The content on this page, including all images and pictures, was created by DTU Nanolab staff, unless otherwise stated.

Feedback to this page: click here

Mask Aligner vs Maskless Aligner

Slides presented at NNUM in Uppsala 2026: MA6 vs MLA 2026_v09

Mask design used in the investigation: LithoTestAlign_2025_v10.gds

Data from the investigation

THIS PAGE IS UNDER CONSTRUCTION

AZ 5214E

Resolution

Resolution at optimal processing conditions for 1.5µm AZ 5214E using different exposure equipment:


Exposure equipment	Dose [mJ/cm²]	Contact/Defoc	Resolution [µm]	Comment
Aligner: MA6-2	100	Vacuum	1
Aligner: MA6-1	100	Vacuum	1.25	Probably over-exposed
Aligner: Maskless 02 (MLA2)	90	2	1.25

SEM images from different exposure equipment for 1.5µm AZ 5214E at optimal processing conditions:

	2µm triplets	Lines	Trenches
Aligner: MA6-2 100mJ/cm², vacuum contact
Aligner: MA6-1 100mJ/cm², vacuum contact (probably over-exposed)
Aligner: Maskless 02 (MLA2) 90mJ/cm², defoc 2

SEM images of different size structures for 1.5µm AZ 5214E:

	1µm triplets	2µm triplets	4µm triplets
Aligner: MA6-1 100mJ/cm², vacuum contact (probably over-exposed)

Yield

The yield is measured by inspecting all 116 lithographic resolution test structures in an optical microscope and recording the smallest resolved dots and lines.

**Wafer maps for 1.5µm AZ 5214E at optimal processing conditions for different aligners**


Aligner: Maskless 02 (MLA2) (Dose 90mJ/cm²; defoc 2). Resolution: 1.22µm average; 0.1µm standard deviation. Yield at 1.25µm: 99%	Aligner: MA6-2 (Dose 100mJ/cm²; vacuum contact). Resolution: 1.02µm average; 0.1µm standard deviation. Yield at 1.25µm: 100%	Aligner: MA6-1 (Dose 100mJ/cm²; vacuum contact). Probably over-exposed. Resolution: 1.30µm average; 0.2µm standard deviation. Yield at 1.25µm: 59%

Effect of exposure mode for mask aligner

**Wafer maps for 1.5µm AZ 5214E at different exposure modes for Aligner: MA6-2 (Dose 100mJ/cm²)**


Hard contact. Resolution: 1.17µm average; 0.2µm standard deviation. Yield at 1.25µm: 89%	Soft contact. Resolution: 3.77µm average; 0.7µm standard deviation. Yield at 2.5µm: 4%	10µm proximity. Resolution: 4.19µm average; 0.7µm standard deviation. Yield at 2.5µm: 3%

**Wafer maps for 1.5µm AZ 5214E at different exposure modes for Aligner: MA6-1 (Dose 100mJ/cm², probably over-exposed)**


Hard contact. Resolution: 1.58µm average; 0.5µm standard deviation. Yield at 1.25µm: 48%	Soft contact. Resolution: 2.36µm average; 0.4µm standard deviation. Yield at 2.5µm: 80% At dose 92mJ/cm², the average resolution decreases to 1.91µm and the yield at 2.5µm increases to 100%	10µm proximity. Resolution: 2.73µm average; 0.6µm standard deviation. Yield at 2.5µm: 53%

Effect of WEC pressure for mask aligner (after WEC head service)

**Wafer maps for 1.5µm AZ 5214E at different WEC pressure for Aligner: MA6-2 (Dose 100mJ/cm²)**


Soft contact, 0.15bar WEC pressure. Resolution: 3.92µm average; 0.9µm standard deviation. Yield at 2.5µm: 8%	Soft contact, 0.40bar WEC pressure. Resolution: 2.19µm average; 0.5µm standard deviation. Yield at 2.5µm: 86%

10µm proximity, 0.15bar WEC pressure. Resolution: 3.22µm average; 0.8µm standard deviation. Yield at 2.5µm: 34%	10µm proximity, 0.40bar WEC pressure. Resolution: 2.83µm average; 0.6µm standard deviation. Yield at 2.5µm: 66%

Resist profile

Linewidth and sidewall angle vs exposure dose

SEM images of 1.5µm AZ 5214E as a function of exposure dose for Aligner: MA6-2 using vacuum contact:

	85mJ/cm²	90mJ/cm²	95mJ/cm²	100mJ/cm²	105mJ/cm²
2µm triplets
Lines

SEM images of 1.5µm AZ 5214E as a function of exposure dose for Aligner: Maskless 02 (MLA2) using defoc 2:

	80mJ/cm²	90mJ/cm²	100mJ/cm²	110mJ/cm²
2µm triplets
Trenches and Lines

Result of image analysis of SEM images of 2µm triplets:




Width of 2µm line and sidewall angle vs. exposure dose for 1.5µm AZ 5214E. Blue circles: Exposed on Aligner: MA6-2 in vacuum contact. Orange Squares: Exposed on Aligner: Maskless 02 (MLA2) using defoc 2 (QC defoc=2).

Linewidth and sidewall angle vs defocus parameter

SEM images of 1.5µm AZ 5214E as a function of defocus parameter for Aligner: Maskless 02 (MLA2) using dose 95mJ/cm²:

	Defoc -8	Defoc -1	Defoc 2	Defoc 5	Defoc 12
2µm triplets
Lines

Result of image analysis of SEM images of 2µm triplets:




Linewidth and sidewall angle vs. defocus value for 1.5µm AZ 5214E exposed in Aligner: Maskless 02 (MLA2) using dose 95mJ/cm². Blue circles: Width of 2µm line. Orange Squares: Sidewall angle.

AZ MiR 701

Resolution

Table with optimal parameters and resolution for different aligners
SEM pictures

Resolution at optimal processing conditions for 1.5µm AZ MiR 701 using different exposure equipment:


Exposure equipment	Dose [mJ/cm²]	Contact/Defoc	Resolution [µm]	Comment
Aligner: MA6-2	220	Vacuum	1
Aligner: Maskless 02 (MLA2)	275	2	1

SEM images of 1.5µm AZ MiR 701 from different exposure equipment at optimal processing conditions:

	2µm triplets	Lines	Trenches
Aligner: MA6-2 220mJ/cm², vacuum contact
Aligner: Maskless 02 (MLA2) 275mJ/cm², defoc 2

Resist profile (sidewall angle and linewidth)

SEM pictures to support graphs?

Result of image analysis of SEM images of 2µm triplets:




Width of 2µm line and sidewall angle vs. exposure dose for 1.5µm AZ MiR 701. Blue circles: Exposed on Aligner: MA6-2 in vacuum contact. Orange Squares: Exposed on Aligner: Maskless 02 (MLA2) using defoc 2 (QC defoc=2).

Result of image analysis of SEM images of 2µm triplets:




Linewidth and sidewall angle vs. defocus value for 1.5µm AZ MiR 701 exposed in Aligner: Maskless 02 (MLA2) using dose 95mJ/cm². Blue circles: Width of 2µm line. Orange Squares: Sidewall angle.

AZ nLOF 2020

Resolution

Resolution at optimal processing conditions for 2µm AZ nLOF 2020 using different exposure equipment:


Exposure equipment	Dose [mJ/cm²]	Contact/Defoc	Resolution [µm]
Aligner: MA6-2	154	Vacuum	1
Aligner: Maskless 01 (MLA1)	220	-4	2
Aligner: Maskless 02 (MLA2)	450	0	1.25

SEM images of 2µm AZ nLOF 2020 from different exposure equipment at optimal processing conditions:

	2µm triplets	Lines	Trenches
Aligner: MA6-2 154mJ/cm², vacuum contact	File:W07 MA6 nLOF D154 vac C8T 01.jpg	File:W07 MA6 nLOF D154 vac C8T ??.jpg	File:W07 MA6 nLOF D154 vac C8T ??.jpg
Aligner: Maskless 01 (MLA1) 220mJ/cm², Defoc -4	File:W06 MLA1 nLOF D220 F-4 01.jpg	File:W06 MLA1 nLOF D220 F-4 ??.jpg	File:W06 MLA1 nLOF D220 F-4 ??.jpg
Aligner: Maskless 02 (MLA2) 450mJ/cm², defoc 0	File:W17 mla2 nLOF D450 F0 04.jpg	File:W17 mla2 nLOF D450 F0 ??.jpg	File:W17 mla2 nLOF D450 F0 ??.jpg

SEM images of different size structures for 2µm AZ nLOF 2020:

	1µm triplets	2µm triplets	4µm triplets
Aligner: MA6-2 154mJ/cm², vacuum contact	File:W07 MA6 nLOF D154 vac C8T 05.jpg	File:W07 MA6 nLOF D154 vac C8T 01.jpg	File:W07 MA6 nLOF D154 vac C8T 02.jpg
Aligner: Maskless 01 (MLA1) 220mJ/cm², Defoc -4	File:W06 MLA1 nLOF D220 F-4 02.jpg	File:W06 MLA1 nLOF D220 F-4 01.jpg	File:W06 MLA1 nLOF D220 F-4 03.jpg

Cross-sectional SEM images of 2µm AZ nLOF 2020 at optimal processing conditions:

	2µm lines	2µm trenches	Lines	Trenches
Aligner: Maskless 01 (MLA1) 220mJ/cm², Defoc -4	File:W04 mla1 nLOF D220 F-4 X l 2um.jpg	File:W04 mla1 nLOF D220 F-4 X t 2um.jpg	File:W04 mla1 nLOF D220 F-4 Xlines.jpg	File:W04 mla1 nLOF D220 F-4 Xtrench.jpg

Resist profile (sidewall angle and linewidth)

SEM pictures to support graphs?

Result of image analysis of SEM images of 2µm triplets:




Sidewall angle vs. exposure dose for 2µm AZ nLOF 2020. Blue circles: Exposed on Aligner: MA6-2 in vacuum contact. Orange Squares: Exposed on Aligner: Maskless 01 (MLA1) using defoc -4 (QC defoc=-2). Grey triangles: Exposed on Aligner: Maskless 02 (MLA2) using defoc 0 (QC defoc=2).

Result of image analysis of SEM images of 2µm triplets:




Linewidth and sidewall angle vs. defocus value for 2µm AZ nLOF exposed in Aligner: Maskless 01 (MLA1) using dose 220mJ/cm² and Aligner: Maskless 02 (MLA2) using dose 450mJ/cm², respectively. Blue circles: Width of 2µm line. Orange Squares: Sidewall angle.