A method and apparatus for a modular processing system is described. The apparatus includes a transfer chamber as the foundation for the system and includes sidewalls adapted to receive at least three 200 mm and/or 300 mm process chambers. The transfer chamber includes a robot capable of withstanding high temperatures and is configured to transfer 200 mm and 300 mm substrates. The modularity of the transfer chamber is highly transportable and provides a research and development platform at a low cost of ownership and may be modularly built into a production system as additional chambers and peripheral hardware is added.