A method for producing a small feature in a semiconductor device includes depositing a mask material on an unpatterned layer in which an ultra-narrow opening is to be formed, and then masking and etching the mask material to form a narrow opening. A spacer material is then deposited on the mask material, with spacer material settling into and covering the narrow opening. Thereafter, a portion of the spacer material is removed by etching, leaving some spacer material in the opening but exposing an ultra-narrow region of the first layer at the bottom of the opening in the mask material. The ultra-narrow region left uncovered by the spacer material is smaller than the narrow region in the mask material. Once the ultra-narrow region is uncovered, material in the first layer is removed through the ultra-narrow region, by anisotropic etching, for example, to form an ultra-narrow opening in the first layer.