METHOD FOR FABRICATING CAPACITOR BY WET ETCH METHOD AND ELECTROCHEMICAL DEPOSITION METHOD

摘要

PURPOSE: A method for fabricating a capacitor by a wet etch method and an electrochemical deposition method are provided to form a ruthenium thin film of a better quality than that of a ruthenium thin film fabricated by a metal organic deposition method by performing an electrochemical deposition process. CONSTITUTION: An insulation layer on a substrate(20) is selectively etched to form a contact hole of the capacitor. A contact medium including a nitride is formed in the contact hole so that the upper step of the contact hole is left. A ruthenium seed layer(25) for an electrochemical deposition method is formed to fill the remaining upper step of the contact hole while covering the insulation layer. A capacitor sacrificial layer in which a region overlapping the contact hole is open is formed on the ruthenium seed layer. A ruthenium layer is formed as a capacitor electrode in the open region of the sacrificial layer by an electrochemical deposition method. The sacrificial layer is eliminated. The ruthenium seed layer exposed by the removal of the sacrificial layer is etched by using an aqueous solution including Ce(NH4)2(NO3)6.