Quasimetallic photoconductivity produced by the absorption of picosecond optical pulses in silicon transmission line structures has been used to devise electronic switches and gates which can be turned on and off in a few picoseconds. Electrical signals as large as 100 V can be switched by a few microjoules of optical energy. The switching speed was measured by correlating the response of two transmission gates in tandem, each having an aperture time of 15 psec.

Picosecond optoelectronic switching and gating in silicon

An important aspect of the large expansion in the development and production of solid-state devices has been the demand for more sophisticated techniques for determining the electrical properties of semiconductors, especially silicon and the III-V compounds. A very wide range of measurement techniques now exists and it is the purpose of this article to review those techniques which are in widespread use or which show promise for future application, and at a time for continuing innovation in this area, to indicate present trends and material problems which may arise in the near future.

https://iopscience.iop.org/article/10.1088/0034-4885/41/2/001/pdf

The electrical characterisation of semiconductors

The present review gives an account of a number of investigations that have been recently carried out in the Semiconductor Laboratory Pretzfeld, Siemens AG. The switching processes in power rectifiers from the forward into the reverse state differ greatly from the corresponding process predicted by low-level theory. This result is caused not only by the fact that the conditions are different for high injection, but in addition, the sweeping out of the charge carriers takes place from two sides, owing to the nearly uniform concentration distribution in the forward state. Because of the unequal electron and hole mobilities, the impurity distribution on the side of the p contact is of much greater importance than at the n contact; if there is no p-n junction on this more important side, then the stored change can be swept out without much voltage buildup (example: rectifiers from uniformly doped p material). If, on the other hand, a p-n junction lies before the p contact (example: rectifiers from uniformly doped n material) then tbe reverse recovery current decays soon but slowly, and the switching process takes a longer time. This fact also contributes to the relatively long turn-off time of the thyristors.

Reverse recovery processes in silicon power rectifiers

Measurement of microwave and UHF signals is often done with sampling techniques. In this paper, the techniques and technology of sampling of electrical signals is reviewed from 1950 to the present. It includes both references to the open literature, as well as an extensive review of relevant patents. It also provides an overview of sampling applications and the use of computer technology to compensate and correct for errors in the sampling process.

50 years of RF and microwave sampling

A simple charge-controlled switching model describes most fundamental aspects of the step recovery diode. However, it is shown that switching speed and the associated loss are related to the width of the i layer and to the doping level. A switching model appropriate for general computer use is given, and examples of its application are shown in pulse and harmonic generator circuits.

Physical modeling of the step recovery diode for pulse and harmonic generation circuits

The design theory for a new range of p-n junction applications is presented. The applications include pulse generation, wave shaping, and harmonic generation. The diodes are characterized by a very abrupt interruption of reverse current in the turn-off transient and are approximately ideal nonlinear capacitors. The abrupt interruption of current in the reverse transient is related to the impurity profile in the junction. An estimate is given of the duration of the abrupt phase. In addition, the role of parasitic elements such as inductance, capacitance, and series resistance is discussed in relation to a particular representative circuit. In typical cases, the abrupt turn-off phase lasts for a time of the order of 10-9 sec. Transitions in excess of 100 v or an ampere are readily obtained.

J. L. Moll

Papers

P-N Junction Charge-Storage Diodes