摘要:

Photoconducting red lead monoxide powder layers treated with a rhodamine B dye and deposited on interdigital electrodes are shown to have novel properties. The equilibrium dark current measured at 10 V may be reduced by applying a voltage pulse. Typically 200‐V pulses of 30 ms duration give a reduction of about 102times. The recovery from this nonequilibrium condition in the dark and under 600‐ nm illumination at intensities between 5×10−9and 5×10−7W/cm2is described. This behavior is discussed in terms of the depletion of grain‐grain contacts by the surrounding charge stored in surface states associated with the adsorbed dye molecules.

ISSN:0003-6951    

DOI:10.1063/1.89907

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The ability of SiO2precipitates to act as a source of process‐induced defects which can either beneficially getter unwanted impurities, or deleteriously interact with surface devices, has led to some confusion in interpreting the role of wafer oxygen content in device processing. This report presents a composite model which explains the many variables involved in oxygen precipitation and gettering phenomena.

ISSN:0003-6951    

DOI:10.1063/1.89908

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Phosphorus‐doped emitters have been formed by either conventional diffusion or implantation, anneal, and drive‐in processes. Transmission electron microscopy and measurements of transistor characteristics were made to evaluate the two processes. Comparison of structures with similar dislocation densities indicated that the dislocations in the implanted structures penetrated the emitter‐base sidewall, whereas the dislocations in the diffused structure were confined to the emitter region. The transistor with extended dislocations exhibited high leakage current and excess popcorn noise generating.

ISSN:0003-6951    

DOI:10.1063/1.89916

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

A native oxide layer of ∼30 A˚ is found on the Ga1−xAlxAs surface. Ion‐sputtering and ultrahigh vacuum (UHV) technologies are developed to fabricate an oxide‐free Schottky barrier from the (100) face of the compound semiconductor.

ISSN:0003-6951    

DOI:10.1063/1.89917

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

In Schottky‐barrier (Pt–nGaAs) Read‐type IMPATT diodes (Hi‐Lo or Lo‐Hi‐Lo) it is now well known that the thermionic field‐effect carrier injection (TFE) can decrease the diode microwave performances but also improve the noise properties under large signal levels. We present an experimental study to determine the TFE current which sets off the avalanche for voltage operation corresponding to oscillation or amplification conditions by measuring the back‐bias effect in a pulse operation mode. Then using the tunnel current which has been checked by the present method, the variation of the optimum frequency operation for a high‐low doping profile diode is calculated.

ISSN:0003-6951    

DOI:10.1063/1.89918

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The deep energy level of the isotope34S in the upper half of the energy gap of silicon is examined by isothermal transient capacitance measurements on ion‐implantation‐predeposited diode structures. The resulting energy level atEc−0.512 eV is found to be 0.014 eV closer to the conduction band edge than the corresponding deep level for the isotope32S in similarly prepared samples. The existence of an isotope shift for the deep sulfur level is interpreted as implying vibronic coupling between the electronic states of the sulfur center and the silicon lattice.

ISSN:0003-6951    

DOI:10.1063/1.89919

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

The distribution coefficients for the growth of lattice‐matched InGaAsP on (100) ‐InP substrates in the 1.15–1.31‐&mgr;m spectral range have been determined. These results have been used in the growth of heterojunction photodiodes with quantum efficiencies ⩾48% at 1.27 &mgr;m.

ISSN:0003-6951    

DOI:10.1063/1.89920

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Photoluminescence time‐decay measurements on Ga0.5Al0.5As/GaAs double heterostructures were made over a wide range of GaAs active layer thickness and doping levels at room temperature. Observed decay times &tgr; in variously doped GaAs samples range from 10 to 450 nsec. Effects of self‐absorption of luminescence and doping level are demonstrated for GaAs layer thicknessd≳1 &mgr;m. Ford<1 &mgr;m, the observed decay times are nearly independent of doping level and vary almost linearly withd. The data are interpreted in terms of a small interfacial recombination velocity (Si=450±100 cm/sec) at the Ga0.5Al0.5As/GaAs interface. The value ofSidetermined here is an average over the doping levels examined.

ISSN:0003-6951    

DOI:10.1063/1.89921

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Transient capacitance measurements have been performed on Schottky barriers onn‐GaAs containing the deep electron trap associated with oxygen, as a function of hydrostatic pressure. It is found that the oxygen level separates from the conduction band at a linear rate of 3.8±0.3 meV/kbar. From a comparison with published optical data we conclude that most of this variation comes from a pressure‐dependent Frank‐Condon shift and that the unoccupied level separates very little from the valence band.

ISSN:0003-6951    

DOI:10.1063/1.89887

出版商:AIP    

年代:1978

数据来源: AIP

摘要:

Comprehensive measurements of the parameters characterizing an rf‐biased SQUID as a linear twoport are described. The behavior of the device corresponds in detail to the predictions of a recently published model of SQUID operation and is unexpectedly similar to that of a conventional reactive parametric amplifier. The measurements have been used to make the first reliable predictions of the noise temperature and optimum source impedance of an rf‐biased SQUID.

ISSN:0003-6951    

DOI:10.1063/1.89888

出版商:AIP    

年代:1978

数据来源: AIP