[en] The spontaneous and ion enhanced etching of sputter deposited tungsten films has been studied. The etch rates have been measured as a function of various etch parameters with striking differences found as a function of sample temperatures. The spontaneous etch rate is found to be totally suppressed at temperatures below 170 K, and concomitantly the ion enhanced etch rate is increased. With these two points in mind, it is shown that ion beam enhanced etching of W with XeF₂ at moderately low temperatures could be used to greatly improve the ratio of the ion enhanced etch rate over the spontaneous etch rate. This unique condition could be used to achieve high aspect ratio structures with vertical walls and opens up the possibility of direct ion beam pattern definition