Several μ-bridge structures for InP-based heterojunction bipolar transistors （HBTs） are reported. The radio frequency measurement results of these InP HBTs are compared with each other. The comparison shows that μ...
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Several μ-bridge structures for InP-based heterojunction bipolar transistors （HBTs） are reported. The radio frequency measurement results of these InP HBTs are compared with each other. The comparison shows that μ-bridge structures reduce the parasites and double p-bridge structures have a better effect. Due to the utilization of the double/^-bridges, both the cutoff frequency fτ and also the maximum oscillation frequency fτ of the 2 × 12.5 μm2 InP/InGaAs HBT reach nearly 160 GHz. The results also show that the μ-bridge has a better effect in increasing the high frequency performance of a narrow emitter InP HBT.
Silicon nanocrystals synthesized by electron beam (e-beam) evaporation of Si and SiO2 mixture are studied. Rutherford backscattering spectrometry of the as-deposited Si-rich silicon dioxide or oxide (SRO) thin film sh...
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Silicon nanocrystals synthesized by electron beam (e-beam) evaporation of Si and SiO2 mixture are studied. Rutherford backscattering spectrometry of the as-deposited Si-rich silicon dioxide or oxide (SRO) thin film shows that after evaporation, the Si and SiO2 concentration is well kept, indicating that the e-beam evaporation is suitable for evaporating mixtures of Si and SiO2. The SRO thin films are annealed at different temperatures for two hours to synthesize silicon nanocrystals. For the sample annealed at 1050℃, silicon nanocrystals with different sizes and the mean diameter of 4.5 nm are evidently observed by high resolution transmission electron microscopy (HRTEM). Then the Raman scattering and photoluminescence spectra arising from silicon nanocrystals are further confirmed the above results.
A new architecture of digital processors for passive UHF radio-frequency identification tags is proposed. This architecture is based on ISO/IEC 18000-6C and targeted at ultra-low power consumption. By applying methods...
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A new architecture of digital processors for passive UHF radio-frequency identification tags is proposed. This architecture is based on ISO/IEC 18000-6C and targeted at ultra-low power consumption. By applying methods like system-level power management, global clock gating and low voltage implementation, the total power of the design is reduced to a few microwatts. In addition, an innovative way for the design of a true RNG is presented, which contributes to both low power and secure data transaction. The digital processor is verified by an integrated FPGA platform and implemented by the Synopsys design kit for ASIC flows. The design fits different CMOS technologies and has been taped out using the 2P4M 0.35 μm process of Chartered Semiconductor.
In this paper, we demonstrate a Monte Carlo simulator for ambipolar Schottky barrier MOSFETs which includes tunneling and thermal emission of electrons and holes and the appropriate treatment of carrier transport at n...
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Design of a CMOS readout circuit for 160x120 format microcantilever infrared FPAs with snapshot integration is presented in this paper. The pixel pitch is 50m and capacitive trans-impedance amplifier is used in pixel ...
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Double gate SBFET with asymmetric barrier heights at source/drain and the symmetric DG-SBFET are simulated. A comparative study between them is made. We have found that the DG-ASBFET is more appropriate for LOP and LS...
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A readout integrated circuit (ROIC) for uncooled microcantilever infrared focal plane arrays (IRFPAs) based on capacitive readout is proposed. The ROIC is optimized according to noise modeling and analysis to reduce n...
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Electron transport properties in AlGaN/GaN heterostructures with different Al-contents have been in-vestigated from room temperature up to 680 K. The temperature dependencies of electron mobility have been systematica...
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Electron transport properties in AlGaN/GaN heterostructures with different Al-contents have been in-vestigated from room temperature up to 680 K. The temperature dependencies of electron mobility have been systematically measured for the samples. The electron mobility at 680 K were measured as 154 and 182 cm2/V.s for Al0.15Ga0.85N/GaN and Al0.40Ga0.60N/GaN heterostructures,respectively. It was found that the electron mobility of low Al-content Al0.15Ga0.85N/GaN heterostructure was less than that of high Al-content Al0.40Ga0.60N/GaN heterostructure at high temperature of 680 K,which is different from that at room temperature. Detailed analysis showed that electron occupations in the first subband were 75% and 82% at 700 K for Al0.15Ga0.85N/GaN and Al0.40Ga0.60N/GaN heterostructures,respectively,and the two dimensional gas (2DEG) ratios in the whole electron system were 30% and near 60%,respectively. That indicated the 2DEG was better confined in the well,and was still dominant in the whole electron system for higher Al-content AlGaN/GaN heterostructure at 700 K,while lower one was not. Thus it had a higher electron mobility. So a higher Al-content AlGaN/GaN heterostructure is more suitable for high-temperature applications.
Using depletion approximation theory and introducing acceptor defects which can characterize radiation induced deep-level defects in AlGaN/GaN heterostructures,we set up a radiation damage model of AlGaN/GaN high elec...
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Using depletion approximation theory and introducing acceptor defects which can characterize radiation induced deep-level defects in AlGaN/GaN heterostructures,we set up a radiation damage model of AlGaN/GaN high electron mobility transistor （HEMT） to separately simulate the effects of several main radiation damage mechanisms and the complete radiation damage effect simultaneously considering the degradation in mobility. Our calculated results,consistent with the experimental results,indicate that thin AlGaN barrier layer,high Al content and high doping concentration are favourable for restraining the shifts of threshold voltage in the AlGaN/GaN HEMT;when the acceptor concentration induced is less than 10^14cm-3,the shifts in threshold voltage are not obvious;only when the acceptor concentration induced is higher than 10^16cm-3,will the shifts of threshold voltage remarkably increase;the increase of threshold voltage,resulting from radiation induced acceptor,mainly contributes to the degradation in drain saturation current of the current-voltage （Ⅰ-Ⅴ） characteristic,but has no effect on the transconductance in the saturation area.
作者：
牛旭东李博宋岩张立宁何进Micro and Nano Electric Device and Integrated Group
The Key Laboratory of Integrated MicrosystemsPeking University Shenzhen Graduate School TSRC
Key Laboratory of MicroelectronicsDevices and Circuits of Ministry of EducationSchool of Electronics and Computer SciencePeking University
This paper presents the benchmark test results on the symmetry and continuity characteristics between BSIM4 from Berkeley and ULTRA-BULK from Peking University. It is shown that the industry standard model BSIM4 has a...
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This paper presents the benchmark test results on the symmetry and continuity characteristics between BSIM4 from Berkeley and ULTRA-BULK from Peking University. It is shown that the industry standard model BSIM4 has a series of the shortcomings of the continuity and symmetry, such as the charge, high-order current derivatives, and the trans-capacitances while the latest advanced surface-potential based MOSFET compact model, ULTRA-BULK, demonstrates all necessary continuity and symmetry characteristics, which are very important for analog and RF circuit design.
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