Lithography equipment transfers circuit or device patterns onto a substrate using a patterned mask and a beam of light or electrons to selectively expose a photo resist layer. Overlay metrology systems align the pattern masks or reticles.
Lithography equipment includes a variety of techniques for transferring circuit patterns to a printed circuit board, such as photolithography, which uses a mask or template, and nanolithography, which uses electron beam imaging to produce a pattern. Another type of lithography process is used to create three dimensional prototypes. Stereolithography creates a three dimensional object based on computer-aided design drawings by tracing a laser beam on the surface of a container of a polymeric substance. The laser beam solidifies the layer which is then submerged in the polymer and another layer is solidified. This process continues until the three dimensional prototype is complete.
Lithography equipment used to create patterns on printed circuit boards and build micro electro mechanical systems (MEMS) include mask aligners, steppers, directing writing tools, and wafer inspection tools. Mask aligners ensure that the photomask is properly aligned on the wafer, steppers are used to transfer the image to the wafer, direct writing tools use laser beams to write directly on a wafer, and wafer inspection tools ensure that the wafer is free from defects. Lithography equipment used for MEMS production include three dimensional machining, dry or wet etching, and electrical discharge machining. Lithography equipment used in micromachining can produce MEMS components for use in accelerometers and inkjet printers, pressure sensors, and optical switches.
Lithography equipment used in nanotechnological applications involves the use of an electron beam to create the mask patterns directly on to a wafer or substrate. The small wavelength used in electron beam imaging (EBI) enables the electron beam to create precise patterns. Electron beam tomography is a medical technology that also uses a rotating electron beam for scanning the body.