US Patent 7717966 Barrier assembly for an exposure apparatus

A barrier assembly (58) for sealing an assembly gap (274) between a first assembly (266) and a second assembly (268) includes a first barrier (270) that seals the assembly gap (274) and a second barrier (272) that seals the assembly gap (274). The barriers (270) (272) can be spaced apart. Further, the first barrier(270) provides a flexible pressure barrier that seals the assembly gap (274) and the second barrier (272) provides a flexible barrier that inhibits the first barrier (270) from contaminating a chamber environment within the assemblies (266) (268). Additionally, the barrier assembly (58) includes a barrier source (62) that controls a barrier environment between the barriers (270) (272).