How Automated Wafer Fabrication Equipment Optimizes Process Control

Fully or semi-automated silicon wafer fabrication equipment can reduce errors and improve repeatability in wafer processing while at the same time increasing flexibility. Automatic controls let operators change process parameters if required for different processes or for process optimization.

Once a process runs in an optimized fashion, automated controls allow operators to make sure that the process continues to run the same way, either in a continuous mode or in batch processing. Automatic controls can ensure that an error-free process increases productivity, improves output quality, and reduces waste.

Automatic Controls Increase Operating Flexibility

Automatic controls use programmable software to specify how process steps operate and their sequence. The software determines the timing, chemical dosages, wafer transfers between stations, waste chemical neutralization, and chemical disposal. Once operators have programmed a process, they can carry out test runs and find where settings could be changed to improve the process results.

This means a process can be adapted to reflect changing requirements or can be changed so it produces better outcomes. At the same time, the process software in both semi-automated and fully automatic stations controls robotics that handles the wafers and reduce particle contamination. Automatic controls with the associated robotics can save money and produce semiconductor products with fewer defects and closer adherence to specifications.

Automated Operation with Robotics Contributes to Optimized Operations

Robotics handle and transfer the silicon wafers are a key part of the automated semiconductor manufacturing operations. For fully automated lines, multiple robots will hand the wafers down the process line. The robots have to operate to an extremely high level of precision to avoid damaging the delicate wafers and to place them precisely in the right locations. With the right robotics, properly programmed and fully automated, a semiconductor processing line can increase throughput and perform reliably to meet delivery times and volumes. Optimized process control combined with robotic speed and reliability can reduce costs and improve semiconductor fabrication facility performance.

For semi-automatic wafer fabrication equipment, the robotics generally handle less processing, however, Modutek has developed a new rotary rotation robot that can handle more process steps. The use of the rotary rotation robot can reduce the overall length and footprint size of a conventional station in a space-saving design. This allows manufacturing facilities and research labs with limited space to install semi-automatic fabrication lines using smaller stations with new robotics. As is the case for fully automated stations, semi-automatic controls and robotics can deliver increased speed, higher reliability, and improved facility performance.

Selecting the Right Automation Solution

Whether it is a fully automated process line or semi-automatic wafer processing equipment, automation can improve chemical handling and the cleaning and etching of silicon wafers. Software control ensures that chemical mixtures are correct, the timing of process steps is accurate and wafers are moved and transferred with a minimum of particle contamination. This allows wafer fabrication processes to be accurately completed with optimum efficiency and generates fewer defective components.

With more accurate process control, etch rates and yields can be higher and comprehensive tracking of variables delivers a complete picture of the process. Once the automated process has run for a large number of jobs, a saved software library gives manufacturers the ability to reuse previous configurations and the flexibility to make specific changes in the previous process runs.

Modutek Provides In-house Expertise and Support

With over 40 years of experience in wet bench technology and extensive in-house expertise in manufacturing operations, Modutek can help customers choose the right level of automation for their semiconductor fabrication line. Modutek offers free consultations and can discuss how different levels of automation and robotics usage can impact fabrication line performance. In general, the right level of automation for a semiconductor fabrication facility is one that improves process control and optimization and delivers long-term cost savings while improving output. Contact Modutek for a free consultation to discuss the details of your manufacturing equipment requirements.

Designing Chemical Delivery Systems to Meet Facility Requirements

Because semiconductor manufacturing facilities use a variety of chemicals to clean, etch and process silicon wafers, chemical delivery systems are critical for ensuring that operations run smoothly. Chemical handling equipment delivers or collects the required chemicals for the safe disposal of the chemical waste. Effective chemical delivery systems remove concerns about the availability and correct mixture of process chemicals and allow operators to focus on issues directly affecting silicon wafer fabrication, such as wafer cleaning, etch rates, and particle contamination. When chemical delivery systems exactly meet facility requirements, a focus on the fabrication processes lets operators optimize production and helps improve output.

Adapting Receiving and Storage of Chemicals to Facility Requirements

Chemical delivery depends on how many different chemicals a facility requires and the volume of the chemicals used. Chemical characteristics such as toxicity also have to be considered. For facilities using a variety of chemicals in varying quantities, a special area may be needed to centralize reception and storage functions.

For small volumes of chemicals, a standard drum located near the process may be the most convenient. For large volumes, receiving and storing chemical totes monitored with a load cell to track chemical use could be the best solution. For dangerous chemicals, containment of possible leaks and special safety measures may be required to ensure compliance with environmental and safety regulations. A competent manufacturer of chemical delivery and storage systems can evaluate these factors and make corresponding recommendations.

Ensuring Timely and Reliable Delivery of Chemicals to the Process

The key function of chemical delivery systems is to ensure that the required chemicals are provided in precise amounts as needed for the process. Silicon wafer fabrication steps clean and etch wafers with mixtures of chemicals that have to be delivered to process tanks. Each step requires precise quantities of chemicals delivered in sequence and at timed or process-dependent intervals. Each facility has different process steps and different chemical delivery requirements. A well-designed chemical delivery system will reliably provide exactly the right chemical in the specified volume at the correct time.

Collecting and Disposing of Used Chemicals Safely

Once a process step is complete, the chemical mixture that remains is often still chemically active, toxic and dangerous. The wafers will have been removed from the chemical bath and the used chemicals need to be safely treated or collected and disposed. For example, acids used in wafer etching are hazardous for operators, harmful for the environment and even the vapors may be dangerous.

Disposal of chemical waste has to be in accordance with local safety and environmental regulations. The chemical system can either drain the chemical waste and send it to an on-site chemical neutralization system for treatment, or to storage in a chemical collection container. Used chemicals in chemical collection containers can be picked up by service providers that specialize in chemical disposal. In either case, the chemical handling has to be carried out safely while containing any leaks or spills.

Modutek’s Expertise with Chemical Delivery Systems

Modutek has extensive experience designing and building customized chemical delivery systems. With in-house expertise in designing and supplying a full line of chemical handling equipment and systems, Modutek can evaluate a facility’s chemical delivery needs and make corresponding recommendations. If you need guidance on selecting the right chemical handling equipment and systems for your facility, contact Modutek for a free consultation.