Method for cleaning chip surface after polishing aluminum wire in super large scale integrated circuit

Abstract

The invention relates to a method for cleaning a chip surface after polishing an aluminum wire in a super large scale integrated circuit, which is characterized by comprising the following steps of: preparing a water polishing liquid; weighing deionized water in weight percentage, adding 0.5-5% of surfactant, 0.1-5% of FA / O chelant type II and 0.01-5% of FA / O rust inhibitor type II while uniformly stirring, and preparing into a neutral water polishing liquid after uniform stirring; and after the chemical mechanical polishing (CMP) of the aluminum wire, immediately polishing the workpiece by using the neutral water polishing liquid in a high flow method so as to clean the surface. The invention has the advantage that water polishing is used before a polishing disk stops rotating after CMP, high flow water polishing is used to clean the chip surface, and no corrosion on equipment is produced; non-uniformly distributed polishing liquid and large particles remaining on the chip surface can be washed away quickly, so that a clean and perfect polishing surface can be obtained.

Description

technical field

[0001] The invention belongs to the polishing technology, in particular to a method for cleaning the surface of a wafer after the aluminum wiring of a VLSI is polished. Background technique

[0002] At present, the most widely used integrated circuits are still products above 90 nanometers, and the wiring metal is aluminum. The chemical mechanical polishing (CMP) process is a very important link in the multilayer wiring process of VLSI. The surface flatness, roughness and surface sticking of ULSI multilayer aluminum wiring after chemical mechanical polishing (CMP) directly affect the The wiring of the next layer of aluminum affects the breakdown characteristics, interface state and minority carrier lifetime of the circuit, which is directly related to the performance quality and yield of IC devices. During the CMP process, a large amount of organic matter, particles, and especially heavy metal ions are introduced. Because metal aluminum is relatively active...