Overview of Optical Lithography in MEMS / MST

摘要

The presentation reviews the requirements of optical lithography in MEMS/MST. Therntypes of lithography considered are:rn- Reduction Steppersrn- 1X Steppersrn- Projection Alignersrn- Contact Printersrn- Direct Write LaserrnThe lithography techniques are compared using key parameters that typically definernprocess requirements. These are:rnImaging:rn- Critical Dimension (CD)rn- CD size controlrn- Usable Depth of Focusrn- Field sizesrnAlignment:rn- Front (or Top) side Alignment accuracyrn- Double sided aligment performancern- Alignment with necessary Focus offsets for topographyrn- IR alignmentrnSubsequently a segmentation of the MEMS/MST devices is made on the basis of thernphysics of their functionality, and their functionality (actuator, transducer, passive).rnBased on the overview of the optical litho parameters and the segmentation of the devicerntypes given above, the devices types from the segmentation are classified to the processrnrequirements of the manufacturing of these devices. For a selection of these devicesrnspecific details will be discussed. The aim of this presentation is twofold:rn- It can serve as a guide for MEMS/MST manufacturers to choose the appropriaternlithography tool for the manufacture of their devices.