TWI258504B - Washing solution and washing method using the same - Google Patents

Abstract

This invention is to provide a washing liquid with excellent removal of impurities without corrosion of copper wiring used for semiconductor devices and the like or precipitation of the washing liquid components, particularly after chemical mechanical polishing (CMP) treatment using a slurry containing a highly adhesive anticorrosive agent such as benzotriazole without corrosion of copper wiring and capable of further removing benzotriazole together with impurity components under an alkaline condition. The washing liquid is composed of 0.001-60 wt.% of urea and/or ethyleneurea, 0.0001-10 wt.% of an alkaline component such as quaternary ammonium hydroxide and ammonia, 0.0001-10 wt.% of an organic acid such as citric acid, malic acid and tartaric acid or a salt thereof, 10 wt.% or less of hydrogen peroxide, if necessary, further a surfactant and water for the rest.

Description

(5) Specific examples of the organic acid of 1258504 include carboxylic acids such as formic acid, acetic acid, oxalic acid, malonic acid, succinic acid, and citric acid, citric acid, malic acid, tartaric acid, lactic acid, glycolic acid, salicylic acid, and the like. a sulfonic acid such as a hydroxycarboxylic acid, a methanesulfonic acid, an ethane acid extension, a P-toluenesulfonic acid or a 2,4-toluenedisulfonic acid; and the salt thereof may, for example, be a metal salt or ammonium such as a sodium salt or a potassium salt. Salt and so on. Among them, hydroxy carboxylic acid is preferred from the viewpoint of the ability to remove metal impurities and to prevent precipitation of crystallization of a urea-based compound, and citric acid, malic acid, and tartaric acid are preferred. These organic acids can also function to prevent the precipitation of urea compounds from the metal surface while removing metallic impurities. When the urea compound is used alone, the crystals on the surface of the metal are precipitated and it is difficult to remove only with water. The combination of the organic acids of the present invention prevents precipitation of crystals, and the effect of ethylene urea is particularly effective. These organic acids and/or salts thereof may be used singly or in combination of two or more kinds. These can generally be started by commercial products. The alkali component used in the cleaning liquid of the present invention can be used arbitrarily if it exhibits an alkalinity in an aqueous solution. However, semiconductor applications are preferred because they do not contain alkali metals such as Li, Na, K, etc. due to the abandonment of metal impurities. Specific examples include tetraammonium hydroxides such as tetramethylammonium hydroxide and trimethyl (hydroxy)ammonium hydroxide (commonly known as choline), and ammonia. Among them, it is particularly preferable to oxidize the fourth-stage saddle salt with ammonia or hydrogen depending on the washing performance, the inhibition of precipitation of urea and/or ethylene urea crystals, and the cost. On the one hand, when an amine such as methanolamine is used in combination with a urea compound, a urea compound is precipitated, resulting in unsatisfactory discoloration of copper. For the purpose of the present invention, hydrogen peroxide can be used as a strong film for removing benzotriazole or the like which is used as a resist, and it is difficult to remove the organic substance. The hydrogen peroxide used in the cleaning liquid of the present invention can be obtained by using the commercially available g (7) 1258504 pH of the cleaning liquid of the present invention, and the viewpoint of suppressing copper corrosion to obtain an excellent cleaning effect is 7 · 1 to 1 2 Ideally, it is more ideally 7.5~]1 · 5 , especially ideally 8 · 0~1丨.〇. The composition of the cleaning solution of the present invention can be adjusted to a specified pH by a combination of urea and/or ethylene urea, an organic acid and/or a salt thereof, and an alkaline component, hydrogen peroxide, and a surfactant, and the compounds thereof The mixing ratio varies depending on the compound to be used, and the content of urea and/or ethylene urea is 0.001 to 60% by weight, the content of the organic acid and/or its salt is ο·οοοι to 10% by weight, and the alkaline component The concentration is 0.000 1 to 1% by weight, the content of hydrogen peroxide is 3 〇% by weight or less, and the ideal content when using hydrogen peroxide is 0 · 0 1 to 30% by weight. When a surfactant is added, the content is 〇· 0 0 0 1~1 0% by weight is ideal (the rest is water, the total amount is 1% by weight). Outside this range, it is not unusable at the specified pH, which may result in reduced particle removal performance, copper corrosion, precipitation of urea or ethylene urea crystallization. In the cleaning solution of the present invention, each component may be added during washing, or the components may be mixed in advance and then used. The cleaning solution of the present invention can be used for cleaning of a copper wiring semiconductor device. When the cleaning liquid of the present invention is used, the absolute corrosion property to the copper wiring is small, and it is particularly suitable for cleaning after CMP. The washing means according to the present invention can be used without any particular limitation, and can be washed with running water, washed with immersion, washed with shaking, washed with spin, washed with a stir bar, washed with a spray, washed with an ultrasonic wave, washed with a brush, or washed with a brush. A well-known means. The temperature at the time of washing -11 - (8) 1258504 degrees is not particularly limited, and is preferably 0 to 1 0 0 t depending on corrosion inhibition, particle removal property, and workability. [Effect of the Invention] The cleaning liquid of the present invention exhibits no detergent liquid precipitation component when the impurities of the excellent cleaning ability are removed, and can be used as a cleaning liquid which does not corrode copper, and the copper surface can be attached when hydrogen peroxide is added. The benzotriazole machine is removed and is highly suitable for use as a semiconductor device. [Embodiment] Hereinafter, the method of the present invention will be described by way of examples, and the present invention is not limited to the embodiment. Examples 1 to 8 and Comparative Examples 1 to 4 (particle removal property)

The copper-plated wafer was immersed in ultrapure water having a dispersed average particle diameter of 1 20 nm, and then ultrafine water adjusted to pH 6 with sulfuric acid, and dried as particles contaminated with cerium oxide particles. The wafer was washed with a surface cleaning solution at 50 ° C for 3 minutes in a dipping bath, washed with water and then dried to observe the number of cerium oxide particles per unit by S EM (scanning electron microscopy). The SEM was measured using JSM particle removability by JEOL Ltd. according to the following criteria. 〇: the view of good removability, the same, and so on, etc.

Oxidize and wash. 1 shows dry. Table area T22 0A ^ 12-

Claims (1)

1258504 (1) Picking up, applying for patent coverage No. 92 1 36253 Patent application Chinese patent application scope revision Amendment of April 6, 1995 of the Republic of China 1. A cleaning liquid characterized by (1) water content, (2) Urea and / or ethylene urea, (3) organic acids and / or their salts, and (4) alkaline components 〇 2 · A cleaning solution according to item 1 of the patent application, wherein the alkaline component is ammonia and/or ammonium hydroxide. 3 · The washing liquid according to item 1 of the patent application, wherein one or more organic acids and salts thereof are selected from the group consisting of oxalic acid, malonic acid, malic acid, citric acid, succinic acid, citric acid, tartaric acid, lactic acid, glycolic acid and The salt of these is a group of people. 4. If the cleaning solution of the first application of the patent scope is contained, it further contains hydrogen peroxide. 5 · If the cleaning solution of the first application of the patent scope, the surfactant is further included. 6 · A cleaning solution according to item 5 of the patent application, wherein the surfactant is a nonionic surfactant. 7. The cleaning solution according to claim 5, wherein at least one of the surfactants is selected from the group consisting of ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol propyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, Propylene glycol diethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol diethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, dipropylene glycol methyl ether, dipropylene glycol ether, dipropylene 1258504 (2) A group of alcoholic propyl ethers and dipropylene glycol butyl ethers. 8 · As in the scope of the patent scope of the cleaning solution, wherein the pH of the cleaning solution is 7 · 1~1 2 . 9. The cleaning solution according to any one of claims 1 to 8, wherein the concentration of urea and/or ethylene urea is 0.001 to 60% by weight, and the concentration of the organic acid is 0. 0 0 0 1~1 The weight % of cerium, the concentration of the alkaline component is 0.000 1 to 10% by weight, the content of hydrogen peroxide is 30% by weight or less, and the surfactant is 10% by weight or less. The cleaning solution according to any one of claims 1 to 8, which is used for cleaning a semiconductor device. 1 1 The washing liquid according to any one of the above claims, which is used for cleaning a semiconductor device having copper wiring.