Method for enhancing etching selectivity of metal silicide film/polysilicon film and method for etching stacked film of metal silicide film and polysilicon film using the same

摘要

The present invention provides an etching method capable when etched by plasma etching polycide film, increasing the metal silicide film is etch selectivity to the polysilicon film. Applying the present invention by applying a bias power to a plasma source, but power is supplied to the metal silicide film is plasma etching, the substrate to an etching chamber, to accelerate the ions of the etching gas; and a plasma source power to the etch stop suicide metal is continued, and the substrate a by applying applied only power in the bias range the power is not applied to either the etching gas ions are accelerated were, the etching gas is adsorbed by chemical, the metal silicide film, is made by repeating the steps of to oxidizing exposed polysilicon film.; According to the present invention, it is possible to form a film polycide film is plasma etched during the modulation bias power supply by selectively etching only on the exposed polysilicon film, a metal silicide film increases etching selectivity of the polysilicon film. Accordingly, it is possible to prevent damage to the substrate according to the polycide film is etched when the polysilicon film over etching can improve the reliability of the semiconductor device.