Use Of Oxidizers In Your CMP Process

Oxidizers play a crucial role in CMP polishing processes. Here's an explanation of their use:

1. Oxidizers in Slurry Composition:
   

   • CMP slurries consist of abrasive particles, chemicals, and additives suspended in a liquid carrier. Oxidizers are often included in the chemical composition of the slurry.

   • Common oxidizers used in CMP slurries include hydrogen peroxide (H2O2) and ozone (O3). These substances act as oxidizing agents, promoting the removal of material from the wafer surface.

1. Material Removal Mechanism:
   

   • During CMP, the oxidizers enhance the chemical removal of material from the wafer surface. This is particularly important when polishing materials that are resistant to mechanical abrasion alone.

   • The oxidizing agents react with the material on the wafer surface, forming oxides or other soluble compounds that can be easily removed in the slurry.

1. Selectivity Enhancement:
   

   • Oxidizers can improve the selectivity of CMP, enabling the preferential removal of certain materials over others. This selectivity is essential when different materials with varying hardness or etch rates are present on the wafer.

   • By tailoring the CMP slurry composition, manufacturers can achieve specific removal rates for different materials.

1. Chemical Stability and Shelf Life:
   

   • Oxidizers contribute to the chemical stability of the CMP slurry. They help prevent the degradation of the slurry components over time, extending the shelf life of the polishing solution.

   • This stability is crucial for maintaining consistent polishing performance during the manufacturing process.

1. Surface Cleaning:
   

   • In addition to material removal, oxidizers contribute to the cleaning of the wafer surface. They can oxidize and remove organic and metallic contaminants, ensuring a clean and defect-free surface.

1. Controlled Oxidation:
   

   • The use of oxidizers allows for controlled oxidation of the wafer surface. This controlled oxidation can be critical for achieving the desired surface properties and improving the overall performance of semiconductor devices.