For the best process control in the foundry, the operators must understand the technology that controls each step of the process. In addition, operators must test and control all important variables of the system. The time has long past when one can just test everything and hope for the best. Neither time nor money is available to do everything.
So how does the engineer or operator decide what the important variables are? The simplest answer is to test the system and let the data give us the answer. But where do we start and how much testing is needed?
The most data with the least amount of testing is obtained by a technique called DOE, or design of experiment. The technique has been around for many years, over 50 for sure. This paper will describe some of the past applications of DOE and discuss the technique for use in the foundry.