Micro C systems use a process called RTX^™ - a combination of rapid thermal processing, rapid thermal annealing and rapid thermal chemical vapor deposition (RTCVD) to etch the silicon wafer surface. The overall RTX system is called a cluster tool - an automation hub that holds up to three process modules and a cooling chamber. The process modules contain all the automation equipment needed to enable advanced semiconductor wafer processing.

Cluster tool developers found that working with complex programming languages increased development time and training, and computer crashes were frequent and hard to correct. Additionally, the semiconductor industry requires a standard interface and uses multiple RS232 communication ports in systems developed for the industry. These requirements posed additional challenges for developing systems quickly and easily.

According to Dr. Imad Mahawili, president of Micro C, the traditional method for controlling wafer processing systems left a lot of room for improvement. "We knew that there were better methods for control, and that we'd need to look beyond traditional semiconductor industry techniques to find them," he said.

Ultimately, Micro C needed an automation solution that would provide supervisory control of the RTX process, control of functions specific to each of the different modules, and ability to perform 3-axis motion control required for each module. It also needed an easy-to-configure, reliable interface for operator input and feedback and a system that was easy to install and configure.

Micro C also knew that Allen-Bradley controllers would offer the speed, flexibility, reliability and ease-of-use that was needed to develop and run the RTX systems. They also would integrate easily with Rockwell Software programs. When faced with developing a new user interface, Micro C felt the Rockwell Software RSView32 operator interface would be reliable for the multi-tasking required, would help decrease the development time to create the software and would customize operator interface screens to more accurately reflect the specific application needs of customers.

"By using Rockwell Software products, we've cut down development time by at least two or three years for a product as complex as ours," said Cutro. "The decrease in time is attributed to the Allen-Bradley controllers and the Rockwell Software product, coupled with the value-added support we've received from Rockwell Automation that has kept us on the edge of development."

Previously, in a proprietary system, changing a simple parameter required users to enter a code command, hit the return and write the whole script for the entire process to change one flow parameter. The user now simply enters a value into a field under a visual picture. This simple change cut user training time and can decrease system downtime because it is simpler to troubleshoot problems.

Additionally, Micro C uses the Microsoft Visual Basic for applications (VBA) development language, embedded within RSView32 as an offline recipe editor. Micro C can easily develop 50 recipes in the controller. Customers also have the capability to design additional recipes at their desks, transport the recipes to the system and download them into the controller. This gives Micro C and users more flexibility in adapting the systems to new recipes.

The use of open automation products also offered better integration of equipment for easier systems development, making system use more flexible for customers and increasing system uniformity, repeatability and reliability. By far, the openness of the software development tools helped Micro C drastically cut system development time and also offers users control options not previously available. When Allen-Bradley and Rockwell Software products were used on a complex off-the-shelf wafer handling system for cluster tools, the development time was cut from the typical 12 to14 months, to just six weeks.

Micro C felt that Rockwell Software RSView32 would be reliable for the multi-tasking they required.

Dr. Mahawili added, "We were able to achieve 25 percent more throughput in wafer handling using the Rockwell Automation control system." He is just as impressed by Rockwell Automation's global support. "Regardless of location, all our customers recognize the Rockwell Automation name, and know that they can access service in their area," said Cutro. "Because of this global support, we can send our customers to a local Rockwell Automation support service, and feel confident that their concerns will be handled."

TABLE OF CONTENTS