Abstract: Methods of selectively etching tungsten oxide relative to tungsten, silicon oxide, silicon nitride and/or titanium nitride are described. The methods include a remote plasma etch formed from a fluorine-containing precursor and/or hydrogen (H2). Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the tungsten oxide. The plasmas effluents react with exposed surfaces and selectively remove tungsten oxide while very slowly removing other exposed materials. In some embodiments, the tungsten oxide selectivity results partly from the presence of an ion suppression element positioned between the remote plasma and the substrate processing region. The ion suppression element reduces or substantially eliminates the number of ionically-charged species that reach the substrate.

Abstract: A method of etching silicon oxide from a multiple trenches is described which allows more homogeneous etch rates among trenches. The surfaces of the etched silicon oxide within the trench following the etch may also be smoother. The method includes two dry etch stages followed by a sublimation step. The first dry etch stage removes silicon oxide quickly and produces large solid residue granules. The second dry etch stage remove silicon oxide slowly and produces small solid residue granules in amongst the large solid residue granules. Both the small and large solid residue are removed in the ensuing sublimation step. There is no sublimation step between the two dry etch stages.

Abstract: A method of etching silicon-containing material is described and includes a SiConi™ etch having a greater or lesser flow ratio of hydrogen compared to fluorine than that found in the prior art. Modifying the flow rate ratios in this way has been found to reduce roughness of the post-etch surface and to reduce the difference in etch-rate between densely and sparsely patterned areas. Alternative means of reducing post-etch surface roughness include pulsing the flows of the precursors and/or the plasma power, maintaining a relatively high substrate temperature and performing the SiConi™ in multiple steps. Each of these approaches, either alone or in combination, serve to reduce the roughness of the etched surface by limiting solid residue grain size.

Abstract: Methods of dry etching silicon-containing dielectric films are described. The methods include maintaining a relatively high temperature of the dielectric films while etching in order to achieve reduced solid residue on the etched surface. Partially or completely avoiding the accumulation of solid residue increases the etch rate.

Abstract: A method of etching silicon oxide from a narrow trench and a wide trench (or open area) is described which allows the etch in the wide trench to progress further than the etch in the narrow trench. The method includes two dry etch cycles. The first dry etch cycle involves a low intensity or abbreviated sublimation step which leaves solid residue in the narrow trench. The remaining solid residue inhibits etch progress in the narrow trench during the second dry etch cycle allowing the etch in the wide trench to overtake the etch in the narrow trench.

Abstract: A method of etching silicon oxide from a multiple trenches is described which allows more homogeneous etch rates among trenches. The surfaces of the etched silicon oxide within the trench following the etch may also be smoother. The method includes two dry etch stages followed by a sublimation step. The first dry etch stage removes silicon oxide quickly and produces large solid residue granules. The second dry etch stage remove silicon oxide slowly and produces small solid residue granules in amongst the large solid residue granules. Both the small and large solid residue are removed in the ensuing sublimation step. There is no sublimation step between the two dry etch stages.

Abstract: Methods of dry etching silicon-containing dielectric films are described. The methods include maintaining a relatively high temperature of the dielectric films while etching in order to achieve reduced solid residue on the etched surface. Partially or completely avoiding the accumulation of solid residue increases the etch rate.

Abstract: A method of etching silicon oxide from a narrow trench and a wide trench (or open area) is described which allows the etch in the wide trench to progress further than the etch in the narrow trench. The method includes two dry etch cycles. The first dry etch cycle involves a low intensity or abbreviated sublimation step which leaves solid residue in the narrow trench. The remaining solid residue inhibits etch progress in the narrow trench during the second dry etch cycle allowing the etch in the wide trench to overtake the etch in the narrow trench.

Abstract: A method of etching silicon-containing material is described and includes a SiConi™ etch having a greater or lesser flow ratio of hydrogen compared to fluorine than that found in the prior art. Modifying the flow rate ratios in this way has been found to reduce roughness of the post-etch surface and to reduce the difference in etch-rate between densely and sparsely patterned areas. Alternative means of reducing post-etch surface roughness include pulsing the flows of the precursors and/or the plasma power, maintaining a relatively high substrate temperature and performing the SiConi™ in multiple steps. Each of these approaches, either alone or in combination, serve to reduce the roughness of the etched surface by limiting solid residue grain size.