| abstract |
PROBLEM TO BE SOLVED: To provide a semiconductor device using a high dielectric constant thin film, in particular, an ultra-thin gate insulating film layer indispensable for high integration and high speed of a MOSFET, and a high dielectric constant thin film used in a manufacturing process of a semiconductor device using a gate electrode. An etchant composition is provided. SOLUTION: The organic acid (preferably oxalic acid, citric acid, malonic acid, succinic acid, acetic acid or propionic acid) or an inorganic acid (preferably sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid or sulfamic acid). An etchant composition for a high dielectric constant thin film which is an aqueous solution containing a fluorine compound. |