposition and characterization of metal oxide thin films, theoretical treatment of select properties and their functional performance in solid state devices, from leading researchers. Scientists and engineers involved with oxide semiconductors, electronic materials and alternative energy will find Thin Film Metal-Oxides a useful reference.
Provides the reader with a deep understanding of modeling and design strategies of Current-Mode digital circuits Organizes in a coherent manner all the original and powerful authors' results in the ...domain of Current-Mode digital circuits.
This is the first book dedicated to the next generation of MOSFET models. Addressed to circuit designers with an in-depth treatment that appeals to device specialists, the book presents a fresh view ...of compact modeling, having completely abandoned the regional modeling approach. Both an overview of the basic physics theory required to build compact MOSFET models and a unified treatment of inversion-charge and surface-potential models are provided. The needs of digital, analog and RF designers as regards the availability of simple equations for circuit designs are taken into account. Compact expressions for hand analysis or for automatic synthesis, valid in all operating regions, are presented throughout the book. All the main expressions for computer simulation used in the new generation compact models are derived.
