摘要:

Deep level transient spectroscopy, by means of capacitance transients, is applied to characterize deep carrier traps located in the depleted zone of a rectifying Te‐Se‐Cd structure. Preliminary observations, such as electron beam induced current and secondary electron and x‐ray emission, show that the depleted region is situated in thep‐type epitaxially grown Se film. Measurements of the thermal emission rate of trapped carriers are made in the 80–340 °K temperature range. From these, the existence of three deep hole traps in Se is demonstrated with the following values of the thermal activation energyET, capture cross section &sgr;e, and volume densityNT: 290 meV, 1.2×10−16cm2, 7.0×1013cm−3; 400 meV, 2.5×10−15cm2, 3.0×1013cm−3; 700 meV, 1.5×10−14cm2, 3.0×1014cm−3. The frequency dependence of the differential capacitance is measured between 100 Hz and 1 MHz and is attributed to a shallow hole trap (ET∼100 meV), with a high volume density in the 1019–1020cm−3range. This last result agrees with the conclusions deduced from thermally stimulated currents (TSC) experiments on the same type of material.

ISSN:0021-8979    

DOI:10.1063/1.328325

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

A detailed investigation of carrier relaxation in CdS0.5Se0.5, which has potential in ultrafast switching applications, has been carried out. It has been concluded from these investigations that there are three mechanisms for carrier relaxation in this material. At low 1.06‐&mgr;m radiation intensities the two‐photon‐induced photoconductivity decays slowly with a decay constant ?20 ms determined predominantly by bulk recombination of carriers. However, at high intensities this decay becomes very fast, with the recombination lifetime of the carriers estimated to be only a few nanoseconds. This drastic reduction in free‐carrier lifetime may be due to stimulated radiative recombination at high carrier densities. Single‐photon conductivity induced by low‐intensity 0.53‐&mgr;m radiation has been found to decay initially due to surface recombination of carriers.

ISSN:0021-8979    

DOI:10.1063/1.328326

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The technique of thermally stimulated conductivity is applied to the spectroscopy of shallow trap levels in semi‐insulting GaAs. Twelve previously unknown conductivity peaks are reported and the activation energy for thermal release of carriers trapped in the corresponding levels are determined with the aid of Urbach’s law. The obtained values are in good agreement with results available from infrared emission and photoconductivity. It is argued that most of these levels are responsible for the unresolved Gaussian band proposed by Leach.

ISSN:0021-8979    

DOI:10.1063/1.328327

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

We have studied two mechanisms thought to be responsible for the anomalous currents and resulting charge accumulation on the surface of polymeric dielectrics. First, we find the detailed normal electric fields on the plane surface of an insulating dielectric next to an electrode by conformal and numerical techniques. The polarization, as determined by the calculated field, is found to be consistent with experimental surface charge profiles; they both fall off inversely as the distance from the electrode. However, polarization is shown to give only a small contribution to the observed effect. Second, a transmission line model of the surface resistivity is studied. Previous work on this model is shown to be misleading. We establish that the surface resistivity must vary with distance from the electrode in order to account for the observed inverse time dependence of the current at long times. This unphysical requirement, and some contradictory experimental data, indicate that the present understanding of surface charging is inadequate.

ISSN:0021-8979    

DOI:10.1063/1.328328

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Oxide layers prepared with bromine water are found to increase the barrier height for Au‐InP Schottky diodes. Electrical characteristics are measured and the relationships between the preparation conditions and the diode parameters are examined. The typical value of the barrier height and the ideality factor are 0.83 eV and 1.1, respectively. Some instabilities are observed in the diode characteristics.

ISSN:0021-8979    

DOI:10.1063/1.328362

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Schottky barrier photodiodes have been fabricated onpHg1−xCdxTe (0.20<x<0.38) with aluminum and chromium as barrier metals. Various electrical characterizations have been carried out to determine barrier heights and the results are found to be in excellent agreement with Schottky thermionic emission theory. These photodiodes have also been used to determine the minority carrier lifetime and diffusion length inpHg1−xCdxTe.

ISSN:0021-8979    

DOI:10.1063/1.328363

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

Schottky barrier diodes are fabricated on silicon surfaces whose impurity concentrations are controlled by ion implantation techniques. The barriers are produced by electron beam evaporation or sputtering of the metal. The forward characteristics of the diodes show that the forward voltage of Schottky barrier diodes made by sputtering is 50–100 mV larger than those made by electron beam evaporation. Electron spectroscopy for chemical analysis measurements show that, for sputtering, the silicon oxide thickness at the interface between the metal film and silicon substrate is 0.2 nm thicker than for electron beam evaporation. Theoretical and experimental studies of Schottky barrier diodes in which the metal and silicon substrate are separated by a thin layer silicon oxide are reported.

ISSN:0021-8979    

DOI:10.1063/1.328364

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The interfacial layer theory considering the effects of the interface states and surface fixed charges is developed for the barrier height of the Schottky barrier diode with a thin uniformly doped surface layer. It is shown that the origins of the barrier height modification using the highly doped surface layer are mainly due to the increase of the electric field at the contact surface and the change of the interface properties. Design criterion for the maximum width of the highly doped surface layer is derived and calculated in detail for nickel barrier metal onn‐type silicon with the specificed interfacial layer conditions. Comparisons between the the developed expression of the barrier height reduction with respect to the ion dose and the experimental data of Shannonetal. are made, which tend to support the proposed model.

ISSN:0021-8979    

DOI:10.1063/1.328365

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

The change in potential energy of electrons and holes and the resulting band‐gap change caused by the image force have been calculated close to the insulator‐semiconductor interface. Some examples are given from which it appears that in metal‐insulator‐semiconductor (MIS) structures, as in Schottky diodes, the effects of the image force should not be overlooked.

ISSN:0021-8979    

DOI:10.1063/1.328366

出版商:AIP    

年代:1980

数据来源: AIP

摘要:

A mathematical model is presented for the retardation of the Werthamer functional for the Josephson tunneling junction to treat the current controlled case. Computational results concerning the current‐voltage characteristic make visible an enhanced hysteresis due to the nonlinear frequency response of the tunneling current. In addition, the irreversible flux transition in a SQUID is analyzed: the flux quantum transition time is found to be shorter than predicted by quasiadiabatic models.

ISSN:0021-8979    

DOI:10.1063/1.328367

出版商:AIP    

年代:1980

数据来源: AIP