| abstract |
Tin oxide films are used as mandrels in semiconductor device fabrication. In one implementation, the process begins by providing a substrate having a plurality of protruding tin oxide features (mandrels) present on an exposed etch stop layer. Next, a layer of conformal spacer material is formed on both the horizontal surfaces and the sidewalls of the mandrel. The spacer material is then removed from the horizontal surface, thereby exposing the tin oxide material of the mandrel without completely removing the spacer material present on the sidewalls of the mandrel (eg, leaving at least 50% of its original height on the sidewalls, eg at least 90%). Next, the mandrel is selectively removed (eg, using a hydrogen-based etch chemistry) while leaving the spacer material present on the sidewalls of the mandrel. The resulting spacers can be used to pattern etch stop layers and underlying layers. |