Beyond overall equipment efficiency: what's your overall fab efficiency?

07/01/2002

Here's a chilling thought: a $3 billion 300mm IC fab depreciates at a rate of $50,000/hr. In a 24-7 world, that's $120,000 a day, $840,000 a week. The point is obvious: new fabs must quickly attain operating efficiency or risk becoming enormous money pits. In order to do that, there must be a shift in the way chipmakers think. No longer can the focus be on achieving a respectable return on investment (ROI) on a new tool; we must start thinking in terms of ROI for an entire new fab.

This means that the previous goal of overall equipment efficiency will expand to overall fab efficiency and the narrow concept of statistical process control will broaden into process management and advanced process control.

Fortunately, the advent of web-based communication links has opened up a new opportunity for collaborative process management (CPM), a method in which processes are managed as a system rather than as isolated events. By connecting process steps in this way and allowing data to be effortlessly fed up- or downstream, chipmakers can more quickly and effectively make the critical adjustments necessary to achieve profitability.

This capability relies on the presence of an open database architecture and standardized web communication protocols, and there are three clear requirements of CPM tools: data acquisition, analysis, and automated action. For optimal functionality, data must be shared across the entire corporation, from the fab operator to the sales force, with each player viewing the information in the format most useful to their function. With that, any strategic and corrective activities based on having the right information at the right time can take place.

For example, as a web-based toolset, Electroglas' software products allow application developers and OEMs to effectively create customized process optimization systems or integrate web-based monitoring, analysis, and excursion-alarm capabilities into existing applications. The toolset gives users full access to an extendible computational engine with customizable graphical display and statistical analysis methods linked to dynamic, real-time web publishing and reporting functions.

Processes aren't the only things that need to change. Just like OEMs in pharmaceutical, chemical, and health care industries, semiconductor OEMs must constantly adjust the way they view the world and their business if they are to remain successful. This means that chipmakers must take the fab depreciation numbers mentioned above to heart. They must begin judging each individual tool in terms of how it is linked to the entire process line across the fab and across the enterprise, rather than just on its individual performance, throughput, and efficiency.

Because IC fabs have for years been collecting and analyzing process tool operating parameters, one would think we have already implemented corrective action plans across the enterprise when abnormal events occur, right? Unfortunately not. Some fabs may have some of this in place, but often these activities are narrowly focused and not interconnected. In spite of the fact that it is the semiconductor industry that ultimately makes connectivity possible, we have been slow to get connected ourselves.

Semi standards have been implemented to help overcome this problem. However, in the end, we still find appropriate corrective action is often delayed or not defined. This is in part due to an inherent and understandable hesitancy among IC manufacturers and OEMs to put tool and process recipe and proprietary knowledge in a place where it might be hacked into and accessed by a competitor.

There needs to be a greater understanding of the power of the Internet as the most effective way to truly integrate "best-of-breed" products and technologies and deploy fab-wide systems. As a vendor to both IC manufacturers and their OEMs, it is our job to convince both groups that uniting the proven capabilities of their products and applications will strengthen their value-add by giving them an effective method for process optimization.

To be successful in the 300mm world, we must establish web-connected CPM strategies with process tools and control systems using feed-forward and feed-backward real-time process state and equipment state data. They will prove to be a key element in the drive to maximize overall fab efficiency.

Tom Simas,
Electroglas Inc.

Tom Simas is business manager for CPM tools at the EGsoft Division of Electroglas Inc., 257 SW Madison Ave., Corvallis, OR 97333; ph 541/753-5382, e-mail [email protected].