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: 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: An emission site for a large area passive matrix cold cathode field emission display having an emission tip with a sharp profile is disclosed. A metallic film formed of iridium silicide (IrSi) is used to coat the tip. By using IrSi the tips of the emission sites can be formed at low temperatures. In addition, IrSi is a fine grain material that maintains a sharp profile and can be formed in a layer as thin as 100 Å.

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: 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: 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: 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 multilayer 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: An emission site for a large area passive matrix cold cathode field emission display having an emission tip with a sharp profile is disclosed. A metallic film formed of iridium silicide (IrSi) is used to coat the tip. By using IrSi the tips of the emission sites can be formed at low temperatures. In addition, IrSi is a fine grain material that maintains a sharp profile and can be formed in a layer as thin as 100 Å.

Abstract: A liner material and method of use is disclosed. The method includes depositing a silicon layer into a deep void, such as a via or trench, and physical vapor depositing a cobalt seed layer onto the silicon. A supplemental cobalt layer is electroplated over the seed layer. The structure is then annealed, forming cobalt silicide (CoSix). The layer can be made very thin, facilitating further filling the via with highly conductive metals. Advantageously, the layer is devoid of oxygen and nitrogen, and thus allows low temperature metal reflows in filling the via. The liner material has particular utility in a variety of integrated circuit metallization processes, such as damascene and dual damascene processes.

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: The invention includes methods of forming conductive lines, such as local interconnects. In one implementation, a method of forming a conductive line includes depositing a first layer comprising polymer silicon on a substrate. A metal layer is deposited at least over some portion of the first layer. After depositing the metal layer, the substrate is exposed to annealing conditions effective to form a metal silicide over the at least some portion. The metal silicide is provided into a desired conductive line shape. In one implementation, a method of forming a conductive line includes depositing a first layer comprising polymer silicon or amorphous silicon on a substrate. Only a portion of the first layer is exposed to both oxygen and ultraviolet light effective to transform at least an outer part of the portion to oxidized silicon.

Abstract: A liner material and method of use is disclosed. The method includes depositing a silicon layer into a deep void, such as a via or trench, and physical vapor depositing a cobalt seed layer onto the silicon. A supplemental cobalt layer is electroplated over the seed layer. The structure is then annealed, forming cobalt silicide (CoSix). The layer can be made very thin, facilitating further filling the via with highly conductive metals. Advantageously, the layer is devoid of oxygen and nitrogen, and thus allows low temperature metal reflows in filling the via. The liner material has particular utility in a variety of integrated circuit metallization processes, such as damascene and dual damascene processes.

Abstract: In a method of depositing polysilicon comprises providing a substrate within a chemical vapor deposition reactor, with the substrate having an exposed substantially crystalline region and an exposed substantially amorphous region. A gaseous precursor comprising silicon is fed to the chemical vapor deposition reactor under conditions effective to selectively deposit polysilicon on the crystalline region and not the amorphous region. In another aspect a method of fabricating a field effect transistor on a substrate comprises forming a gate dielectric layer and a gate over semiconductive material. A gaseous precursor comprising silicon is fed to the chemical vapor deposition reactor under conditions effective to substantially selectively deposit polysilicon on the source/drain regions and not on amorphous material, and forming elevated source/drains on the doped source/drain regions. In another aspect, a method of forming a contact to a substrate is disclosed.

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 (TiN.sub.x), 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: Conductive structures, conductive lines, conductive SRAM lines, integrated circuitry, SRAM cells, and methods of forming the same are described. In one embodiment, a substrate is provided and a layer comprising TiN is physical vapor deposited over the substrate having greater than or equal to about 90% by volume <200> grain orientation. In another embodiment, at least two components are electrically connected by forming a layer of TiN over a substrate having the desired by-volume concentration of <200> grain orientation, and etching the layer to form a conductive line. In a preferred embodiment, conductive lines formed in accordance with the invention electrically connect at least two SRAM components and preferably form cross-coupling electrical interconnections between first and second inverters of an SRAM cell.

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, H.sub.2 SO.sub.4, H.sub.3 PO.sub.4, HNO.sub.3, 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: Methods of establishing electrical communication with substrate node locations, methods of forming DRAM circuitry, and semiconductor assemblies are described. In one implementation, a contact opening is formed over a substrate node location with which electrical communication is desired. The contact opening has a base over which a refractory metal layer is formed. A refractory metal silicide layer is formed over the refractory metal layer, and the substrate is exposed to conditions effective to convert the refractory metal layer to a refractory metal silicide. In one embodiment, the refractory metal layer and the refractory metal silicide layer are chemical vapor deposited. In another embodiment, the refractory metal silicide layer comprises a silicide of the refractory metal layer. In a preferred implementation, the refractory metal layer comprises titanium and the refractory metal silicide layer comprises titanium silicide.