Tribological Characterization of Anionic Supramolecular Assemblies in Post-STI-CMP Cleaning Solution Using a Novel Post-CMP PVA Brush Scrubber

We have shown how different micellar (SDBS) vs. polyelectrolytic (PSSA) supramolecular assemblies in post-CMP cleaning solutions differ in their tribological performance when used in a novel PVA scrubber for 300-mm silicon dioxide wafer cleaning. Significant differences in real-time shear force and coefficient of friction data from the wafer-solution-brush interface (both in time domain as well as frequency domain) have been attributed to differences in each supramolecule’s chemical functionality and structure, which in turn, have been correlated to wafer-level defects. The work has underscored the importance of measuring the tribological attributes of post-CMP cleaning processes in an effort to improve cleaning performance.

Ultrafine Particle Removal in the Wafer Cleaning Process Using an Aqueous Solution with a High Concentration of Dissolved O3 and HF

Sulfuric Peroxide Mixture (SPM, H2SO4 + H2O2) has been widely used in semiconductor manufacturing processes due to its high reactivity and attractive price. However, SPM releases SO42- ions that can be high impact on the environmental contaminations. Therefore, the SPM process requires a high cost wastewater treatment. So, the development of alternative chemicals has been becoming an important task in the semiconductor manufacturing process. In this paper, we evaluated the feasibility of replacing SPM with dissolved ozone water (DIO3) in the wafer cleaning process, and confirmed that the Particle removal efficiency (PRE) was improved around 68% by mixing with diluted hydrofluoric acid (DHF). And, the PRE was also increased when the concentration of ozone in dissolved ozone water increased. Additionally the PRE was improved up to 98% by combining physical cleaning after O3 process.

High Performance, Eco-Friendly SPM Cleaning Technology Using Integrated Bench-Single Wafer Cleaning System

Batch SPM systems do not meet the current clean specification/requirements below 28nm. Single wafer SPM systems use a high volume of chemistry which runs to drain, while meeting the cleaning specifications below 28nm. The work in this paper describe the use of a batch SPM system and a single wafer clean in an integrated system, Ultra-C Tahoe which results in meeting the technical specification and using less that 80% of the SPM chemistry used in single wafer systems. The data collected shows this new system meet the specifications, whilst saving more than 80%of SPM chemistry.

Study on Uniform Deposition on 300 mm Silicon Wafer with Sub-100 nm Sized Particles for Cleaning Application

A study for uniform deposition on whole area of wafer was conducted to help check the uniformity of cleaning technology between wafer center to edge. A new method of particle deposition was devised different from the conventional studies using the center nozzle and electric field. Our deposition chamber features wafer rotating method and deposition by the principle of convection and diffusion. In this study, we focused on the effect of wafer rotation speed and rotation number to particle deposition result. After setting the optimum condition, fine results with well deposited shape on whole area of the wafer and outstanding particle size uniformity of more than 70% were obtained. Although particle size shift phenomenon occurred in the measurement result using SP5 due to the intrinsic principle, SEM analysis demonstrated that particles with 60, 80 nm sized silica particles were well deposited on wafer. We believe the standard wafer made by our particle deposition system could be utilized and helpful for performance evaluation and development of wafer cleaning technologies.

Optimal Design of High-Frequency Induction Heating Apparatus for Wafer Cleaning Equipment Using Superheated Steam

In this study, wafer cleaning equipment was designed and fabricated using the induction heating (IH) method and a short-time superheated steam (SHS) generation process. To prevent problems arising from the presence of particulate matter in the fluid flow region, pure grade 2 titanium (Ti) R50400 was used in the wafer cleaning equipment for heating objects via induction. The Ti load was designed and manufactured with a specific shape, along with the resonant network, to efficiently generate high-temperature steam by increasing the residence time of the fluid in the heating object. The IH performance of various shapes of heating objects made of Ti was analyzed and the results were compared. In addition, the heat capacity required to generate SHS was mathematically calculated and analyzed. The SHS heating performance was verified by conducting experiments using the designed 2.2 kW wafer cleaning equipment. The performance of the proposed pure Ti-based SHS generation system was found to be satisfactory, and SHS with a temperature higher than 200 °C was generated within 10 s using this system.