NONLINEAR RESISTANCE ELEMENT, PROCESS FOR PREPARING THE SAME AND LIQUID CRYSTAL DISPLAY

摘要

A process for preparing a nonlinear resistance element which comprises the steps of: forming a first conductive film composed of tantalum as a major component and tungsten as an additive on a substrate; anodizing the first conductive film using an electrolyte containing tungsten ions under such a condition that the pH of the electrolyte is adjusted according to the tungsten concentration of the first conductive film, thereby forming an insulating film on the first conductive film; and forming a second conductive film on the insulating film. The "polarity difference" of the nonlinear resistance element varies depending upon the tungsten concentration of the first metallic film and, at the same time, varies depending upon the pH of the electrolyte even when the tungsten concentration is the same. Therefore, the "polarity difference" can be brought to substantially zero by specifying the tungsten concentration of the first metallic film and setting the pH of the electrolyte used in the anodization according to the tungsten concentration. The electrolyte for the anodization is preferably an aqueous ammonium tungstate solution, and ammonium is preferably used as a pH regulator.