Automatically form batch via real time dispatcher for furnace operation in 300 mm fab

Abstract

Nowadays, the automation is the fundamental element of a 300 mm Fab. FOUP transportation, lot dispatching and data processing and other production requirements are integrated by the system. On the other hand, dispatching is getting more and more important due to the complicated process routing and reentry process flow in semiconductor Fab. It is important to optimize the batching size in furnace area, since most of furnace EQP are designed to accommodate up to 100 wafers in 300 mm Fab. In order to fully utilize the furnace, some waiting time is allowed to maximize the batch size. Beside, the furnace dispatching must consider the other issue, such as queue time limit. The pre-clean start time or form batch time must be well controlled to prevent product from queue time over and to keep machine from idle. This work describes an auto forming batch system for furnace operation, which is implemented in the real time dispatching system of PSC FAB 12A. The auto form batch rate is raised up to 85% form Q3 2003 to now. And finally, it has been proved that the auto form batch dispatching system not only improve furnace utilization but also reduces the cycle time between wet and furnace operation. Headings of This work are as follows: (1) introduction, (2) RTD system structure for furnace batch dispatching, (3) batch forming time model and furnace dispatching, (4) result and discussion, and (5) future direction and conclusion.