Method for using a hardmask to form an opening in a semiconductor substrate

The present invention provides a method of forming a opening in a semiconductor dielectric layer. In an advantageous embodiment, the method comprises the steps of forming a hardmask layer on the dielectric layer wherein the hardmask layer has an etch rate less than an etch rate of the dielectric layer, forming a guide opening through the hardmask layer, forming a spacer within the guide opening that reduces a diameter of the guide opening and forming the opening in the dielectric layer through the guide opening. The method may further include the steps of depositing a conductive material in the opening and guide opening and over at least a portion of the hardmask layer that extends beyond the guide opening, and removing the hardmask layer and the conductive material layer that extend beyond the guide opening. In certain embodiments, the contact opening may be formed to a width equal to or less than 0.25 mu m.