Specific Process Knowledge/Lithography/UVExposure/aligner MLA2

Aligner: Maskless 02

MLA150 WMII maskless aligner from Heidelberg Instruments GmbH (installed 2019 as WMI (0.6µm resolution), rebuilt to WMII 2023).

Special features

Optical Autofocus
Backside Alignment
Basic 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
Separate conversion PC

Link to information about alignment mark design.

Equipment info in LabManager - requires login

Quality Control (QC) for Aligner: Maskless 02 (MLA2) - Dose and Defoc

QC Recipe:	Dose and defocus test on 1.5µm AZ5214E
Dose test	Last QC value ± 20 mJ/cm² (9 steps total)
Defoc test	Last QC value ± 8 (9 steps total)

QC limits	Aligner: Maskless 02 (MLA2)
Dose	none
Defoc	none

Dose and defoc values are reported in the QC data sheet.

Quality Control (QC) for Aligner: Maskless 02 (MLA2) - Alignment

QC Recipe:	Alignment accuracy test
Topside alignment	Expose an overlay design after automatic alignment to 4 alignment marks using the High Res camera and applying scaling and shearing. Alignment accuracy in 9 points across a 100mm wafer is measured, the average alignment error is reported.
Backside alignment	Expose an overlay design after automatic alignment to 4 backside alignment marks and applying scaling and shearing. Rotate the wafer 180° and repeat. Alignment accuracy in 9 points across a 100mm wafer is measured, half the average alignment error is reported.

QC limits	Aligner: Maskless 02 (MLA2)
Topside alignment error	>0.5µm
Backside alignment error	>1µm

Camera offsets will be adjusted if alignment error is outside the limit.

Purpose		Alignment and UV exposure
Performance	Exposure mode	Projection
	Exposure light	375 nm (laser diode arrays)
	Focusing method	Optical Pneumatic
	Minimum structure size	down to 1 µm
	Design formats	GDS-II CIF DXF Gerber HIMT format
	Alignment modes	Top side alignment, ±0.5µm Backside alignment, ±1.0µm Field alignment (chip-by-chip TSA), ±0.25µm (within 5x5mm² area)
Substrates	Substrate size	maximum writing area: 200x200 mm² 200 mm wafer 150 mm wafer 100 mm wafer 50 mm wafer pieces down to 3x3 mm² ¹⁾
	Allowed materials	All cleanroom materials Total height variation across the substrate must be less than ±90 µm - including wafer bow
	Batch	1

¹⁾ with optical autofocus