Abstract: Etching of nitride and oxide layers with reactant gases is modulated by etching in different process regimes. High etch selectivity to silicon nitride is achieved in an adsorption regime where the partial pressure of the etchant is lower than its vapor pressure. Low etch selectivity to silicon nitride is achieved in a condensation regime where the partial pressure of the etchant is higher than its vapor pressure. By controlling partial pressure of the etchant, very high etch selectivity to silicon nitride may be achieved.

Abstract: Etching of nitride and oxide layers with reactant gases is modulated by etching in different process regimes. High etch selectivity to silicon nitride is achieved in an adsorption regime where the partial pressure of the etchant is lower than its vapor pressure. Low etch selectivity to silicon nitride is achieved in a condensation regime where the partial pressure of the etchant is higher than its vapor pressure. By controlling partial pressure of the etchant, very high etch selectivity to silicon nitride may be achieved.

Abstract: Methods for accurate and conformal removal of atomic layers of materials make use of the self-limiting nature of adsorption of at least one reactant on the substrate surface. In certain embodiments, a first reactant is introduced to the substrate in step (a) and is adsorbed on the substrate surface until the surface is partially or fully saturated. A second reactant is then added in step (b), reacting with the adsorbed layer of the first reactant to form an etchant. The amount of an etchant, and, consequently, the amount of etched material is limited by the amount of adsorbed first reactant. By repeating steps (a) and (b), controlled atomic-scale etching of material is achieved. These methods may be used in interconnect pre-clean applications, gate dielectric processing, manufacturing of memory devices, or any other applications where removal of one or multiple atomic layers of material is desired.

Abstract: Methods for removing silicon nitride and elemental silicon during contact preclean process involve converting these materials to materials that are more readily etched by fluoride-based etching methods, and subsequently removing the converted materials by a fluoride-based etch. Specifically, silicon nitride and elemental silicon may be treated with an oxidizing agent, e.g., with an oxygen-containing gas in a plasma, or with O2 or O3 in the absence of plasma to produce a material that is more rich in Si—O bonds and is more easily etched with a fluoride-based etch. Alternatively, silicon nitride or elemental silicon may be doped with a number of doping elements, e.g., hydrogen, to form materials which are more easily etched by fluoride based etches. The methods are particularly useful for pre-cleaning contact vias residing in a layer of silicon oxide based material because they minimize the unwanted increase of critical dimension of contact vias.

Abstract: Methods for accurate and conformal removal of atomic layers of materials make use of the self-limiting nature of adsorption of at least one reactant on the substrate surface. In certain embodiments, a first reactant is introduced to the substrate in step (a) and is adsorbed on the substrate surface until the surface is partially or fully saturated. A second reactant is then added in step (b), reacting with the adsorbed layer of the first reactant to form an etchant. The amount of an etchant, and, consequently, the amount of etched material is limited by the amount of adsorbed first reactant. By repeating steps (a) and (b), controlled atomic-scale etching of material is achieved. These methods may be used in interconnect pre-clean applications, gate dielectric processing, manufacturing of memory devices, or any other applications where removal of one or multiple atomic layers of material is desired.

Abstract: A multi-stage precursor vessel system for an atomic layer deposition (ALD) system in which a precursor is transferred from a first, low temperature reservoir chamber into a second (or subsequent) chamber at higher temperature, which second (or subsequent) chamber is used to create a highest possible vapor pressure of the precursor allowed by its temperature without decomposition in the timeframe of its residence therein.

Abstract: Different periods of an ALD cycle are performed using different purge flows and, in some cases, different pumping capacities, while maintaining the reactor chamber at a nominally constant pressure. The purge flows may, in some cases, utilize different gasses and/or may be provided through different flow paths. These operations provide for ALD cycle time improvements and economical operation with respect to consumables usage. In some embodiments the use of an annular throttle valve provides a means for controlling downstream flow limiting conductances in a gas flow path from the reactor chamber.

Abstract: An aluminum oxide film is deposited on a heated substrate by CVD from one or more alkylaluminum alkoxide compounds having composition R.sub.n Al.sub.2 (OR').sub.6-n, wherein R and R' are alkyl groups and n is in the range of 1 to 5.