Abstract: The present invention relates to a method of selectively removing metal oxide, particularly tungsten oxide without etching the un-oxidized metal. The method removes metal oxide with little or no loss of the clean metal to improve the contact resistance for contact metal in semiconductor device fabrication. The method includes a step of exposing a substrate containing a tungsten oxide layer over a tungsten layer to a low oxygen aqueous ammonia solution to selectively remove the tungsten oxide layer. The low oxygen aqueous ammonia solution has an ammonia concentration in a range of about 0.01 M to about 2.0 M. The oxygen level in the solution is no more than 50 ppb. The solution may further contain a corrosion inhibitor and/or a compound having two or more carboxyl groups separated by at least one carbon atom.

Abstract: An etching method. The method includes etching a first plurality of silicon wafers in a first enchant, each silicon wafer having SiO2 and Si3N4 deposited thereon, where the etching includes dissolving a quantity of the SiO2 and a quantity of the Si3N4 in the first etchant. A quantity of insoluble SiO2 precipitates. A ratio of a first etch rate of Si3N4 to a first etch rate of SiO2 is determined to be less than a predetermined threshold. A portion of the first etchant is combined with a second etchant to form a conditioned etchant. A second plurality of silicon wafers is etched in the conditioned etchant. A ratio of a second etch rate of Si3N4 to a second etch rate of SiO2 in the conditioned etchant is greater than the threshold. A method for exchanging an etching bath solution and a method for forming a selective etchant are also disclosed.

Abstract: An etching method. The method includes etching a first plurality of silicon wafers in a first enchant, each silicon wafer having SiO2 and Si3N4 deposited thereon, where the etching includes dissolving a quantity of the SiO2 and a quantity of the Si3N4 in the first etchant. A quantity of insoluble SiO2 precipitates. A ratio of a first etch rate of Si3N4 to a first etch rate of SiO2 is determined to be less than a predetermined threshold. A portion of the first etchant is combined with a second etchant to form a conditioned etchant. A second plurality of silicon wafers is etched in the conditioned etchant. A ratio of a second etch rate of Si3N4 to a second etch rate of SiO2 in the conditioned etchant is greater than the threshold. A method for exchanging an etching bath solution and a method for forming a selective etchant are also disclosed.

Abstract: An etching method. The method includes etching a first plurality of silicon wafers in a first enchant, each silicon wafer having SiO2 and Si3N4 deposited thereon, where the etching includes dissolving a quantity of the SiO2 and a quantity of the Si3N4 in the first echant. A quantity of insoluble SiO2 precipitates. A ratio of a first etch rate of Si3N4 to a first etch rate of SiO2 is determined to be less than a predetermined threshold. A portion of the first etchant is combined with a second etchant to form a conditioned etchant. A second plurality of silicon wafers is etched in the conditioned etchant. A ratio of a second etch rate of Si3N4 to a second etch rate of SiO2 in the conditioned etchant is greater than the threshold. A method for exchanging an etching bath solution and a method for forming a selective etchant are also disclosed.

Abstract: A method of batching substrates in an automated processing tool, the automated process tool and a system for batching substrates in the automated process tool. The method includes selecting a first container containing a first group of substrates; simultaneously transferring each substrate of the first group of substrates into a batching station of the automated processing tool; selecting a second container containing a second group of substrates; selecting less than all substrates of the second group of substrates; and transferring each substrate of the less than all substrates of the second group of substrates to the batching station to form a third group of substrates.

Abstract: An etching method. The method includes etching a first plurality of silicon wafers in a first enchant, each silicon wafer having SiO2 and Si3N4 deposited thereon, where the etching includes dissolving a quantity of the SiO2 and a quantity of the Si3N4 in the first echant. A quantity of insoluble SiO2 precipitates. A ratio of a first etch rate of Si3N4 to a first etch rate of SiO2 is determined to be less than a predetermined threshold. A portion of the first etchant is combined with a second etchant to form a conditioned etchant. A second plurality of silicon wafers is etched in the conditioned etchant. A ratio of a second etch rate of Si3N4 to a second etch rate of SiO2 in the conditioned etchant is greater than the threshold. A method for exchanging an etching bath solution and a method for forming a selective etchant are also disclosed.

Abstract: A method of batching substrates in an automated processing tool, the automated process tool and a system for batching substrates in the automated process tool. The method includes selecting a first container containing a first group of substrates; simultaneously transferring each substrate of the first group of substrates into a batching station of the automated processing tool; selecting a second container containing a second group of substrates; selecting less than all substrates of the second group of substrates; and transferring each substrate of the less than all substrates of the second group of substrates to the batching station to form a third group of substrates.