Aspects of the invention include a method and apparatus for processing a substrate using a multi-chamber processing system (e.g., a cluster tool) adapted to process substrates in one or more batch and/or single substrate processing chambers to increase the system throughput. In one embodiment, a system is configured to perform a substrate processing sequence that contains batch processing chambers only, or batch and single substrate processing chambers, to optimize throughput and minimize processing defects due to exposure to a contaminating environment. In one embodiment, a batch processing chamber is used to increase the system throughput by performing a process recipe step that is disproportionately long compared to other process recipe steps in the substrate processing sequence that are performed on the cluster tool. In another embodiment, two or more batch chambers are used to process multiple substrates using one or more of the disproportionately long processing steps in a processing sequence. Aspects of the invention also include an apparatus and method for delivering a precursor to a processing chamber so that a repeatable ALD or CVD deposition process can be performed.