Jump to content

Specific Process Knowledge/Lithography/UVExposure/aligner MLA2

From LabAdviser

Aligner: Maskless 02

 
Aligner: Maskless 02 is located in E-5.

Tool description
The MLA2 is a UV exposure tool, which can be used for direct writing of digital mask designs, on photosensitive resists on chips, 50 mm, 100 mm, 150 mm and 200 mm substrates.

Product: Heidelberg Instruments MLA150 WM I Maskless Aligner
Year of purchase: 2018
Tool modification: Modified from WM1 to WM2 in 2023
Location: Cleanroom E-5

Features

  • Optical Autofocus
  • Pneumatic Autofocus
  • Top side Alignment
  • Back side Alignment
  • Gray Scale Exposure
  • Advanced Field Alignment Mode for alignment to individual chips/devices on the substrate
  • High Aspect Ratio Mode for exposure of thick resists
  • 200 x 200 mm exposure field

User manual
The user manual and contact information can be found in LabManager - requires login

Tool training
Training on the tool requires users to complete the lithography TPT followed by the online tool training and a hands-on authorization training.

Equipment performance and process related parameters

Purpose Alignment and UV exposure
Exposure modes Projection
Exposure light/filters 375 nm (laser diode array)
Dynamic focusing method
  • Optical
  • Pneumatic
Minimum resolution ~1 µm
Design file formats
  • GDS-II
  • CIF
  • DXF
  • Gerber
  • HIMT format
Alignment modes
  • Top side (TSA): ±0.5 µm
  • Back side (TSA): ±1 µm
  • Advanced field alignment (chip-by-chip TSA): ±0.25 µm
Substrate size
  • Maximum writing area: 200 mm x 200 mm
  • Small pieces: 3 mm x 3 mm with optical autofocus
  • 50 mm wafers
  • 100 mm wafers
  • 150 mm wafers
  • 200 mm wafers
Allowed materials
  • All cleanroom allowed materials
  • Total height variation across the substrate must be less than ±90 µm - including wafer bow
Substrate batch 1

Process information

Exposure dose

Information on UV exposure dose

Alignment mark design and locations

Alignment mark design and locations.

Quality Control (QC)

The purpose of the QC process is to check the optical performance and alignment accuracy of the maskless aligners. The optical performance is checked by making a dose/defocus test. The alignment accuracy is checked by making a global alignment test for both topside alignment and back side alignment.

Dose/defoc limit:
Deviations in the optical performance are not easily corrected, and is likely due to contaminated or damaged writehead. If either the dose or defoc changes, the tool is investigated for writehead contamination and/or damage.

Alignment accuracy accept limit:
Must be within machine specifications, and should be adjusted if necessary. The top side alignment accuracy for MLA2 is ±0.5 µm. The backside alignment accuracy for MLA2 is ±1 µm.

Documentation: