Alkaline aqueous solution composition for treating a substrate

Abstract

An aqueous solution of ammonia, tetramethylammonium hydroxide and sodium hydroxide, etc. has been used as a cleaning liquid and an etching liquid of a semiconductor substrate and a glass substrate. However, the metal impurities in the alkali components are adsorbed onto the substrate surface during treatment, so that a process for removing the adsorbed metal impurities is necessary as the next process. In addition, in the case of the cleaning liquid, though it is effective in the removal of fine particles, the metal impurities cannot be cleaned, so that it is necessary to carry out acid cleaning, which makes the process complicated. According to the present invention, the alkaline aqueous solution for treating a substrate wherein an alkali component and a specific chelating agent are combined prevents adsorption of metal impurities onto the substrate, and further cleans and removes the metals adhered to the substrate. If necessary, it is also possible to add a metal anticorrosive and a surfactant to suppress corrosion of the metal materials, or enhance affinity to the substrate and ability for removing fine particles.

Description

technical field The present invention relates to a substrate treatment alkaline aqueous solution composition used for etching or cleaning a substrate. More specifically, it relates to an etching process or a cleaning process using an alkaline aqueous solution, which is used to prevent the The metal impurities adhere to the surface of the substrate and are further cleaned and removed with an alkaline aqueous solution composition for substrate treatment. Background technique In the manufacturing process of silicon wafers for semiconductor manufacturing, when wafers are diced from silicon single crystal ingots and processed to a predetermined thickness, etching is performed with an alkali such as sodium hydroxide or potassium hydroxide in order to achieve uniform etching. At this time, a large amount of metal impurities in sodium hydroxide or potassium hydroxide will be adsorbed on the wafer surface. Usually after etching, it is removed by cleaning with an acid such as dilute...

AI Technical Summary

Problems solved by technology

Usually after etching, it is removed by cleaning with an acid such as dilute hydrofluoric acid, but especially in low-resistance substrates with a high concentration of boron and the like, Cu and Ni are easy to diffuse inside, and Ni in sodium hydroxide or hydroxide Potassium is used at a temperature of around 80°C to cause diffusion, so surface cleaning with acid cannot remove internally diffused metal impurities, which has become a problem

In addition, in addition to Cu and Ni, a large amount of transition metals such as Fe are actually adsorbed on the surface of the silicon wafer, and it is necessary to remove them by cleaning with an acidic cleaning solution. decreased throughput, etc.

This cleaning process accounts for about 1 / 3 of the semiconductor manufacturing process. If two types of liquids, alkaline cleaning liquid and acidic cleaning liquid, are used for the entire process, the following problems will arise: the semiconductor manufacturing process will become longer and more complicated, and the cost will increase. drop etc.

However, these chelating agents or complexing agents are all used in the cleaning solution SC-1, which is a mixture of ammonia and hydrogen peroxide, which is a representative cleaning solution used in semiconductor processes. It is also effective, but it is difficult to form a stable complex in a strong alkaline aqueous solution such as sodium hydroxide or tetramethylammonium hydroxide, and there is no sufficient effect

Therefore, there is no substrate containing strong alkali components such as sodium hydroxide or tetramethylammonium hydroxide that can effectively prevent the metal impurities in the alkali component from being adsorbed on the substrate and can effectively clean and remove the metal adsorbed on the substrate. Etching and cleaning solutions for processing