摘要:

Computer simulations ofn+-n-n+transferred-electron devices predict a frequency multiplier mode with favourable properties as a power source for the millimetre band. The mode is related to the l.s.a. ocillator, but waveform distortion allows operation to a considerably higher frequency. Second-harmonic generation is much more efficient than generation of higher harmonics. The dependence of the multiplier characteristics on carrier density, device length and frequency are analysed for two models of GaAs differing in the strength of the intervalley scattering rate. Comparison indicates that strong intervalley scattering leads to a higher frequency limit. Estimates of the power and impedance parameters of devices are made as precursors to circuit design.

DOI:10.1049/ip-i-1.1980.0032

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The dependence of minority-carrier injection currentJpon applied forward-bias voltage of metalpolysilicon contacts has been calculated within a general treatment of the recombination at grain boundaries. A uniform distribution of interface states in energy at the grain boundaries is assumed throughout. It is found approximately thatJp̃ exp (q V/KT) for (grain-boundary) recombination limited by the supply of minority carriers,Jp̃ exp (q V/KT) or exp (q V/2KT) for high and low grain-boundary interface state densities for recombination limited by the supply of majority carriers, andJp̃ exp (3qV/4KT) for intrinsic recombination (limited equally by holes and electrons). Electrostatic effects of grain-boundary interface states, resulting in a bias dependence of grain-boundary barrier height øg, are significant for interface state densitiesNis> 1010–1011cm−2V−1. depending upon the doping within the grains. The effective diffusion length for the injected minority carriers also shows an appreciable bias dependence, especially for intrinsic recombination, and for majority-carrier limited recombination at high øgand lowNis.Minority-carrier injection dominates the dark current (as it does in ap-njunction) for Schottky-barrier height øb> 0.8 V, for typical grain size d≃10−3cm, interface state densitiesNis≃1013cm−2V−1, and relatively low doping Nd≃1014cm−3.

DOI:10.1049/ip-i-1.1980.0034

出版商:IEE    

年代:1980

数据来源: IET

摘要:

This paper describes a V-groove isolated b.i.f.e.t. technology suitable for micropower integratedcircuit fabrication. The V-groove isolation technique offers considerable advantages in area and performance over standard junction isolated technology. The technology provides an ideal combination of active elements which include low pinchoff j.f.e.t.s and bipolar transistors. The characteristics of the devices as well as typical applications of the technology are described.

DOI:10.1049/ip-i-1.1980.0036

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The bistable behaviour displayed by the m.i.-n-p+switch (designated m.i.s.s.: an acronym for metal-insulator-silicon switch) can be electrically controlled via a third gate terminal. This three-terminal device is named m.i.s.t. for metal-insulator-semiconductor thyristor. The function of the gate control is to strengthen, or weaken, the intrinsic regeneration within the m.i.s.s., by means of majority-carrier injection, minority-carrier injection, or electrostatic control of the n-p+junction voltage. The previously reported feedback model of the m.i.s.s. device is extended to cover the three-terminal m.i.s.t. Simple closed-form expressions for the gate-control efficiency are derived for the two modes of operation of the m.i.s.t. It is shown that the gate-control efficiency is largest for the avalanche-mode m.i.s.s. with a majority-carrier injecting gate.

DOI:10.1049/ip-i-1.1980.0037

出版商:IEE    

年代:1980

数据来源: IET

摘要:

N-channel m.o.s. transistors have been operated at an ambient temperature of 77K withVDS=VGSto maximise the generation of high-energy (‘hot’) electrons in the channel. All the major transistor parameters exhibited substantial shifts which can be ascribed to two degradation mechanisms, namely the well known trapping of electrons in the gate oxide near the drain, and the generation of lattice defects in the semiconductor.

DOI:10.1049/ip-i-1.1980.0038

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The results of extensive measurements on metal-gallium arsenide Schottky-barrier diodes in a waveguide mixer are presented, with emphasis on cooled, low-noise operation. Aspects of diode design and manufacture are reviewed, particularly with a view to the better understanding of noise generation in the diode. It appears that previous current-transport and noise-generation models require modification.

DOI:10.1049/ip-i-1.1980.0039

出版商:IEE    

年代:1980

数据来源: IET

摘要:

Transient analysis simulations are used to investigate the m.o.s. device scaling theorem. Calculations are presented of the power-delay curves of loaded static NOR gates for two sets of devices: one, a control device with seven micron channel length, and the other scaled from the control by 0.6. It is shown that, when devices are scaled correctly, circuit performance scales according to the prediction of the scaling theorem. Furthermore, considerations are presented on circuit performance degradation if power-supply voltages are not scaled similarly to device dimensions.

DOI:10.1049/ip-i-1.1980.0040

出版商:IEE    

年代:1980

数据来源: IET

摘要:

The Monte Carlo particle model of GaAs Schottky-barrier field-effect transistors developed at Reading has been applied to describe a new f.e.t. geometry in order to establish the noise performance. The effect of introducing ap-type layer between the epilayer and the substrate is examined and the d.c. characteristics obtained are presented. By varying the thicknesses of both the epilayer and the buffer layer, as well as the doping of the latter, an optimal design has been arrived at. However, the transconductance of this optimal design is very sensitive to the thickness of the epilayer.

DOI:10.1049/ip-i-1.1980.0041

出版商:IEE    

年代:1980

数据来源: IET

摘要:

Isotype heterojunctions make it possible to produce new microwave devices. At present, technological problems are still important and often, there is not a full understanding of their behaviour. In the paper, the fundamental parameters ofnGe -nGaAs heterojunctions are determined from the frequency variations of their impedancesZ(ω, V). To account for the large impedance variations, a heterojunction model is proposed. By using the values of the capacitance and the parallel conductance for different frequencies, the fundamental parameters of several isotype heterojunctions are then determined. The calculated characteristics agree well with the experiment.

DOI:10.1049/ip-i-1.1980.0042

出版商:IEE    

年代:1980

数据来源: IET

摘要:

This paper describes the conduction mechanisms in r.f.-sputtered Schottky-barrier solar cells incorporating hydrogenated amorphous Si (a-Si-H). The illumination and temperature dependence of the open-circuit voltage(VOC) and the short-circuit current (Js—c) of the cells are discussed. The properties of the cells containing optimum and nonoptimum a-Si-H and various Schottky metals are contrasted. The temperature dependence of the forward characteristics of the cells is also examined. Three different conduction mechanisms in the Schottky-barrier cells are identified and described.

DOI:10.1049/ip-i-1.1980.0043

出版商:IEE    

年代:1980

数据来源: IET