How the Advanced Ozone Cleaning Process Improves Wafer Yields and Reduces Costs

How the Advanced Ozone Cleaning Process Improves Wafer Yields and Reduces CostsEditor’s Note: This article was originally published in January 2017 and has been updated with additional information and reposted in April 2023.

Modutek’s advanced ozone cleaning is a highly effective method for removing contaminants from wafers. The process involves using ozone gas, which is a highly reactive oxidant, to break down and remove organic and inorganic contaminants from the surface of the wafer. The process is typically performed in a closed chamber that is designed to contain and recirculate the ozone gas.

How Advanced Ozone Cleaning Works

The advanced ozone-cleaning process works by exposing the wafers to a controlled amount of ozone gas. The gas is generated on-site using an ozone generator and is then injected into the cleaning chamber. The wafer is then exposed to the ozone gas for a specific amount of time, which can range from a few seconds to several minutes, depending on the type and level of contamination.

During the exposure time, the ozone gas breaks down and oxidizes the organic and inorganic contaminants on the wafer surface, converting them into carbon dioxide, water, and other harmless byproducts. The byproducts are then removed from the chamber through a ventilation system, leaving the wafer surface clean and free of contaminants.

The advanced ozone-cleaning process is highly effective at removing a wide range of contaminants, including organic and inorganic compounds, particles, and metals. Additionally, the process is environmentally friendly and does not generate any hazardous waste or byproducts. Overall, advanced ozone cleaning is a safe and effective method for removing contaminants from wafers, resulting in improved yields, reduced costs, and increased productivity.

Advantages and Benefits of Advanced Ozone Cleaning

Advanced ozone cleaning is a highly effective method for removing contaminants from wafers, which can significantly improve wafer yields and reduce manufacturing costs. Unlike traditional cleaning methods, such as wet cleaning and plasma cleaning, advanced ozone cleaning uses ozone gas to break down and remove organic and inorganic contaminants from wafers. In this article, we will discuss the benefits and advantages of using advanced ozone cleaning in the semiconductor manufacturing process.

Improved Cleaning Performance

One of the main advantages of using advanced ozone cleaning is its superior cleaning performance. Ozone gas is a highly reactive oxidant that can effectively remove a wide range of contaminants, including organic and inorganic compounds, particles, and metals. Compared to traditional cleaning methods, advanced ozone cleaning can achieve much higher levels of cleanliness, which can lead to improved wafer yields and reduced defect rates.

Reduced Chemical Usage

Another benefit of using advanced ozone cleaning is its reduced chemical consumption. Traditional cleaning methods often require large quantities of chemicals, which can be expensive and potentially hazardous. In contrast, advanced ozone cleaning uses only a small amount of ozone gas, which is generated on-site and does not require the storage or handling of hazardous chemicals. This can result in significant cost savings and reduced environmental impact.

Better Process Control

Advanced ozone cleaning also offers improved process control compared to traditional cleaning methods. By precisely controlling the amount and duration of ozone exposure, the cleaning process can be optimized for each specific application. This can result in improved process repeatability, reduced variability, and higher product quality.

Reduced Downtime

Using advanced ozone cleaning can also lead to reduced downtime and increased productivity. Traditional cleaning methods often require longer cleaning cycles and can result in extended equipment downtime. In contrast, advanced ozone cleaning can be performed quickly and efficiently, reducing the amount of time equipment needs to be offline. This can result in increased equipment utilization and improved manufacturing throughput.

Lower Cost of Ownership

Finally, advanced ozone cleaning can result in a reduced cost of ownership for semiconductor manufacturers. By improving wafer yields and reducing defect rates, advanced ozone cleaning can lead to increased revenue and reduced waste. Additionally, the reduced chemical consumption, improved process control, and reduced downtime can result in lower operating costs and increased profitability.

The Bottom Line

Advanced ozone cleaning is a highly effective method for removing contaminants from wafers, which can significantly improve wafer yields and reduce manufacturing costs. With its superior cleaning performance, reduced chemical consumption, improved process control, reduced downtime, and reduced cost of ownership, advanced ozone cleaning is an ideal choice for semiconductor manufacturers looking to improve their manufacturing processes.

Modutek Provides Solutions for Manufacturers

Modutek offers equipment for applying the ozone-cleaning process to semiconductor manufacturing and can help determine the ideal configuration for a particular application. The company also delivers equipment for traditional chemical bath cleaning methods and is therefore ideally placed to advise how the new ozone cleaning methods can improve production. Semiconductor manufacturers can take advantage of this capability to cut costs and increase productivity at their facility. Contact Modutek for a free consultation to discuss your specific process requirements.

How Advanced Ozone Cleaning Reduces Chemical and Solvent Usage

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.

Using the Advanced Ozone Cleaning Process to Improve Wafer Yields

Using the Advanced Ozone Cleaning Process to Improve Wafer YieldsTwo key goals for semiconductor manufacturers are to increase process yields and to reduce chemical usage. Wet process semiconductor manufacturing is sensitive to wafer contamination by microscopic particles that increase final product rejection rates and reduce output quality. The ozone cleaning process can reduce particle counts and improve wafer yields by reducing the number of defective products. At the same time, cleaning organic contaminants from the wafer with ozone reduces the use of expensive and toxic chemicals. Modutek’s Advanced Ozone Cleaning Process allows semiconductor manufacturing facilities to increase throughput and output quality while reducing operating costs.

How Advanced Ozone Cleaning Improves Wet Process Line Performance

Modutek’s Advanced Ozone Cleaning Process uses ozone to remove organic contaminants from the surfaces of silicon wafers during wet bench processing. Ozone is used with either room temperature acidic acid or chilled DI water to clean wafers without aggressive chemicals. In addition to saving money due to reduced use of chemicals, ozone cleaning takes less space and is faster than many chemical-based wet bench processes.

Ozone cleaning takes place in Modutek’s DryZone System. Modutek has developed the Coldstrip sub ambient process and the Organostrip process that operates at room temperature. Both ozone cleaning processes deliver reduced particle counts and increased yields.

The Coldstrip process operates at four to ten degrees centigrade and introduces ozone into the ozone chamber after the wafers have been rinsed with de-ionized water. The rinsing removes non-organic contamination while the ozone combines with the carbon of the organic contaminants to produce carbon dioxide. After completion of the Coldstrip process, the wafers are clean and almost particle-free.

In the Organostrip process, the wafers are rinsed with acidic acid containing ozone. The acidic acid used has extremely high ozone solubility and the high ozone level producing produces rapid decomposition and oxidation. The ambient temperature process eliminates the use of toxic chemicals and the process waste products are harmless.

The Modutek Advanced Ozone Cleaning Process Improves Performance While Saving Money

Modutek developed the Advanced Ozone Cleaning Process to achieve low particle counts and to reduce the use of harmful chemicals. Reduced particle counts are needed for the more compact architecture of modern semiconductors where a single particle can cause defects or lower component quality. Reduced use of chemicals is mandated by increasingly strict environmental regulations while chemical purchase, storage and disposal costs continue to rise. The patented Modutek Advanced Ozone Cleaning Process successfully addresses these issues.

Specific benefits from using the ozone cleaning process include the following:

  • Better wafer yields due to lower particle count
  • Savings from reduced use of chemicals
  • Compatibility with metal films
  • Safer work environment due to absence of toxic substances
  • More environmentally friendly operations
  • Space saving due to more compact equipment
  • No toxic waste disposal issues

Modutek’s Advanced Ozone Cleaning Process increases throughput due to shorter cleaning times and higher yields while cost savings due to reduced use of chemicals are substantial. Semiconductor manufacturers can improve the overall performance of their facility by incorporating Modutek’s DryZone cleaning stations in their wet process lines.

Modutek Can Help Customers with Innovative Solutions

The Advanced Ozone Cleaning Process is one example of Modutek’s initiatives to improve the performance of wet process technology stations and help customers address common problems. The patented process solves issues with current semiconductor manufacturing and helps customers with product quality and with their bottom line.

With Modutek’s emphasis on customer service and on working with customers to improve wet process technology, the company continues to be a leader among semiconductor equipment manufacturers. Customers can rely on Modutek to supply the equipment they need and to provide the support ensuring the equipment meets or exceeds performance expectations.