As environmental concerns mount and regulatory compliance becomes more difficult, companies that reduce the use of hazardous chemicals and solvents will have a competitive advantage. In addition to reducing costs, the use of fewer corrosive chemicals improves workplace safety and can lead to better semiconductor manufacturing facility performance. Modutek’s patented advanced ozone cleaning process saves money and reduces the contaminating particle count on wafer surfaces. Depending on process requirements, ozone cleaning can out-perform traditional wafer cleaning with harsh chemicals. Modutek’s ozone cleaning process is compact, fast, and safe.
Advanced Ozone Cleaning Converts Organic Impurities to Carbon Dioxide
Modutek has developed the Cold Strip sub ambient process that operates with deionized water and the Organostrip process that uses a mild acid at room temperature for photo resist strip. This also eliminates the use of NMP solvent base strippers. Both use ozone to clean organic contaminants from wafer surfaces and both leave harmless residues that allow for disposal without special neutralizing procedures.
The Cold Strip Advanced Ozone Cleaning Process operates at four to ten degrees centigrade and uses deionized water to strip silicon wafers of water-soluble inorganic impurities. After the wafers are rinsed with deionized water, ozone is introduced into the chamber. The ozone reacts with the remaining organic impurities and converts them to carbon dioxide. Particle contamination is reduced as well because the ozone reacts with organic particles. Wafers are more effectively cleaned with a reduced particle count.
In the Organostrip process, wafers are rinsed with a solution of a mild acid and ozone at room temperature. The acid has a high ozone solubility that lets the ozonated solution remove organic compounds from the wafer surfaces quickly and completely. The process is compatible with metals such as gold, copper, and aluminum, and the waste products of the Organostrip process are not hazardous.
Modutek uses its DryZone solvent gradient dryer for the Advanced Ozone Cleaning Process that the company developed to address customer concerns. Customers experienced high particle counts and issues with the use of hazardous chemicals, including their effect on the environment. The developed process successfully addresses these issues and delivers effective wafer cleaning.
Modutek’s Advanced Ozone Cleaning Process Provides Substantial Benefits
Modutek developed the Advanced Ozone Cleaning Process to address specific customer concerns, but the Cold Strip and Organostrip processes also improve wafer cleaning and facility operations. The benefits of using ozone cleaning include the following:
- Reduced cost for process chemicals. The acids used in a traditional wafer cleaning process, such as sulfuric or hydrochloric acids, are expensive, and the cleaning processes such as Piranha clean use substantial volumes of chemicals. Ozone and the mild acids or solvents used in ozone clean are less expensive and the solutions last longer.
- Reduced cost for chemical handling. The storage, delivery, and disposal of hazardous chemicals used for traditional wafer cleaning is expensive. The handling of ozone and the mild chemicals used for ozone cleaning requires no special measures.
- Improved workplace safety. The chemical baths used for traditional wafer cleaning often operate at high temperatures and they can be dangerous. The ozone cleaning process chemicals are safe and the operation is done at sub ambient or at room temperature.
- Higher throughput. Advanced ozone cleaning takes less time than traditional cleaning methods.
- Improved yields. Ozone cleaning reduces particle counts and results in higher output quality with fewer product defects.
Modutek’s Continued Process Improvement Delivers Innovative Solutions for Customers
Modutek works closely with customers to identify new concerns and solve existing processing problems. Using extensive in-house experience and expertise in wet process technology allows Modutek to provide innovative solutions to meet customer needs. New wet process steps such as Advanced Ozone Cleaning can help customers improve semiconductor manufacturing facility performance and increase profitability.
