Patent ID: 7135691

Claim:
A reciprocating drive system for scanning a workpiece through an ion beam, the reciprocating drive system comprising: a process chamber associated with the ion beam; a motor operably coupled to the process chamber, the motor comprising a rotor and a stator, wherein the rotor and the stator are operable to individually rotate about a first axis, wherein an electromagnetic force between the rotor and the stator generally determines a rotational position of the rotor about the first axis, and wherein the stator is operable to act as a reaction mass to the rotation of the rotor; a shaft fixedly coupled to the rotor, wherein the shaft extends along the first axis into the process chamber; a scan arm generally residing within the process chamber and operably coupled to the shaft, wherein the scan arm comprises an end effector operable to support the workpiece thereon, and wherein the rotational position of the rotor generally determines a position of the workpiece with respect to the ion beam along a first scan path; and a controller operable to control the position of the workpiece along the first scan path by controlling the electromagnetic force between the rotor and the stator.