Systems and methods include introducing a semiconductor wafer into a process chamber. An etching chemistry is injected into the process chamber to etch a patterned layer and to release free-standing nanostructures on the semiconductor wafer. The etching chemistry includes a supercritical or liquid carbon dioxide fluid and an etching solution. The semiconductor wafer is rinsed by flooding a supercritical or liquid carbon dioxide fluid into the process chamber. The semiconductor wafer is dried by venting out supercritical or liquid carbon dioxide fluid from the process chamber.