The Heidelberg maskless aligner (MLA150) is a direct write lithography tool with high writing speeds and easy operation. It allows the user to directly pattern photoresists without the need for photomasks; CAD files are written directly into the resist. When design changes are needed, the CAD files only need to be adjusted and the file is ready to be used for the next exposure. There is no waiting for new photomasks. The MLA150 does not physically contact the substrate. It uses a micro-mirror array to expose the pattern only in the desired locations. Photoresists for g-, h-, and i-line exposure can be used with the system and a low-quality exposure mode can reduce exposure times.
The system has additional features not typically found in mask aligners. It can automatically add labeling and serialization information to designs. When using structures with random locations, the software’s Draw Mode allows exposures to be drawn on a real-time view of the substrate from the system’s camera. For situations where three dimensional patterns are needed in the photoresist, the MLA150’s grayscale capability can be used.
Light source: diode lasers: 8 W at 405 nm and 2.8W at 375 nm
Substrate sizes: 5 mm x 5 mm to 228 mm x 228 mm
Maximum exposure area: 200 mm x 200 mm
Minimum feature size: 1 um (isolated line)
Alignment: front-side and back-side alignment
Front-side alignment accuracy: < 0.5 um
Back-side alignment accuracy: < 1 um
Grayscale: 128 levels
CAD input formats: gdsii, dxf, cif, gerber