METHOD FOR FORMING VIA HOLE IN SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a via hole in a semiconductor device is provided to be capable of preventing damage of a lower metal wiring by using an additional sacrificial layer. CONSTITUTION: A sacrificial layer(23) and an intermetal dielectric(24) are sequentially formed on a substrate(20) having a lower metal line(21). A hard mask(25A) is formed on the intermetal dielectric(24). The intermetal dielectric(24) is entirely etched, and the sacrificial layer(23) is partially etched using the hard mask(25A) as a mask. After removing the hard mask(25A), then a via hole is formed by etching of the sacrificial layer(23), wherein the sacrificial layer(23) has relatively high etching selectivity compared to the hard mask(25A). Preferably, polysilicon is used as the hard mask(25A) and nitride is used as the sacrificial layer(23).