Controlled Formation of ZnO Fine-pattern Transparent Electrodes by Wet-Chemical Etching

摘要

Quality control of the chemicals used to form patterns in GZO films is very important when producing fine patterns. For example, using a TMAH (tetramethylammonium hydroxide) aqueous solution as a developer for a positive-type photoresist, precise control of its pH value in the range from 12.0 to 13.2 is essential when forming fine, dense patterns of lines and spaces a few micrometers wide in GZO films. A zinc-oxy-carbonate passivation layer was formed on the surface of GZO films by reaction with carbon dioxide absorbed from the atmosphere into the acid etchant. The passivation layer assisted the formation of a 2-(im-wide fine pattern because it reduced the etching rate of GZO in the acidic etchant.