Buffers are temporary wafer storage locations inside processing tools to optimize wafer flow and tool utilization. Purpose: Decouple wafer feeding from processing, enable parallel operations, store wafers during recipe changes or tool recovery. Location: Within EFEM, transfer chamber, or dedicated buffer modules. Capacity: Few wafers (2-10 typical) - not long-term storage. Use cases: Hold next wafer ready while current processes, store wafers during chamber conditioning, queue wafers for multi-chamber tools. Cooling stations: Some buffers include cooling for post-process wafer cooldown before returning to FOUP. Environment: Match environment (vacuum, N2, clean air) to adjacent areas. Management: Tool controller optimizes buffer usage for throughput. Pre-heating: Some tools use buffer stations for wafer pre-heating before process. Mechanical design: Slots or pedestals for wafer storage. Minimal contact design. Throughput impact: Buffers reduce idle time - robot can fetch next wafer while process runs.