WO2006122491A1

WO2006122491A1 - Polishing slurry

Info

Publication number: WO2006122491A1
Application number: PCT/CN2006/000973
Authority: WO
Inventors: Danny Zhenglong Shiao; Andy Chunxiao Yang
Original assignee: Anji Microelectronics (Shanghai) Co., Ltd
Priority date: 2005-05-17
Filing date: 2006-05-15
Publication date: 2006-11-23
Also published as: CN1865385B; CN1865385A

Abstract

The present invention discloses a polishing slurry, wherein, the said polishing slurry contains polishing abrasive grains and a carrier, it further contains a reagent which has two functional groups. The polishing slurry of the present invention can reduce the concentration of the abrasive grains in the polishing slurry and lessen the downwards polishing pressure required in a CMP process, thereby it can improve the quality of the substrate and minimize the rate of defect, at the same time it can keep the desired polishing rate.

Description

Polishing slurry

Technical field

The invention relates to a polishing paddle. technical background

With the development of microelectronics technology, the integration of very large-scale integrated circuit chips has reached several billion components, and the feature size has entered the nanometer level. This requires nearly one hundred processes in the microelectronics process, especially multilayer wiring and lining. The bottom and the medium must be chemically mechanically planarized, while chemical mechanical polishing

(CMP) has proven to be the best method of planarization.

In a typical chemical mechanical polishing process, the substrate is placed in direct contact with a rotating polishing pad and a load is applied to the back side of the substrate with a load. During polishing, the gasket and the table rotate while maintaining a downward force on the back side of the substrate, applying an abrasive and a chemically active solution (commonly referred to as a slurry) to the gasket, which occurs with the film being polished. The chemical reaction begins the polishing process.

In the CMP process, reducing defects and controlling corrosion are two key performance criteria, so the surface of the substrate needs to be protected when forming a surface film. If the film is too weak, the protection has no effect; if the film is too hard, it is difficult to remove. For example, benzotriazole (BTA), triazole, etc. have been used as film formers or corrosion inhibitors in chemical mechanical polishing processes, whereas BTA typically forms a dense and strong film with Cu. The film is too strong, the polishing rate is reduced, and the mechanical action needs to be strengthened, and the strong mechanical action causes scratch problems and other defects.

With the introduction of insulating materials with a low dielectric constant k into the chip, there is an urgent need to improve the conventional CMP process. Because most materials with a low dielectric constant k are extremely fragile. In the CMP process, it is desirable to reduce the concentration of abrasive particles and reduce the downward pressure to eliminate defects or reduce them to Minimize while maintaining a high removal rate. Summary of invention

It is an object of the invention to provide a polishing slurry.

The above object of the present invention is achieved by the following technical solution: the polishing slurry comprises abrasive particles and a carrier, which further comprises a bifunctional reagent, preferably water.

Wherein, the bifunctional reagent is XRY; wherein X is a hydrophilic group, Y is a group capable of bonding to a surface of a metal substrate, and R is a fluorenylene group of QrC ₆ or an arylene group of C ₆ , preferably C An alkylene group of _r C ₄ . X is preferably a hydroxyl group, a carboxyl group, a sulfate group, a sulfonic acid group or a phosphoric acid group; Y is preferably an amino group, a triazolyl group, an imidazolyl group or an ammonium group. A functional group on the bifunctional reagent interacts with the polishing substrate to form a protective film on the surface of the substrate, and another functional group (such as: -OH, -COOH, -S0 ₃ H, etc.) has an affinity with the abrasive particles and assists The abrasive particles remove the film, thereby reducing the concentration of the abrasive particles and the downward force during polishing.

The polishing slurry also includes an oxidizing agent, a complexing agent, and/or a surfactant.

The concentration of the abrasive particles is 1-30%, the concentration of the oxidizing agent is 0.1-15%, the concentration of the complexing agent is 0.01-15%, the concentration of the bifunctional reagent is 0.001-5%, and the surfactant is The concentration is 0.001-5% and the carrier is the balance, and the above percentages all refer to the mass percentage of the entire composition.

The abrasive particles are silica, alumina, ceria and/or titania.

The oxidizing agent is hydrogen peroxide, ferric nitrate, organic peroxides and/or inorganic peroxides. The surfactant is a cationic, anionic, amphoteric and/or neutral surfactant.

The surfactant is a fatty alcohol polyoxyethylene ether, polyvinyl alcohol, polyoxyethylene alkylamine and/or mercapto alcohol amide. The polishing slurry further includes one or more of a dispersing agent, a catalyst, and a pH adjusting agent.

The positive progressive effects of the present invention are: reducing the concentration of abrasive particles in the polishing slurry, reducing the downward force applied in the CMP process, thereby improving the surface quality of the substrate and minimizing defect levels while maintaining The desired removal rate. Summary of the invention

Preferred embodiments of the present invention are given below to explain the technical solutions of the present invention in detail.

Example 1

10 wt% of silica particles having an average particle diameter of 0.1 μm, 5.0 wt% of oxygen water, 0.1 wt% of benzotriazole 5-sulfonate, 0.5 wt% of citric acid, 0.01 wt% of fatty alcohol polyoxyethylene ether, others water. Lower pressure: lpsi, polishing disc speed: 50 rpm, polishing head speed: 75 ipm, polishing fluid flow rate: 150 mL/min.

Example 2

5 wt% silica particles having an average particle diameter of 0.1 μm, 5.0 wt% hydrogen peroxide, 0.1 wt% 2-amino-2-ethyl-propylene glycol, 0.5 wt% citric acid, 0.01 wt% fatty alcohol polyoxyethylene ether, others For water. Downforce: lpsi, polishing disc speed: 50 rpm, polishing head speed: 75 rpm, polishing fluid flow rate: 150 mL/min.

Example 3

8 wt% alumina particles having an average particle diameter of 0.1 μm, 1.0 wt% ammonium thiosulfate, 0.1 wt% lysine, lwt% EDTA, 0.1% acrylic acid and acrylate copolymer, and others are water. Downforce: lpsi, polishing disc speed: 50 rpm, polishing head speed: 75 rpm, polishing fluid flow rate: 150 mL/min. 10 wt% of silica particles having an average particle diameter of 0.1 μm, 5 wt% of oxygen water, 0.1 wt% of 5-carboxybenzotriazole, 5 wt% of EDTA, 5% of polyvinyl alcohol, and others are water. Downforce: lpsi, polishing disc speed: 50 rpm, polishing head speed: 75 rpm, polishing fluid flow rate: 150 mL/min.

Example 5

5 wt% of silica particles having an average particle diameter of 0.1 μm, 0.5 wt% of n-butanolamine, 1.0 wt% of succinic acid, 0.1 wt% of acrylic acid and acrylate copolymer, and others are water. Downforce: lpsi, polishing disc speed: 50 rpm, polishing head speed: 75 rpm, polishing fluid flow rate: 150 mL/min.

Example 6

Lwt% silica particles having an average particle diameter of 0.1 μm, 15 wt% hydrogen peroxide, 5 wt% 4-carboxyimidazole, 0.01 wt% EDTA, 0.001 wt% acrylic acid and acrylate copolymer, and others are water. Lower pressing force: lpsi, rotating disk speed: 50 rpm, polishing head rotation speed: 75 rpm, polishing liquid flow rate: 150 mL/min.

Example 7

30 wt% of silica particles having an average particle diameter of 0.1 μm, 0.1 wt% hydrogen peroxide, 0.001 wt% histidine, 15 wt% EDTA, 0.5% wt acrylic acid and acrylate copolymer, and others are water. Lower pressing force: lpsi, rotating disk speed: 50 rpm, polishing head rotation speed: 75 rpm, polishing liquid flow rate: 150 mL/min.

Claims

Rights request

A polishing slurry comprising abrasive particles and a carrier, characterized by further comprising a bifunctional reagent.

2. The polishing slurry according to claim 1, wherein the bifunctional reagent is XRY; wherein X is a hydrophilic group, Y is a group capable of bonding to a surface of a metal substrate, and R is QrC ₆ Amidino or C ₆ arylene.

3. The polishing slurry according to claim 2, wherein R is an anthracene group of d-.

The polishing slurry according to claim 2, wherein X is a hydroxyl group, a carboxyl group, a sulfuric acid group, a sulfonic acid group or a phosphoric acid group; and Y is an amino group, a triazolyl group, an imidazolyl group or an ammonium group.

The polishing slurry according to claim 1, characterized in that the polishing slurry further comprises an oxidizing agent, a complexing agent and/or a surfactant.

6. The polishing slurry according to claim 5, wherein the abrasive particles have a concentration of 1 to 30%, the oxidizing agent has a concentration of 0.1 to 15%, and the complexing agent has a concentration of 0.01 to 15%. The concentration of the bifunctional reagent is 0.001-5%, the concentration of the surfactant is 0.001-5%, and the carrier is the balance, and the above percentages all refer to the mass percentage of the entire composition.

The polishing slurry according to any one of claims 1 to 6, wherein the abrasive particles are silica, alumina, ceria and/or titania.

8. A polishing slurry according to claim 5 or 6, characterized in that the oxidizing agent is hydrogen peroxide, ferric nitrate, organic peroxide and/or inorganic peroxide.

9. A polishing slurry according to claim 5 or 6, characterized in that the surfactant is a cationic, anionic, amphoteric and/or neutral surfactant.

The polishing slurry according to claim 9, wherein the surfactant is fat Alcohol polyoxyethylene ether, polyvinyl alcohol, polyoxyethylene alkylamine and/or alkyl alcohol amide.

A polishing slurry according to claim 5 or 6, wherein the polishing slurry further comprises one or more of a dispersing agent, a catalyst and a pH adjusting agent.