Patent ID: 8104752

Claim:
A compound positioning system where a first positioning stage is rotatably mounted on top of a second positioning stage for use in providing submicron translation errors for large substrates, said compound positioning system comprising: a base having a generally flat top surface extending in an X direction and a Y direction; one or more air bearing pucks, said one or more air bearing pucks bearing upon said top surface of said base and being displaced therefrom by an air gap; a plate being movably supported by said one or more air bearing pucks with said plate thereby being free to move in the X and Y directions and being free to rotate; a first positioning stage, said first positioning stage comprising: a linear rail being fixed to said top surface of said base and being oriented in the Y direction; a puck being slidably mounted to said linear rail; and a linear motor to drive said slidable puck along said Y-direction linear rail; a second positioning stage, said second positioning stage comprising: a linear rail mounted to said plate and being oriented in the X direction; a puck being slidably mounted to said X-direction linear rail; and a linear motor to drive said puck along said X-direction linear rail; said second positioning stage being mounted on top of said first positioning stage forming said compound positioning system; said second positioning stage being mounted on top of said first positioning stage by a rotary bearing being fixed to both said X-direction puck and to said Y-direction puck to permit a ⊖-rotation angle between said plate and said base, said rotation being driven by a rotary motor; and wherein said movement of said moveable plate is simultaneously corrected during movement for inaccuracies in the X and Y directions, and for θ rotational errors, and wherein said one or more air bearing pucks provide XY-plane support for said movable plate to maintain submicron Z-direction accuracy.