Liquid composition for removing titanium nitride, semiconductor-element cleaning method using same, and semiconductor-element manufacturing method

Abstract

This invention provides a liquid composition that removes titanium nitride from a substrate without corroding tungsten or a low-k interlayer dielectric also present on said substrate. Said liquid composition has a pH between 0 and 4, inclusive, and contains the following: at least one oxidizing agent (A) selected from the group consisting of potassium permanganate, ammonium peroxodisulfate, potassium peroxodisulfate, and sodium peroxodisulfate; a fluorine compound (B); and a tungsten-corrosion preventer (C). The tungsten-corrosion preventer (C) either contains at least two different compounds selected from a group of compounds (C1) consisting of alkylamines, salts thereof, fluoroalkylamines, salts thereof, and the like or contains at least one compound selected from said group of compounds (C1) and at least one compound selected from a group of compounds (C2) consisting of polyoxyalkylene alkylamines, polyoxyalkylene fluoroalkylamines, and the like. The mass concentration of potassium permanganate in the abovementioned oxidizing agent (A) is between 0.001% and 0.1%, inclusive, and the mass concentration of the abovementioned fluorine compound (B) is between 0.01% and 1%, inclusive.