Abstract: A method for fabricating a semiconductor device includes the steps of: forming a first inter-metal dielectric (IMD) layer on a substrate; forming a contact hole in the first IMD layer; forming a bottom electrode layer in the contact hole; forming a magnetic tunneling junction (MTJ) stack on the bottom electrode layer; and removing the MTJ stack and the bottom electrode layer to form a MTJ on a bottom electrode. Preferably, the bottom electrode protrudes above a top surface of the first IMD layer.

Abstract: A laser welding method for steel plates and a profile steel welded by laser welding are disclosed. The laser welding method comprises the following steps of connecting a first steel plate and a second steel plate to form a joint; and using a laser to weld the joint to form a profile steel. The laser has a laser power between 10,000 and 25,000 watts. A weld bead is formed at the joint. The weld bead has a weld depth and a weld width. The ratio of the weld depth to the weld width is between 1 and 5. Thus, the process can be simplified effectively, the welding time can be shortened, and the processing area can be reduced.

Abstract: A method includes forming a dielectric layer over an epitaxial source/drain region. An opening is formed in the dielectric layer. The opening exposes a portion of the epitaxial source/drain region. A barrier layer is formed on a sidewall and a bottom of the opening. An oxidation process is performing on the sidewall and the bottom of the opening. The oxidation process transforms a portion of the barrier layer into an oxidized barrier layer and transforms a portion of the dielectric layer adjacent to the oxidized barrier layer into a liner layer. The oxidized barrier layer is removed. The opening is filled with a conductive material in a bottom-up manner. The conductive material is in physical contact with the liner layer.

Abstract: A method of forming a semiconductor device includes: forming a via in a first dielectric layer disposed over a substrate; forming a second dielectric layer over the first dielectric layer; forming an opening in the second dielectric layer, where the opening exposes an upper surface of the via; selectively forming a capping layer over the upper surface of the via, where the capping layer has a curved upper surface that extends above a first upper surface of the first dielectric layer distal from the substrate; after forming the capping layer, forming a barrier layer in the opening over the capping layer and along sidewalls of the second dielectric layer exposed by the opening; and filling the opening by forming an electrically conductive material over the barrier layer.

Abstract: A method for fabricating semiconductor device includes the steps of first forming a gate structure on a substrate, forming a source/drain region adjacent to two sides of the gate structure, forming an epitaxial layer on the source/drain region, forming an interlayer dielectric (ILD) layer on the gate structure, forming a contact hole in the ILD layer to expose the epitaxial layer, forming a low stress metal layer in the contact hole, forming a barrier layer on the low stress metal layer, and forming an anneal process to form a first silicide layer and a second silicide layer.

Abstract: The invention provides a porous polyurethane polishing pad that includes a porous matrix. The matrix has large pores that extend upward from a base surface and open to an upper surface. The large pores are interconnected with tertiary pores, a portion of the large pores is open to a top polishing surface and at least a portion of the large pores extend to the top polishing surface. Spring-arm sections connect lower and upper sections of the large pores. The spring-arm sections all are in a same horizontal direction as measured from the vertical orientation and they combine for increasing compressibility of the polishing pad and contact area of the top polishing surface during polishing.

Abstract: The invention provides a method of forming porous polyurethane polishing pad that includes feeding liquid polyurethane onto a web sheet with a doctor blade while back tensioning the web. Coagulating liquid polyurethane onto the web sheet forms a two-layer substrate. The two-layer substrate has a porous matrix wherein the porous matrix has large pores extending upward from a base surface and open to an upper surface. Spring-arm sections connect lower and upper sections of the large pores.

Abstract: A process for chemical mechanical polishing a substrate containing tungsten and titanium is provided comprising: providing the substrate; providing a polishing composition, containing, as initial components: water; an oxidizing agent; a chitosan; a dicarboxylic acid, wherein the dicarboxylic acid is selected from the group consisting of propanedioic acid and 2-hydroxypropanedioic acid; a source of iron ions; a colloidal silica abrasive with a positive surface charge; and, optionally pH adjusting agent; providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein some of the tungsten (W) and some of the titanium (Ti) is polished away from the substrate with a removal selectivity for the tungsten (W) relative to the titanium (Ti).

Abstract: The invention provides a porous polyurethane polishing pad that includes a porous matrix. The matrix has large pores that extend upward from a base surface and open to an upper surface. The large pores are interconnected with tertiary pores, a portion of the large pores is open to a top polishing surface and at least a portion of the large pores extend to the top polishing surface. Spring-arm sections connect lower and upper sections of the large pores. The spring-arm sections all are in a same horizontal direction as measured from the vertical orientation and they combine for increasing compressibility of the polishing pad and contact area of the top polishing surface during polishing.

Abstract: The invention provides a porous polyurethane polishing pad that includes a porous matrix having large pores that extend upward from a base surface and open to an upper surface. The large pores extend to the top polishing surface and have lower and upper sections with a vertical orientation. The lower and upper sections are offset in a horizontal direction. Middle-sized pores with a columnar shape and a vertical orientation originate adjacent the middle sections and small pores with a columnar shape and a vertical orientation originate between the middle-sized pores. The pores combine for increasing compressibility of the polishing pad and contact area of the top polishing surface during polishing.

Abstract: The invention provides a method of forming porous polyurethane polishing pad that includes feeding liquid polyurethane onto a web sheet with a doctor blade while back tensioning the web. Coagulating liquid polyurethane onto the web sheet forms a two-layer substrate. The two-layer substrate has a porous matrix wherein the porous matrix has large pores extending upward from a base surface and open to an upper surface. Spring-arm sections connect lower and upper sections of the large pores.

Abstract: A process and composition are disclosed for polishing tungsten containing select quaternary phosphonium compounds at low concentrations to at least reduce corrosion rate of tungsten. The process and composition include providing a substrate containing tungsten; providing a stable polishing composition, containing, as initial components: water; an oxidizing agent; select quaternary phosphonium compounds at low concentrations to at least reduce corrosion rate; a dicarboxylic acid, a source of iron ions; a colloidal silica abrasive; and, optionally a pH adjusting agent; providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein some of the tungsten is polished away from the substrate, and corrosion rate of tungsten is reduced.

Abstract: A process for chemical mechanical polishing a substrate containing tungsten is disclosed to reduce corrosion rate and inhibit dishing of the tungsten and erosion of underlying dielectrics. The process includes providing a substrate; providing a polishing composition, containing, as initial components: water; an oxidizing agent; nonionic polyacrylamide; a dicarboxylic acid, a source of iron ions; a colloidal silica abrasive having a negative zeta potential; and, optionally, a pH adjusting agent; providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein some of the tungsten is polished away from the substrate, corrosion rate is reduced, dishing of the tungsten is inhibited as well as erosion of dielectrics underlying the tungsten.

Abstract: A process for chemical mechanical polishing a substrate containing tungsten is disclosed to reduce corrosion rate and inhibit dishing of the tungsten and erosion of underlying dielectrics. The process includes providing a substrate; providing a polishing composition, containing, as initial components: water; an oxidizing agent; nonionic polyacrylamide; a dicarboxylic acid, a source of iron ions; a colloidal silica abrasive having a negative zeta potential; and, optionally, a pH adjusting agent; providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein some of the tungsten is polished away from the substrate, corrosion rate is reduced, dishing of the tungsten is inhibited as well as erosion of dielectrics underlying the tungsten.

Abstract: A process and composition are disclosed for polishing tungsten containing select quaternary phosphonium compounds at low concentrations to at least reduce corrosion rate of tungsten. The process and composition include providing a substrate containing tungsten; providing a stable polishing composition, containing, as initial components: water; an oxidizing agent; select quaternary phosphonium compounds at low concentrations to at least reduce corrosion rate; a dicarboxylic acid, a source of iron ions; a colloidal silica abrasive; and, optionally a pH adjusting agent; providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein some of the tungsten is polished away from the substrate, and corrosion rate of tungsten is reduced.

Abstract: A process for chemical mechanical polishing a substrate containing tungsten is disclosed to reduce static corrosion rate and inhibit dishing of the tungsten and erosion of underlying dielectrics. The process includes providing a substrate; providing a polishing composition, containing, as initial components: water; an oxidizing agent; guar gum; a dicarboxylic acid, a source of iron ions; a colloidal silica abrasive; and, optionally a pH adjusting agent; providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein some of the tungsten (W) is polished away from the substrate, static corrosion rate is reduced, dishing of the tungsten (W) is inhibited as well as erosion of dielectrics underlying the tungsten (W).

Abstract: A process for chemical mechanical polishing a substrate containing tungsten to reduce static corrosion rate and inhibit dishing of the tungsten and erosion of underlying dielectrics is disclosed. The process includes providing a substrate; providing a polishing composition, containing, as initial components: water; an oxidizing agent; xanthan gum; a dicarboxylic acid, a source of iron ions; a colloidal silica abrasive; and, optionally a pH adjusting agent; optionally a surfactant; providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein some of the tungsten (W) is polished away from the substrate, static corrosion rate is reduced, dishing of the tungsten (W) is inhibited as well as erosion of dielectrics underlying the tungsten (W).

Abstract: A process for chemical mechanical polishing a substrate containing tungsten is disclosed to reduce static corrosion rate and inhibit dishing of the tungsten and erosion of underlying dielectrics. The process includes providing a substrate; providing a polishing composition, containing, as initial components: water; an oxidizing agent; alginate; a dicarboxylic acid, a source of iron ions; a colloidal silica abrasive; and, optionally a pH adjusting agent; providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein some of the tungsten (W) is polished away from the substrate, static corrosion rate is reduced, dishing of the tungsten (W) is inhibited as well as erosion of dielectrics underlying the tungsten (W).

Abstract: A process and composition are disclosed for polishing tungsten containing select quaternary phosphonium compounds at low concentrations to at least reduce corrosion rate of tungsten. The process and composition include providing a substrate containing tungsten; providing a stable polishing composition, containing, as initial components: water; an oxidizing agent; select quaternary phosphonium compounds at low concentrations to at least reduce corrosion rate; a dicarboxylic acid, a source of iron ions; a colloidal silica abrasive; and, optionally a pH adjusting agent; providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein some of the tungsten is polished away from the substrate, and corrosion rate of tungsten is reduced.

Abstract: A process for chemical mechanical polishing a substrate containing titanium nitride and titanium is provided comprising: providing a polishing composition, containing, as initial components: water; an oxidizing agent; a linear polyalkylenimine polymer; a colloidal silica abrasive with a positive surface charge; a carboxylic acid; a source of ferric ions; and, optionally pH adjusting agent; wherein the polishing composition has a pH of 1 to 4; providing a chemical mechanical polishing pad, having a polishing surface; creating dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein at least some of the titanium nitride and at least some of the titanium is polished away with a selectivity between titanium nitride and titanium.