Pitch reduction technology using alternating spacer depositions during the formation of a semiconductor device and systems including same
A method for patterning a layer increases the density of features formed over an initial patterning layer using a series of self-aligned spacers. A layer to be etched is provided, then an initial sacrificial patterning layer, for example formed using optical lithography, is formed over the layer to be etched. Depending on the embodiment, the patterning layer may be trimmed, then a series of spacer layers formed and etched. The number of spacer layers and their target dimensions depends on the desired increase in feature density. An in-process semiconductor device and electronic system is also described.
1. A method used during fabrication of a semiconductor device, comprising:
providing a layer to be etched;
forming a sacrificial patterning layer over the layer to be etched, wherein the sacrificial patterning layer comprises a plurality of segmented portions having at least first and second cross sectional sidewalls;
forming a plurality of sacrificial first spacers, with one spacer formed on each sidewall of each segmented portion of the sacrificial patterning layer;
removing the sacrificial patterning layer;
forming a conformal second spacer layer over the plurality of sacrificial first spacers;
removing a portion of the conformal second spacer layer to form a plurality of second spacers on the sacrificial first spacers, wherein the second spacers have different elevational thicknesses;
subsequent to forming the second spacers, removing the sacrificial first spacers; and
etching the layer to be etched using the second spacers as a pattern.
2. The method of claim 1 further comprising:
forming a third spacer layer over the first spacers and on the second spacers;
removing a portion of the third spacer layer to form third spacers;
removing the second spacers and leaving the first and third spacers; and
etching the layer to be etched using at least the first and third spacers as a pattern, wherein the first and third spacers have different elevational thicknesses.
3. The method of claim 1 further comprising:
providing a microprocessor; and
providing an electrical pathway between the semiconductor device and the microprocessor to facilitate electrical communication therebetween.
4. The method of claim 1 wherein the second spacers each define non-planar tops.
5. The method of claim 1 wherein the first spacers are the same height.
6. The method of claim 5 wherein the first spacers each define a non-planar tops.
7. The method of claim 1 , wherein the sacrificial patterning layer comprises a photoresist layer, wherein the photoresist layer defines a height above a sacrificial first spacer height.
8. A method, comprising:
forming a sacrificial patterning material over a material to be etched, wherein the sacrificial patterning material comprises a plurality of segmented portions having at least first and second cross sectional sidewalls;
forming a plurality of sacrificial first spacers, with one spacer formed on each sidewall of each segmented portion of the sacrificial patterning material;
removing the sacrificial patterning material;
forming a conformal silicon dioxide second spacer material over the plurality of sacrificial first spacers;
removing a portion of the conformal silicon dioxide second spacer material to form a plurality of second silicon dioxide spacers on the sacrificial first spacers, wherein the second silicon dioxide spacers have different elevational thicknesses;
subsequent to forming the second silicon dioxide spacers, removing the sacrificial first spacers; and
etching the material to be etched using the silicon dioxide second spacers as a pattern.