Bbc Brown, Boveri & Company, Limited

Abb Schweiz Ag

Hans Rudolf Zeller

Terry J Scheffer

Stefan Linder

In a method for fabricating a semiconductor component with a cathode and an anode from a wafer, the wafer is first provided with a stop zone, thereupon treated on the cathode side and only then reduced in its thickness, so that all that remains of the stop zone is a tail barrier zone. In this case, the stop zone is doped and reduced to the tail barrier zone in such a way that a quantitative optimization of the fabrication method and thus of a thinned semiconductor element is made possible. In said quantitative optimization, diverse parameters and their relation to one another are taken into account, in particular a dopant area density of a tail barrier zone, a dopant density at an anodal surface of the tail harrier zone, a dopant density of a base, a characteristic decay length or slope of the doping profile of the tail barrier zone, and also a thickness of a base&mdash;resulting from the wafer&mdash;from anode to cathode.

Method for fabricating semiconductor component with an optimized thickness

A liquid crystal display is described for displaying dark signs on a light background in accordance with the guest-host principle without polarizers. The display includes parallel plates the insides of which are provided with an orientation layer which produces a homoeotropic orientation in an adjacent liquid crystal mixture. The liquid crystal mixture is formed primarily of a nematic liquid crystal having a high negative dielectric anisotropy and, secondarily, of an optically active substance. The proportion of the optically active substance is smaller than the quantity which would cause a spontaneous formation of a twisted structure in the liquid crystal mixture in the field-free state. The liquid crystal mixture is thus homoeotropically oriented and transparent throughout in the field-free regions, and is planar-cholesteric and absorbing in the activated regions.

Liquid crystal display

Electrode for a controllable electrochromic indicator device with an electrochromic layer between a transparent first and a second electrode, the second electrode having a porous solid impregnated with a liquid electrolyte.

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Birr, Switzerland

Hans Rudolf Zeller