To reveal the internal physics of the low-temperature mobility of two-dimensional electron gas （2DEG） in Al- GaN/GaN heterostructures, we present a theoretical study of the strong dependence of 2DEG mobility on Al c...
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To reveal the internal physics of the low-temperature mobility of two-dimensional electron gas （2DEG） in Al- GaN/GaN heterostructures, we present a theoretical study of the strong dependence of 2DEG mobility on Al content and thickness of AlGaN barrier layer. The theoretical results are compared with one of the highest measured of 2DEG mobility reported for AlGaN/GaN heterostructures. The 2DEG mobility is modelled as a combined effect of the scat- tering mechanisms including acoustic deformation-potential, piezoelectric, ionized background donor, surface donor, dislocation, alloy disorder and interface roughness scattering. The analyses of the individual scattering processes show that the dominant scattering mechanisms are the alloy disorder scattering and the interface roughness scattering at low temperatures. The variation of 2DEG mobility with the barrier layer parameters results mainly from the change of 2DEG density and distribution. It is suggested that in AlGaN/GaN samples with a high Al content or a thick AlGaN layer, the interface roughness scattering may restrict the 2DEG mobility significantly, for the AlGaN/GaN interface roughness increases due to the stress accumulation in AlGaN layer.
A 12-bit 20MS/s cost-efficient pipelined analog-digital converter is presented. A dedicated first stage is proposed to eliminate the need of front-end SHA. Passive capacitor error-averaging technique (PCEA) and opamp ...
This paper proposes a novel calibration technique and its application on an adaptive-bandwidth PLL. The new calibration method reduces calibration time by using an improved dual-edge phase detector to compare frequenc...
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This paper proposes a novel calibration technique and its application on an adaptive-bandwidth *** new calibration method reduces calibration time by using an improved dual-edge phase detector to compare frequency dif...
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ISBN:
(纸本)9781424421855
This paper proposes a novel calibration technique and its application on an adaptive-bandwidth *** new calibration method reduces calibration time by using an improved dual-edge phase detector to compare frequency difference *** maximum calibration time is less than five comparison *** the calibration technique and an adaptive bandwidth,the PLL can maintain optimal performance during the whole working *** proposed circuit has been implemented in 0.18um CMOS logic *** show that the calibration time is less than 1.2μs,and the total locking time is less than 3μ*** PLL has good jitter performance within its operating range from 860MHz to 2.1GHz.
In this paper, we propose a simple but effective method to reduce the power in the design of the Speed Negotiation Algorithm(SNA). Based on thoroughly analyzing the algorithm and the results of simulation, we identify...
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A low power high speed Read-Out Integrated Circuit (ROIC) for a short-wave Infra-Red Focal Plane Array (IRFPA) is designed as a prototype for 1024x1024 image system. Ripple integration and readout scheme as well as hi...
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作者：
张韬吕红亮张义门张玉明叶丽辉Microelectronics Institute
Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices of Ministry of Education Xidian University Xi' an 710071
With the combined use of the drift-diffusion （DD） model, experiment measured parameters and small-signal sinusoidM steady-state analysis, we extract the Y-parameters for 4H-SiC buried-channel metal oxide semicon- du...
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With the combined use of the drift-diffusion （DD） model, experiment measured parameters and small-signal sinusoidM steady-state analysis, we extract the Y-parameters for 4H-SiC buried-channel metal oxide semicon- ductor field effect transistors （BCMOSFETs）. Output short-circuit current gain G and Mason＇s invariant U are cMculated for extrapolating unity current gain frequency in the common-source configuration fT and the maximum frequency of oscillation fmax, respectively. Here fT = 800 MHz and fmax= 5 GHz are extracted for the 4H-SiC BCMOSFETs, while the field effect mobility reaches its peak value 87cm2/Vs when VGs = 4.5 V. Simulation results clearly show that the characteristic frequency of 4H-SiC BCMOSFETs and field effect mobility are superior, due to the novel structure, compared with conventional MOSFETs.
A front-end ASIC for semiconductor radiation detectors is presented. It is composed of a Charge Sensitive Amplifier (CSA), a pulse shaper, and a Peak Detect and Hold (PDH) circuit. Poly-resistor is used as source dege...
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This paper presents a UHF band (840MHz-925MHz) RFID reader transceiver design for the protocols of EPC Class-1 Gen-2 and ISO/IEC 18000-6C. The architecture and modules for the proposed transceiver are described and im...
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A thermal model of 4H-SiC MESFET is developed based on the temperature dependences of material parameters and three-region I - V model. The static current characteristics of 4H-SiC MESFET have been obtained with the c...
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A thermal model of 4H-SiC MESFET is developed based on the temperature dependences of material parameters and three-region I - V model. The static current characteristics of 4H-SiC MESFET have been obtained with the consideration of the self-heating effect on related parameters including electron mobility, saturation velocity and thermal conductivity. High voltage performances are analysed using equivalent thermal conductivity model. Using the physicalbased simulations, we studied the dependence of self-heating temperature on the thickness and doping of substrate. The obtained results can be used for optimization of the thermal design of the SiC-based high-power field effect transistors.
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