Wet Etching and Wafer Cleaning

As the requirements for increased device performance and reliability have become more and more challenging in VLSI and ULSI silicon circuit technology, techniques to avoid contamination and processes to generate very clean wafer surfaces have become critically important. 

Many cleaning operations are necessary in the course of semiconductor manufacturing and must be performed at certain critical processing steps. To ensure a fast, selective, uniform and cost effective cleaning, the Center Nanoelectronic Technologies provides a state-of-the-art cleaning platform. 

As a chain link between suppliers and fab we are able to screen, evaluate and optimize new chemicals and processes from laboratory scale up to testing on own 2x nm node test wafers. 

Applications

• 2x nm technology node
• From beaker test to 300 mm industry scale
• PostEtchResidualRemoval (PERR)
• Photoresist stripping
• Lithography stack rework
• Dual damascene metal hard mask etch
• Bath life time evaluation
• Consumable benchmarking

In semiconductor manufacturing, precise wafer cleaning is essential for process reliability and high-quality sensor, MEMS, and IC production. Our advanced wet etching and cleaning systems ensure the efficient removal of organic, metallic, and particulate contaminants on 6" and 8" wafers.

Standardized Chemical Wafer Cleaning

Our system provides reliable cleaning of 6" and 8" wafers using carefully controlled chemical processes:

• HF (H₂O:HF 50:1) – Removes oxide layers formed during previous process steps.
• SPM (H₂O₂:H₂SO₄ 1:4) – Efficient removal of organic residues.
• SC-1 (APM, H₂O:H₂O₂:NH₄OH 50:2:1) – Particle removal for ultra-clean surfaces.
• SC-2 (HPM, H₂O:H₂O₂:HCl 50:1:1) – Eliminates metallic contaminants.
• NID (Nitrogen-Isopropanol Dryer) – Gentle drying using the Marangoni principle.

Polymer Residue Removal

Our system is designed for the removal of polymer residues generated during plasma etching of metal and oxide layers:

• Batch tool for efficient process control.
• EKC-265 – Solvent-based cleaning mixture for high surface quality.
• Optimized for 8" wafer processing.

Surface Particle Control

The system combines mechanical and chemical cleaning for particle-free surfaces:

• Brush and nanospray technology to remove fine contaminants.
• Spin dry wafer drying, optionally with hotplate and coldplate.
• Compatible with 6" and 8" wafers.

Manual Wet Benches for Specialized Etching

Our manual wet benches support a wide range of precise etching and cleaning processes:

• Si Etching: 25% TMAH + H₃PO₄ with one-side wafer protection.
• SiO₂ Etching: BOE (1% HF) with wafer holder protection.
• Ti, Al, Al₂O₃, and Nitride Etching with customized acid solutions.
• Polymer Residue Removal: H₂SO₄/Ammonium Peroxodisulfate.
• Lift-Off and Photoresist Removal: Current NMP process; future MLO-07 with IPA and/or DI water.
• Drying Options: SRD or NID dryers for gentle Marangoni-based wafer drying.

Our Advantages

Our systems and processes deliver:

• Maximum process control and reproducibility.
• Superior surface cleanliness for MEMS, sensors, and ICs.
• Flexibility for different wafer sizes and materials.
• Future-oriented solutions with solvent-free alternatives.

With cutting-edge wet etching and wafer cleaning technologies, we set the standard for efficiency, precision, and sustainability in semiconductor manufacturing.

• Evaluation of new equipment and materials under industry standard conditions
• AMAT Semitool Raider SP | DNS FC3000 and BREWER Science flexible labtool
• Pre- and post-processing for optimization of individual process steps
• Inline metrology
• Professional contamination management
• Professional IP management and licensing
• Close connection to industry
• Availability of patterned 300 mm short loop test wafers