Enhancement Performance of High Electron Mobility Transistor (HEMT) Based on Dimensions Downscaling

This paper aims to enhance the performance of the High Electron Mobility Transistor (HEMT) according to downscaling dimensions based on the electrical properties and semiconductor materials (GaN, Si3N4, ALGaN and Si). This is to solve difficulties with reducing dimensions and ensuring HEMT has the highest performance possible. This goal was met when the physical scaling restrictions of channel diameters for different HEMTs were concurrently shrunk without compromising their performance. A simula-tion study was done using four variable factors (length, width, of the channel and length, width of the source and drain). Three electrical characteristics were used to assess the impact of altering dimensions on the performance of each kind of HEMT: threshold voltage Vt, ON-state/OFF-state current (ION/IOFF) ratio, and transconductance gm. To conduct experimental simulations under the specified situation, the well-known Silvaco TCAD simulation tool was used. The acquired simulation results revealed that the optimum performance for the downscaling device was achieved at the channel length of 1.6μm, the channel width of 0.3μm, the length of source and drain is 0.4μm and finally the width of source and drain is 0.05 μm

Transfer-free growth of graphene on SiO2 insulator substrate from sputtered carbon and nickel films

AbstractHere we demonstrate the growth of transfer-free graphene on SiO2 insulator substrates from sputtered carbon and metal layers with rapid thermal processing in the same evacuation. It was found that graphene always grows atop the stack and in close contact with the Ni. Raman spectra typical of high quality exfoliated monolayer graphene were obtained for samples under optimised conditions with monolayer surface coverage of up to 40% and overall graphene surface coverage of over 90%. Transfer-free graphene is produced on SiO2 substrates with the removal of Ni in acid when Ni thickness is below 100nm, which effectively eliminates the need to transfer graphene from metal to insulator substrates and paves the way to mass production of graphene directly on insulator substrates. The characteristics of Raman spectrum depend on the size of Ni grains, which in turn depend on the thickness of Ni, layer deposition sequence of the stack and RTP temperature. The mechanism of the transfer-free growth process was studied by AFM in combination with Raman. A model is proposed to depict the graphene growth process. Results also suggest a monolayer self-limiting growth for graphene on individual Ni grains

Preparation and Study of the Physical Properties of CdSe Films Deposited by a Chemical Bath Method and Exposed to Neutron Irradiation: Effect of neutron irradiation on a CdSe film prepared

This study deals with the preparation of CdSe films using two sources of cadmium, (CdCl2) and (CdSO4), and studying the effect of neutron irradiation on their optical and structural properties. Using CBD method, the films were prepared on glass substrates at a temperature of 50 •C, with a deposition time of 3 hours. These films were exposed to the neutron beam from the radioactive source (Am241-Be10) with a neutron flux (3*105 n/cm2.s) and an energy of 5 MeV for 7 days. It was noted that neutron irradiation has a significant effect on the physical properties of the films. Using a UV-V spectrophotometer, the optical properties of the films were studied. It was found that the absorption coefficient (?) and the energy gap increase with irradiation, and from the following XRD, FESEM and EDX measurements, the shape and structure of the prepared and irradiated films were determined. X-ray measurements have shown that there are preferred directions for grain growth [111], [220], and [311]. It was also observed that the grain size increases, while the relative density decreases with irradiation. As for FESEM measurement, it was noted that the surface shape of the films is greatly affected when exposed to neutron radiation

Enhancement Performance of High Electron Mobility Transistor (HEMT) Based on Dimensions Downscaling

This paper aims to enhance the performance of the High Electron Mobility Transistor (HEMT) according to downscaling dimensions based on the electrical properties and semiconductor materials (GaN, Si3N4, ALGaN and Si). This is to solve difficulties with reducing dimensions and ensuring HEMT has the highest performance possible. This goal was met when the physical scaling restrictions of channel diameters for different HEMTs were concurrently shrunk without compromising their performance. A simula-tion study was done using four variable factors (length, width, of the channel and length, width of the source and drain). Three electrical characteristics were used to assess the impact of altering dimensions on the performance of each kind of HEMT: threshold voltage Vt, ON-state/OFF-state current (ION/IOFF) ratio, and transconductance gm. To conduct experimental simulations under the specified situation, the well-known Silvaco TCAD simulation tool was used. The acquired simulation results revealed that the optimum performance for the downscaling device was achieved at the channel length of 1.6μm, the channel width of 0.3μm, the length of source and drain is 0.4μm and finally the width of source and drain is 0.05 μm