Etchant and etching method

Abstract

Fluorescent probes represented by the general formula (I) wherein R<1> and R<2> are each hydrogen or a substituent for capturing a proton, a metal ion, or an active oxygen species; R<3> is a monovalent substituent except hydrogen, carboxyl, and sulfo; R<4> and R<5> are each hydrogen, halogeno, or alkyl; R<6> to R<9> are each alkyl; R<10> and R<11> are each hydrogen, halogeno, or alkyl; M<-> is a counter ion; and before the capture of a proton, a metal ion, or an active oxygen species, the combination of R<1>, R<2>, and R<3> gives the benzene ring to which they are bonded such a substantially high electron density as to make the compound substantially nonfluorescent, while after the capture of a proton, a metal ion, or an active oxygen species, the combination brings about such a substantial lowering in the electron density of the benzene ring to which they are bonded as to make the compound substantially highly fluorescent.

Description

technical field [0001] The present invention relates to an etchant for forming a pattern on a thin metal film by wet etching and an etching method using the etchant. More specifically, the present invention relates to an etchant and an etching method for etching a multilayer film including an aluminum alloy layer and a molybdenum-niobium alloy layer. Background technique [0002] Recently, electrodes and gate wiring materials used in semiconductor devices such as semiconductor elements and liquid crystal display elements are increasingly required to have a higher degree of microfabrication accuracy. In addition, it has been proposed to use metallic materials with lower electrical resistance. Examples of metal materials having lower resistance include aluminum and aluminum alloys, and these materials are being used more and more. [0003] Examples of techniques used to process thin films of the metal to form microstructures such as wiring include wet etching techniques in w...

AI Technical Summary

Problems solved by technology

Due to this unfavorable etching method, there is such a problem in the portion subjected to undercutting that since the multilayer film has a non-tapered sectional shape after etching, the gate insulating film (for example, SiN x ) insufficient coverage, resulting in poor insulation resistance, etc.

There is also such a problem that when the upper side metal layer is undercut, the exposed area of ​​the lower side metal layer in this part will increase.

Images