Advanced process control system description of an easy-to-use control system incorporating pluggable modules

We have developed an advanced process control (APC) system into which it is easy to plug the calculation methods and formulae for process control which are appropriate for a given product, recipe and set of production equipment data. Many different types of recipe are used in multi-product production lines to produce logic devices, for example. In general, the process control method depends on the recipe. In a conventional process control system, a control program corresponding to the recipe must be developed. Developing programs capable of coping with an increasing number of product types or recipes is very hard. The chief characteristic of the APC system which we have developed is that programs are classified into two distinct types: programs which do not depend on either the recipe or the equipment, and programs which do. Our APC system has already been introduced on trial lines for the following processes in which there has been a large increase in the number of recipes: lithography, reactive ion etching (RIE), chemical dry etching (CDE), wet etching, oxidation, chemical vapor deposition (CVD), sputtering and chemical mechanical polishing (CMP). High-speed implementation of process control programs (up to three recipes per day) has been achieved.