Value Added Solutions Eliminated Need for Parallel System
The ultrapure water (UPW) capacity of the clients’ flagship wafer fab was upgraded by adding equipment to nearly every unit operation in the plant, instead of adding a costly parallel plant.
The driver for the project was a steadily increasing demand on UPW driven by fab buildout and a different manufacturing equipment set than originally envisioned for the fab. This systematic, stepwise project began with an analysis of the UPW system capabilities. Starting with the design information from the existing system and then individually analyzing each piece of equipment associated with each step of the process, Farnsworth Group determined the capacity constraints both from a process perspective and a hydraulic viewpoint. We then worked alongside the client to arrive at the best estimate of the future fab requirements in light of current realities. The gap between the existing system capacity and the future fab requirements needed to be closed to support upcoming operations in this expanding fab.
The gap was greater than could be supported by simply adding equipment in the existing trains and was ultimately constrained by piping capacity. It was initially thought that a complete parallel UPW system, including a building to house it, would have to be built to support the increased demand, but Farnsworth Group identified and proposed several innovative methods to reduce the polish system requirements without increasing risk to the fab, while still meeting all tool demands. With these value engineering solutions, the gap was reduced to the point where upgrades within the existing plant were feasible.
Farnsworth Group went on to lead the detailed design efforts for a two-phase implementation of capacity upgrades to support the near term and full build out demands of the fab.
Other notable details include:
- Innovative distribution pressure controls reducing polish requirement by 400 gpm
- Replacement of ultrafilters with high performance cartridge filters, saving water and maintaining the fab particle spec
- Replacement of vacuum degasifier tower with gas transfer membranes, resolving a key bottleneck