| 摘要 |
A cluster system controls the interface properties of the films that deposit or grow on a silicon substrate. The system comprises a plurality of horizontal quartz chamber or tubes each of which can hold a large quantity of wafers, a transfer chamber and a load/unload chamber. Several process steps can be executed sequentially in different tubes without intermediate exposure to ambient air. A transfer chamber connects them and allows wafer transportation from one tube to another in an absolute controlled UHV environment which limits any contamination such as H2O, to less than a monolayer level. In addition, each tube can be pumped down to UHV pressure regime to avoid further cross contamination between tubes or particle generation. Since some of the process requires elevated temperature, all wafers are placed vertically on the quartz boat to prevent any wafer sagging as in a vertical furnace. Furthermore, before any wafers are placed into the transfer chamber, they are loaded into a load/unload chamber, which is the sole connection to the ambient air, to be purged and pumped so as to minimize particles and contamination.
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