| 主权项 |
1. A method of handling a workpiece, comprising:
transferring a workpiece from a load port to a rotatable platform in a load lock; capturing an image of the workpiece near an entrance to said load lock during said transferring; determining from said image an orientation of the workpiece relative to a frame of reference; pumping down a pressure within said load lock from an ambient pressure to a reactor chamber pressure; during said pumping down, rotating said rotatable platform to change the orientation of said workpiece to a desired orientation; after said pumping down, transporting said workpiece from said rotatable platform of said load lock to a processing chamber; determining from said image a location of a center of said workpiece relative to said frame of reference; and during said transferring, aligning the center of said workpiece with a center of said rotatable platform; wherein said load lock comprises a first vacuum sealable door, and a second vacuum sealable door openable to the processing chamber; wherein said transferring follows a workpiece transfer path through an opening of said first vacuum sealable door and said transporting follows a workpiece transfer path through an opening of said second vacuum sealable door; closing said first vacuum sealable door upon completion of said transferring and prior to said pumping down; and opening said second vacuum sealable door upon completion of said pumping down; determining from said image a defect measurement corresponding to a defect count or defect density; and if said defect measurement exceeds a predetermined threshold, withdrawing said workpiece away from said load lock prior to closing said first vacuum sealable door. |
