摘要:

By means of the Monte Carlo particle model, the transport properties of bulk intrinsic GaAs have been studied for a uniform electric field ranging from 0 to 20 MV/m. As this model is based on first principles, a profound insight into the physics of the material has been obtained. The –,LandXminima of the conduction band have been treated like separate bands in the effective mass approximation. The energy distribution has been found to deviate increasingly from the displaced Maxwellian as the field increases; there are additional peaks due to transfer of carriers between the different minima of the conduction band.The time and path of free flights have been analysed for each minimum during steady state and found to be more complex than that described by simple theory based on current drift and relaxation times. The population ratio and the relative strengths of the principal scattering mechanisms have also been obtained against the electric field.By assuming an initial state of zero field and thermal distribution of the conduction electrons, the evolution of the population of the different minima and of the drift velocities have been followed until the steady state has been reached. This information may prove valuable in improving the diffusion type numerical modelling of semiconductor microcomponents where nonstationary transport is significant.

DOI:10.1049/ip-i-1.1986.0009

出版商:IEE    

年代:1986

数据来源: IET

摘要:

A GaAsn+iδp+in+bulk barrier transistor with an ultra-thinp+Al0.2Ga0.8As base was fabricated by molecular beam epitaxy. It is found that the barrier height can be modified by the ΔEcfor the conduction band barrier and by the ΔEvfor the valence band barrier, in addition to the planar doped bulk barrier. Both the base-emitter bias voltage and the incident light intensity can modulate the collector current.

DOI:10.1049/ip-i-1.1986.0010

出版商:IEE    

年代:1986

数据来源: IET

摘要:

A novel transformation technique has been devised which enables the rapid evaluation of the key MOS transistor parameters, threshold voltage, gain and mobility degradation factor without recourse to the inaccurate compromise approaches previously used. In the paper, the previous methods are reviewed to highlight the errors which can occur, and then the new technique detailed. Extensions to the technique are discussed to enable three of the global parameters to be determined. Finally, a test block is described which is suitable for the parameter extraction routine developed.

DOI:10.1049/ip-i-1.1986.0011

出版商:IEE    

年代:1986

数据来源: IET

摘要:

An automatic channel router for integrated circuits is presented. It operates, as is commonplace with this kind of router, in two stages: the global router is based on a relative placement of subcell instances and it is executed only once during the layout generation process of a specific cell. The detailed router, however, operates in an iterative mode. Initially, the subcell instances are placed as close as possible, in accordance with the given relative placement specification. This absolute placement is then gradually expanded until the channels become properly dimensioned so as to hold all the connections allocated to them at the preceding global routing stage. The expansion is driven by feedback information at the end of each iteration about the failures to route connections in the currently available space.

DOI:10.1049/ip-i-1.1986.0013

出版商:IEE    

年代:1986

数据来源: IET

摘要:

A new dynamic random access memory cell, which incorporates three diodes in a composite structure, is proposed and investigated. In the 3-diode memory cell, one diode serves as a storage capacitor and the others serve as switches. The cell requires only three interconnect lines and can be fabricated with standard bipolar technology. The write, read, and standby operations of the cell are analysed and simulated.

DOI:10.1049/ip-i-1.1986.0014

出版商:IEE    

年代:1986

数据来源: IET