Replacing silicon monitors with in situ particle monitoring in the GSD200 ion implanter

Silicon monitor wafers are typically used to evaluate the cleanliness of an ion implanter in a production environment. Surface detection methods count particles on these wafers prior to processing. The same surface detection methods are used after implantation on the monitor, with the difference between the two measurements determining the cleanliness of the implant tool. This process may occur several times a day. Special monitor wafers and machine time are required to perform this technique, which provides only a snapshot of the machine´s particulate performance. It may also, on occasion, yield incorrect results that can lead to unnecessary intervention. In-situ particle monitoring, on the other hand, allows real time particle detection without machine downtime, costly monitor wafers and the incorrect data usually associated with surface detection techniques. The High Yield Technology Model 20SX in-situ particle monitor was integrated into the Eaten GSD200 ion implanter and used at the IBM Microelectronics Division semiconductor manufacturing facility in Essex Junction, Vermont, to replace monitor wafers. The paper will discuss the integration of the 20SX sensor into the GSD200 and the characterization work that led to the elimination of silicon monitors