Patent ID: 6100014
Filing Date: 2000-08-08
Classification: G03F

Abstract:
A method for forming an opening in a dielectric layer formed over a semiconductor substrate, comprising the steps of:coating a base photoresist layer over the dielectric layer;performing a photolithographic process to remove a selected part of the base photoresist layer lies directly over the part of the dielectric layer where the intended opening is located;performing a conformational coating process to coat a silylatable photoresist layer over the base photoresist layer to a controlled predefined thickness;performing a silylation process on the silylatable photoresist layer so as to form a silylated photoresist layer over all the exposed surfaces of the base photoresist layer;performing a first etching process on the silylated photoresist layer, with the remaining part of the silylated photoresist layer serving as silylated sidewall spacers on the base photoresist layer;with the combined structure of the base photoresist layer and the overlying silylated sidewall spacers serving as mask, performing a second etching process on the dielectric layer to etch away the unmasked part of the dielectric layer to form the intended opening in the dielectric layer; andremoving the combined structure of the base photoresist layer and the overlying silylated sidewall spacers.