Abstract: Metal nitride and metal oxynitride extrusions often form on metal suicides. These extrusions can cause short circuits and degrade processing yields. The present invention discloses a method of selectively removing such extrusions. In one embodiment, a novel wet etch comprising an oxidizing agent and a chelating agent selectively removes the extrusions from a wordline in a memory array. In another embodiment, the wet etch includes a base that adjusts the pH of the etch to selectively remove certain extrusions relative to other substances in the wordline. Accordingly, new metal silicide structures can be used to form novel wordlines and other types of integrated circuits.

Abstract: Various embodiments of the invention described herein reduce contact resistance to a silicon-containing material using a first refractory metal material overlying the silicon-containing material and a second refractory metal material overlying the first refractory metal material. Each refractory metal material is a conductive material containing a refractory metal and an impurity. The first refractory metal material is a metal-rich material, containing a level of its impurity at less than a stoichiometric level. The second refractory metal material has a lower affinity for the impurities than does the first refractory metal material. The second refractory metal material can thus serve as an impurity donor during an anneal or other exposure to heat.

Abstract: Metal nitride and metal oxynitride extrusions often form on metal silicides. These extrusions can cause short circuits and degrade processing yields. The present invention discloses a method of selectively removing such extrusions. In one embodiment, a novel wet etch comprising an oxidizing agent and a chelating agent selectively removes the extrusions from a wordline in a memory array. In another embodiment, the wet etch includes a base that adjusts the pH of the etch to selectively remove certain extrusions relative to other substances in the wordline. Accordingly, new metal silicide structures can be used to form novel wordlines and other types of integrated circuits.

Abstract: Metal nitride and metal oxynitride extrusions often form on metal silicides. These extrusions can cause short circuits and degrade processing yields. The present invention discloses a method of selectively removing such extrusions. In one embodiment, a novel wet etch comprising an oxidizing agent and a chelating agent selectively removes the extrusions from a wordline in a memory array. In another embodiment, the wet etch includes a base that adjusts the pH of the etch to selectively remove certain extrusions relative to other substances in the wordline. Accordingly, new metal silicide structures can be used to form novel wordlines and other types of integrated circuits.

Abstract: A conductive structure for use in a semiconductor device includes a multilayer structure. A first layer includes a material containing silicon, e.g., polysilicon and silicon germanide. A barrier layer is formed over the first layer, with the barrier layer including metal silicide or metal silicide nitride. A top conductive layer is formed over the barrier layer. The top conductive layer can include metal or metal silicide. Selective oxidation can be performed to reduce the amount of oxidation of selected materials in a structure containing multiple layers, such as the multi-layer conductive structure. The selective oxidation is performed in a single-wafer rapid thermal processing system, in which a selected ambient, including hydrogen, is used to ensure low oxidation of a selected material, such as tungsten or a metal nitride.

Abstract: Metal nitride and metal oxynitride extrusions often form on metal silicides. These extrusions can cause short circuits and degrade processing yields. The present invention discloses a method of selectively removing such extrusions. In one embodiment, a novel wet etch comprising an oxidizing agent and a chelating agent selectively removes the extrusions from a wordline in a memory array. In another embodiment, the wet etch includes a base that adjusts the pH of the etch to selectively remove certain extrusions relative to other substances in the wordline. Accordingly new metal silicide structures can be used to form novel wordlines and other types of integrated circuits.

Abstract: The invention includes a method of forming a semiconductor construction. A metal-rich metal silicide layer is formed on a silicon-comprising substrate, and a metal nitride layer is formed on the metal-rich metal silicide layer. The metal-rich metal silicide layer and metal nitride layer are thermally processed to convert some of the metal-rich metal silicide into a stoichiometric metal silicide region. The thermal processing also drives nitrogen from the metal nitride layer into the metal-rich metal silicide layer to convert some of the metal-rich metal silicide layer into a region comprising metal, silicon and nitrogen. The invention also includes semiconductor constructions comprising a layer of MSi2 and a layer of MSiqNr, where M is Ta, W or Mo, and both q and r are greater than 0 and less than 2.

Abstract: The invention includes buried bit line memory circuitry, methods of forming buried bit line memory circuitry, and semiconductor processing methods of forming conductive lines. In but one implementation, a semiconductor processing method of forming a conductive line includes forming a silicon comprising region over a substrate. A TiNx comprising layer is deposited over the silicon comprising region, where “x” is greater than 0 and less than 1. The TiNx comprising layer is annealed in a nitrogen containing atmosphere effective to transform at least an outermost portion of the TiNx layer over the silicon comprising region to TiN. After the annealing, an elemental tungsten comprising layer is deposited on the TiN and at least the elemental tungsten comprising layer, the TiN, and any remaining TiNx layer is patterned into conductive line. In one implementation, a method such as the above is utilized in the fabrication of buried bit line memory circuitry.

Abstract: Disclosed are structures and processes which are related to asymmetric, self-aligned silicidation in the fabrication of integrated circuits. A pre-anneal contact stack includes a silicon substrate, a metal source layer such as titanium-rich titanium nitride (TiNx), and a silicon layer. The metal nitride layer is deposited on the substrate by sputtering a target metal reactively in nitrogen and argon ambient. A N:Ar ratio is selected to deposit a uniform distribution of the metal nitride in an unsaturated mode (x<1) over the silicon substrate. The intermediate substrate structure is sintered to form a metal silicide. The silicidation of metal asymmetrically consumes less of the underlying silicon than the overlying silicon layer. The resulting structure is a mixed metal silicide/nitride layer which has a sufficient thickness to provide low sheet resistance without excessively consuming the underlying substrate.

Abstract: A polycide structure for use in an integrated circuit comprises a silicon layer; a barrier layer comprising ZSix where x is greater than two and Z is chosen from the group consisting of tungsten, tantalum and molybdenum; and a metal silicide layer, preferably cobalt silicide. The structure is particularly useful in applications requiring high temperature processing. The structure may be used as a gate stack, especially in memory applications such as DRAM. The structure provides thermal stability, thus avoiding agglomeration problems associated with high temperature processing combined with low resistivity.

Abstract: A method of forming a catalyst body by forming a first layer of hemispherical grain polysilicon over a substrate, and oxidizing at least a portion of the first layer to form a second layer of silica. Additionally, forming a third layer of nitride material over the second layer, and forming a catalyst material over the nitride layer, can be performed before annealing to form a catalyst body.

Abstract: A method of preventing formation of titanium oxide within a semiconductor device structure during a high temperature treatment of the device structure includes forming a passivation layer to preclude formation of titanium oxide at a titanium/oxide interface of a semiconductor device structure. The method includes providing a substrate assembly including at least an oxide region and forming a layer of titanium over a surface of the oxide region. The oxide region surface is treated with a plasma comprising nitrogen prior to forming the titanium layer so as to form a passivation layer upon which the titanium layer is formed. A thermal treatment is performed on the substrate assembly with the passivation layer substantially inhibiting diffusion of oxygen from the oxide layer during the thermal treatment of the substrate assembly. Generally, the passivation layer comprises SixOyNz.

Abstract: A method of preventing formation of titanium oxide within a semiconductor device structure during a high temperature treatment of the device structure includes forming a passivation layer to preclude formation of titanium oxide at a titanium/oxide interface of a semiconductor device structure. The method includes providing a substrate assembly including at least an oxide region and forming a layer of titanium over a surface of the oxide region. The oxide region surface is treated with a plasma comprising nitrogen prior to forming the titanium layer so as to form a passivation layer upon which the titanium layer is formed. A thermal treatment is performed on the substrate assembly with the passivation layer substantially inhibiting diffusion of oxygen from the oxide layer during the thermal treatment of the substrate assembly. Generally, the passivation layer comprises SixOyNz.

Abstract: An etching method for use in integrated circuit fabrication includes providing a metal nitride layer on a substrate assembly, providing regions of cobalt silicide on first portions of the metal nitride layer, and providing regions of cobalt on second portions of the metal nitride layer. The regions of cobalt and the second portions of the metal nitride layer are removed with at least one solution including a mineral acid and a peroxide. The mineral acid may be selected from the group including HCl, H2SO4, H3PO4, HNO3, and dilute HF preferably the mineral acid is HCl) and the peroxide may be hydrogen peroxide. Further, the removal of the regions of cobalt and the second portions of the metal nitride layer may include a one step process or a two step process. In the one step process, the regions of cobalt and the second portions of the metal nitride layer are removed with a single solution including the mineral acid and the peroxide.

Abstract: Metal nitride and metal oxynitride extrusions often form on metal silicides. These extrusions can cause short circuits and degrade processing yields. The present invention discloses a method of selectively removing such extrusions. In one embodiment, a novel wet etch comprising an oxidizing agent and a chelating agent selectively removes the extrusions from a wordline in a memory array. In another embodiment, the wet etch includes a base that adjusts the pH of the etch to selectively remove certain extrusions relative to other substances in the wordline. Accordingly, new metal silicide structures can be used to form novel wordlines and other types of integrated circuits.

Abstract: A method of preventing formation of titanium oxide within a semiconductor device structure during a high temperature treatment of the device structure includes forming a passivation layer to preclude formation of titanium oxide at a titanium/oxide interface of a semiconductor device structure. The method includes providing a substrate assembly including at least an oxide region and forming a layer of titanium over a surface of the oxide region. The oxide region surface is treated with a plasma comprising nitrogen prior to forming the titanium layer so as to form a passivation layer upon which the titanium layer is formed. A thermal treatment is performed on the substrate assembly with the passivation layer substantially inhibiting diffusion of oxygen from the oxide layer during the thermal treatment of the substrate assembly. Generally, the passivation layer comprises SixOyNz.

Abstract: The invention includes a method of forming a semiconductor construction. A metal-rich metal suicide layer is formed on a silicon-comprising substrate, and a metal nitride layer is formed on the metal-rich metal silicide layer. The metal-rich metal silicide layer and metal nitride layer are thermally processed to convert some of the metal-rich metal silicide into a stoichiometric metal silicide region. The thermal processing also drives nitrogen from the metal nitride layer into the metal-rich metal silicide layer to convert some of the metal-rich metal silicide layer into a region comprising metal, silicon and nitrogen. The invention also includes semiconductor constructions comprising a layer of MSi2 and a layer of MSiqNr, where M is Ta, W or Mo, and both q and r are greater than 0 and less than 2.

Abstract: Disclosed are structures and processes which are related to asymmetric, self-aligned silicidation in the fabrication of integrated circuits. A pre-anneal contact stack includes a silicon substrate, a metal source layer such as titanium-rich titanium nitride (TiNx), and a silicon layer. The metal nitride layer is deposited on the substrate by sputtering a target metal reactively in nitrogen and argon ambient. A N:Ar ratio is selected to deposit a uniform distribution of the metal nitride in an unsaturated mode (x<1) over the silicon substrate. The intermediate substrate structure is sintered to form a metal silicide. The silicidation of metal asymmetrically consumes less of the underlying silicon than the overlying silicon layer. The resulting structure is a mixed metal silicide/nitride layer which has a sufficient thickness to provide low sheet resistance without excessively consuming the underlying substrate.

Abstract: The invention encompasses methods of forming silicide interconnects over silicon comprising substrates. In one implementation, a first layer comprising a metal and a non-metal impurity is formed over a region of a silicon comprising substrate where a silicide interconnection is desired. An elemental metal comprising second layer is formed over the first layer. The substrate is annealed to cause a reaction between at least the elemental metal of the second layer and silicon of the substrate region to form a silicide of the elemental metal of the second layer. In another considered aspect, a method of forming a silicide interconnect over a silicon comprising substrate includes providing a buffering layer to silicon diffusion between a refractory metal comprising layer and a silicon containing region of a substrate.

Abstract: The invention includes a method of forming a semiconductor construction. A metal-rich metal silicide layer is formed on a silicon-comprising substrate, and a metal nitride layer is formed on the metal-rich metal silicide layer. The metal-rich metal silicide layer and metal nitride layer are thermally processed to convert some of the metal-rich metal silicide into a stoichiometric metal silicide region. The thermal processing also drives nitrogen from the metal nitride layer into the metal-rich metal silicide layer to convert some of the metal-rich metal silicide layer into a region comprising metal, silicon and nitrogen. The invention also includes semiconductor constructions comprising a layer of MSi2 and a layer of MSiqNr, where M is Ta, W or Mo, and both q and r are greater than 0 and less than 2.