Abstract: A workpiece handling system with dual load locks, a transport chamber and a process chamber. Workpieces may be retrieved from one load lock for processing at vacuum pressure, while workpieces are unloaded from the other load lock at the pressure of the surrounding environment. The transport chamber has a transport robot with two arms. Processed workpieces and new workpieces may be exchanged by a simple under/over motion of the two robot arms. The transport robot rotates about a central shaft to align with the load locks or the process chamber. The robot may also be raised or lowered to align the arms with the desired location to which workpieces are deposited or from which workpieces are retrieved. The two load locks may be positioned one above the other such that a simple vertical motion of the robot can be used to select between the two load locks. The two load locks and transport robot allow almost continuous processing.

Abstract: A workpiece handling system with dual load locks, a transport chamber and a process chamber. Workpieces may be retrieved from one load lock for processing at vacuum pressure, while workpieces are unloaded from the other load lock at the pressure of the surrounding environment. The transport chamber has a transport robot with two arms. Processed workpieces and new workpieces may be exchanged by a simple under/over motion of the two robot arms. The transport robot rotates about a central shaft to align with the load locks or the process chamber. The robot may also be raised or lowered to align the arms with the desired location to which workpieces are deposited or from which workpieces are retrieved. The two load locks may be positioned one above the other such that a simple vertical motion of the robot can be used to select between the two load locks. The two load locks and transport robot allow almost continuous processing.

Abstract: A workpiece handling system with dual load locks, a transport chamber and a process chamber. Workpieces may be retrieved from one load lock for processing at vacuum pressure, while workpieces are unloaded from the other load lock at the pressure of the surrounding environment. The transport chamber has a transport robot with two arms. Processed workpieces and new workpieces may be exchanged by a simple under/over motion of the two robot arms. The transport robot rotates about a central shaft to align with the load locks or the process chamber. The robot may also be raised or lowered to align the arms with the desired location to which workpieces are deposited or from which workpieces are retrieved. The two load locks may be positioned one above the other such that a simple vertical motion of the robot can be used to select between the two load locks. The two load locks and transport robot allow almost continuous processing.

Abstract: A workpiece handling system with dual load locks, a transport chamber and a process chamber. Workpieces may be retrieved from one load lock for processing at vacuum pressure, while workpieces are unloaded from the other load lock at the pressure of the surrounding envirornment. The transport chamber has a transport robot with two arms. Processed workpieces and new workpieces may be exchanged by a simple under/over motion of the two robot arms. The transport robot rotates about a central shaft to align with the load locks or the process chamber. The robot may also be raised or lowered to align the arms with the desired location to which workpieces are deposited or from which workpieces are retrieved. The two load locks may be positioned one above the other such that a simple vertical motion of the robot can be used to select between the two load locks. The two load locks and transport robot allow almost continuous processing.

Abstract: In order to compensate for worn or distorted wafer cassettes and missing wafers, the cassette of wafers is scanned through a beam. The timing of the interruptions of the beam is used to inventory the wafers present and measure the exact position of each wafer relative to the base of the cassette.

Abstract: A wafer processing system including wafer handling arms incorporated into vacuum isolation valves is described. A loadlock with elevator and optical sensors is used to inventory and position a cassette of wafers. The wafers in the cassette can be randomly accessed. A computer is used to control the system according to a task status table independent of time sequence.