Atlas 46 – novel negative tone photoresist which combinesthe good properties of the established SU-8 and CAR 44

EIPBN, 30th Mai 2018

Dr. Christian Kaiser, Matthias SchirmerAllresist GmbH, Germany

Outline

• Short Introduction of Allresist GmbH

• Well-established CAR 44 for i-line and g-line

• Motivation/ Goal

• New development Atlas S and Atlas R

• PAG-variation to ensure h-line and g-line sensitivity

• 3D structures by variation of photoacid generator (PAG)

• 3D structures via double imprint lithography (University of Wuppertal)

• Fluorescent Atlas 46 S layers

206.06.2018

Short Introduction of Allresist GmbH

06.06.2018 3

• Founded 16th October in 1992, located in Strausberg, Germany

• Quality management system ISO 9001:2008 and ISO 14001:2004

• Since 2006 on the way of business of excellence

• Global player with competent support (> 50 % export)

• Full equipment of resist characterization and modern analytic methodes

• Intense scientific cooperations with universities, institutes and industrial partners

• 32 scientific projects completed successfully

• Customer specific, taylor-made resists, short lead times

Turbine wheel produced with AR-N 4400-50, thickness: 100 µm via double coating

3 µm resolution, pattern with AR-N 4400-10,thickness: 15 µm

Benefits

• High sensitivity, excellent resolution

• Suitable for g-line and X-ray as well

• Excellent properties for galvanic applications, vertical profiles, easy to remove

• Good plasma etching stability

Drawbacks

• Compared to SU-8 lower stability

• Highest single layer up to 50 µm, SU-8: 200 µm

Well-established CAR 44 for i-line and g-line

06.06.2018

Vertical profiles, AR-N 4400-50, thickness: 55 µm

Art work, pattern with AR-N 4400-10

Motivation / Goal

06.06.2018 5

• CAR 44 is a high quality negative resist but stability is insufficient for some applications

• Limitation of well-known SU-8: difficult to remove, low sensitivity at i-line

• Creating a resist with good properties similar to SU-8 with higher sensitivty at i-line and easy to remove

• Herein we like to present different versions of new Atlas 46:

– AR-N 4600-10 (Atlas 46 S) – properties very similar to SU-8 (plug&play resist)

– AR-N 4650-10 (Atlas 46 R) – removable resist version (e.g. for galvanic applications)

– SX AR-N 4610-10/1 – version with significantly enhanced sensitivity at i-line

– SX AR-N 4620-10/1 – h/g-line sensitive (e.g. for two-layer applications)

New development: Atlas 46 S / Atlas 46 R

• Suitable for applications with layers which need to remain permanently & resistively on substrate

• Sensitivity (broad band UV) 120 mJ/cm²

• Depending on exposure dosage and PEB individually adjustable removability

• Sensitivity (broad band UV) 140 mJ/cm²

• Resist thicknesses: 5 µm up to 200 µm (single coating step, temperature ramp recommended for thicker layers)

• Tg: 35°C – 45°C, thermal stability (cross-linked): up to 300°C

• Developers for Atlas 46 S; strong: AR 600-70, weak: AR 300-12

• Developers for Atlas 46 R; strong: AR 300-12, weak: AR 600-0706.06.2018

New development: Atlas 46 S and Atlas 46 R

Resist thickness vs. solid content

06.06.2018

Atlas 46 R: 100 s exposure, 5 min @ 95 °C PEB hotplate, 60 s AR 300-12 (university of Halle)

Atlas 46 S: 40 s exposure, 5 min @ 95 °C PEB hotplate, 60 s AR 300-12, (university of Halle)

• Correlation between film thickness and solid content comparable to SU-8

• Well-defined line pattern with vertical walls

PAG-variation to ensure h-line and g-line sensitivity

PAG4 in SX AR-N 4620-10/1 for h-/g-line sensitivityRed line: SX AR-N 4610-10/1, enhanced i-line sensitivity (PAG3)Blue line: mercury lamp spectra

• Atlas S/R and SU-8 relative low sensitivity at i-line (365nm)

• New PAG’s suitable to enhance sensitivity at i-line: SX AR-N 4610-10/1

• PAG 4, for the first time h-/g-line (405 nm/436 nm) sensitivity established

• SX AR-N 4620-10/1 provides access to new applications for 3d-patterning

06.06.2018 8

9

3D structures by variation of PAG

06.06.2018

General process:

First results for 2-layer system trenches; bottom: AR-N 4600-10, top: SX AR-N 4610-10/1 (i-line sensitive)

• Atlas 46 S on bottom, SX AR-N 4610-10/1 or SX AR-N 4620-10/1 on top

• No significant intermixing between the different resists

• Combination of different resist versions allows generation of 3d architectures (e.g. bridged structures)

First results for 2-layer system, trenches; bottom: SX AR-N 4600-10, top: SX AR-N 4620-10/1 (h-line / g-line sensitive)

substrate substrate substrate substrate

Coating layer 1,Soft bake

Exposure 1

Cross-linking (PEB)Coating layer 2,Soft bake

development

substrate

Exposure 2

Cross-linking (PEB)

1006.06.2018[2] C. Steinberg; M. Rumler; M. Runkel; M. Papenheim, S. Wang, A. Mayer; M. Becker; M. Rommel; H.-C. Scheer, Microelectronic Engineering, 2017, 176, 22-27

[1] C. Steinberg; M. Papenheim; S. Wang; H.-C. Scheer, Microelectronic Engineering, 2016, 155, 14-18

3D structures via double imprint lithography (University of Wuppertal)

Comparison NIL properties of SU-8, Atlas 46 S and CAR 44

- Double imprint lithography allowed a combination of nano- and micro structures

- Requirement of different chemically amplified photoresists for pre-preparation of hierarchical structures: hardened nanostructures are most stable during second imprint

- Comparable nanostructure stability between SU-8 and Atlas 46 S

- Insufficient thermal stability with CAR 44

Process sequence suitable for different negative photoresists:

a) definition of nano-structures in a negative tone photoresist via thermal imprintb) surface-near VUV flood exposure of the pre-patterned surfacec) second imprint with microstructures

Fluorescent Atlas 46 S layers

06.06.2018 11

Different fluorescence of the AR-Logo & lines (Atlas 46 S)

Different fluorescent layers of Atlas 46 S

• Various brilliant fluorescence dyes embedded in polymer matrix

• Suitable for photo resists (Atlas 46 S) and as well for ebeam resists (PMMA, CSAR 62)

• Lithographic application allow generation of fluorescent pattern (e.g. for microscopy)

• Multi-layer process for combination of different dyed architectures: overlapping or adjacent pattern

• Two different path ways:

a) combination of ATLAS 46 versions optimized for different exposure wavelengths

b) processing bottom layer (spin coating, exposure, PEB and development) following by patterning a top resist showing a different fluorescence

06.06.2018 12

Many thanks for your attention!