Aligner: Maskless 03

Tool description
The MLA3 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 and 150 mm substrates. It is possible to load a 200 mm wafer, but the writable area is only 150 mm x 150 mm.

Product:	Heidelberg Instruments MLA150 WM II Maskless Aligner
Year of purchase:	2019
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	405 nm (laser diode array)
Dynamic focusing method	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: 150 mm x 150 mm Small pieces: 5 mm x 5 mm 50 mm wafers 100 mm wafers 150 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 MLA3 is ±0.5 µm. The backside alignment accuracy for MLA3 is ±1 µm.

Documentation:

The QC procedure for Aligner: MLA3 - requires login
The newest QC data for Aligner: MLA3 - requires login