摘要:

This paper considers the mechanism of optical switching and the possible utilisation of the metal tunnel-insulatorn–p+silicon device in optical communication systems. The pertinent design approaches are described. Under optical excitation, photo holes and electrons generated in the surface depletion region, or within diffusion range, will eventually be separated by the electric field and produce an increment in the forward current. Those hole-electron pairs generated in the junction region, or within diffusion range, produce a photovoltaic increase in thep+–njunction bias. Switching is induced optically, as it is electrically, by the build up of holes at the insulator-semiconductor interface. This paper employs the 1-dimensional diffusion equation to derive the light-generated minority carrier distributions and diffusion currents in the neutralnandp+regions, together with the currents in the surface andp+–njunction depletion regions. The calculated values of both the drift and diffusion currents compare favourably with those observed experimentally

DOI:10.1049/ij-ssed.1979.0019

出版商:IEE    

年代:1979

数据来源: IET

摘要:

Microwave properties of GaAs and InP punchthrough diodes in the millimeter-wave range are investigated in this paper. By means of an exact large-signal computer simulation, taking into account the carrier velocity-field dependence, diffusion phenomena and a realistic doping profile, the influence of the negative differential mobility on oscillation performance is studied. Large negative resistances can then be obtained with well-designedn+–p–n–n+structures. At a frequency of 40 GHz, optimum output powers of 20mW and 120mW have been calculated for GaAs and InP materials, respectively. The corresponding non-linear resistances are −7Ω and −7.5 Ω. An interesting use can then be expected as a self-oscillating mixer or as Doppler radar in the millimetre-wave range.

DOI:10.1049/ij-ssed.1979.0020

出版商:IEE    

年代:1979

数据来源: IET

摘要:

Experiments show that there is a strong influence of the clock waveform on the performance on c.c.d. split-electrode transversal filters if the splits are defined by means of channel-stop islands, which do not allow any surface-potential equilibration along the gate. The effect is absent when this equilibration is allowed by means of a suitably placed floating diffusion which connects the channels below the two portions of the split electrode. The process is modelled with an effective difference of threshold voltages between the two sections of the electrode controlling the transfer. It is thus possible to predict the dependence of the stopband attenuation of the filter on the slope of the clock pulses.

DOI:10.1049/ij-ssed.1979.0021

出版商:IEE    

年代:1979

数据来源: IET

摘要:

This paper studies the nature and degree of variation in current gain caused by perturbations in processing and material parameters in normal andI2L(inverse) transistors, formed by the double-diffusion process. The influence of predeposition and drive-in cycle, surface recombination velocity, emitter contact area and epitaxial-layer concentration has been estimated. It is shown that it is possible to recover a change in gain caused by perturbation in a particular parameter. Current-gain variability is found to be a characteristic of device design. It is desirable to optimise the design, both from the viewpoint of the specified gain and its expected variability.

DOI:10.1049/ij-ssed.1979.0024

出版商:IEE    

年代:1979

数据来源: IET