A load lock chamber is an auxillary chamber attached to a process chamber usually with a gate valve between the chambers. It has its own high vacuum pumping system and venting. It typically contains a sample holder that can hold a number of individual samples and a mechanical transfer mechanism to move samples to and from the process chamber. A load lock chamber is used when a user wants to reduce the cycle time of processing samples and reducing the potential for contamination in the process chamber. Samples are loaded into the load lock chamber while at atmosphere. The load lock chamber is then pumped down to a high vacuum pressure. The gate valve is then opened between the load lock chamber and the process chamber. One or more samples are then mechanically transferred between the chambers by means of the linear transfer mechanism. After the samples are processed they are transferred back to the load lock chamber. During this process the process chamber is always under vacuum. A load lock allows samples to be transferred into the process chamber without venting the chamber to atmosphere.