Development and application of a new tool for lithographic mask evaluation, the stepper equivalent Aerial Image Measurement System, AIMS

Two carriage systems, X and Y, are provided with the X carriage system being carried by the Y carriage system. Each system includes a carriage which via two sets of rollers is capable of movement along a guide rail set. Flex hinges are provided in each carriage to seat the rollers in the guide rails. The hinges are generally rigid in a first plane and flexible in a second such that the carriage is stiff yet the distance between the rollers can vary to compensate for absolute distance changes in the rails, due, for example, to high or low spots in the roller contacting surface.