Maskless Aligner (Heidelberg MLA150)

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Maskless Aligner (Heidelberg MLA150)
MLA150 Heidelberg Bay 6 Photo.jpg
Tool Type Lithography
Location Bay 6
Supervisor Biljana Stamenic
Supervisor Phone (805) 893-4002
Supervisor E-Mail
Description Direct-Write (Maskless) I-Line Photolithography
Manufacturer Heidelberg Instruments
Model MLA150
Materials I-Line Photoresists
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The MLA150 allows for arbitrary direct-write patterning of I-Line photoresists from an uploaded CAD drawing/file (GDS, DXF, CIF etc.). The system uses a digital micromirror device ("DMD", an array of MEMS mirrors) for patterning the exposure light-field, to programmatically expose digitized patterns directly onto the sample - no glass photomasks/reticles are required.

Depending on the exposure options and write area, the MLA is able to expose a 100mm wafer in about 30min, and achieves minimum features sizes around 0.5µm, with overlay/alignment accuracy better than 200nm.

The system has a continuous, automatic autofocus, using pneumatic and optical detection. This potentially enables lithography on non-planar or curved substrates.

The software allows for custom drawings and aligment marks to be exposed onto any feature located on the microscope.

Greyscale lithography allows for photoresist profiles with repeatable slanted or tapered structures, via an 8-bit greyscale bitmap or layer-structured DXF file.

The high-aspect ratio (variable/long focal length) option enables vertical sidewalls on very thick (~100µm) photoresists.

Schematic of spatial light modulator exposure technique.
Exposure method using a spatial light modulator, continuously moving stage and continuous autofocus. See HIMT for more info.

Detailed Specifications

  • Maximum Writeable Area: 150 x 150mm
  • Substrate size: 9-inch square or 200mm round down to 5-mm pieces
    • Contact staff for pieces < 5 mm.
  • Wafer / substrate thickness: Max. 9mm / Min. 0.1mm
  • Exposure optics:
  • Alignment Accuracy: Global ≤ 500nm; Local ("Field") ≤ 250nm
  • Linewidth variation: ≤100nm (relevant to stitched exposure fields)
  • Write Grid (Address Unit):
    • High Quality Mode (std.): 40nm
    • Fast Mode: 100nm
  • Additional manufacturer options:
    • High-resolution option (Write Mode 1)
    • Extended Focus Range
    • Variable Focal Depth
    • Optical (laser) Autofocus in addition to std. Pneumatic Autofocus
    • Greyscale Mode
    • (No backside alignment)


Operating Procedures

Troubleshooting & Known Bugs

    • See the above page for troubleshooting/recovery info and workarounds to known bugs.

Video Trainings

Important: You must be authorized by a supervisor to use the tool!  The video below is provided for reference only, and does not substitute training by NanoFab  staff. Contact the Supervisor for authorization.

Design Tools/Info