Specific Process Knowledge/Lithography/Coaters

From LabAdviser

Coater Comparison Table

Equipment Spin Coater: Gamma UV Spin Coater: Süss Stepper Spin Coater: Gamma E-beam and UV Spin Coater: RCD8 Spin Coater: LabSpin 02 Spin Coater: LabSpin 03 Spin Coater: Manual All Purpose Spray Coater
Purpose
  • In-line substrate HMDS priming
  • Coating and baking of
    • AZ MiR 701 (29cps)
    • AZ nLOF 2020
    • AZ 5214E
  • Coating and baking of
    • BARC (DUV42S-6)
    • KRF M230Y
    • KRF M35G
    • UVN2300-0.8
  • In-line substrate HMDS priming
  • Coating and baking of
    • AR-P 6200 (CSAR)
    • AZ 5214E
    • AZ MiR 701 (29cps)
    • AZ 4562
  • Edge bead removal on novolac-based resist
  • Coating of
    • SU-8
    • AZ 5214E
    • AZ 4562
    • AZ MiR
    • AZ nLOF
  • Edge bead removal
  • Coating of E-beam resists
    • CSAR, ZEP, PMMA/MMA, HSQ(FOx)
  • Coating of UV resists
    • AZ5214E, AZ4562, AZMiR701, AZnLOF, SU-8
  • Coating of imprint resists
  • Coating of
    • ESPACER
    • Experimental resists
  • Coating on
    • Experimental substrates
  • Spraying imprint resist
  • Spraying photoresist
  • Spraying of other solutions
Performance Substrate handling
  • Cassette-to-cassette
  • Vacuum handling and detection
  • Vacuum spin chuck
  • Cassette-to-cassette
  • Vacuum handling and detection
  • Vacuum spin chuck
  • Cassette-to-cassette
  • Vacuum handling and detection
  • Vacuum spin chuck
  • Single substrate
  • Vacuum chuck for 4" and 6"
  • 4" non-vacuum chuck for fragile substrates
  • Single substrate
  • Vacuum chucks for chips, 2", 4", and 6"
  • 4" edge handling chuck
  • Single substrate
  • Vacuum chuck
  • Can handle almost any sample size and shape
Permanent media
  • AZ MiR 701 (29cps) resist
  • AZ nLOF 2020 resist
  • AZ 5214E resist
  • PGMEA solvent for backside rinse and spinner bowl cleaning
  • DUV42S-6 (BARC)
  • KRF M230Y resist
  • KRF M35G resist
  • AR-P 6200.09 (CSAR) for 2", 4", and 6"
  • AZ5214E for 2", 4", and 6"
  • AZ MiR 701 (29cps) for 4", and 6"
  • AZ4562 for 4", and 6"
  • PGMEA solvent for edge bead removal, backside rinse, and spinner bowl cleaning
  • No permanent media
Only manual dispense Only manual dispense
  • No permanent media
Manual dispense option
  • no manual dispense
  • syringe dispense (60cc) of PGMEA-based resist
  • no manual dispense
  • syringe dispense (60cc) of PGMEA and anisole-based resist
  • no manual dispense
  • syringe dispense (30cc) of PGMEA and anisole-based resist (2" only)
  • yes
  • pneumatic dispense for SU-8 resist and EBR solvent
  • Two syringe pumps
Process parameter range Spindle speed
  • 10 - 6000 rpm
  • 10 - 6000 rpm
  • 10 - 6000 rpm
  • 10 - 5000 rpm (3000 rpm with non-vacuum chuck)
  • 100 - 5000 rpm (3000 rpm with edge handling chuck)
  • 100 - 7000 rpm
Gyrset
  • no
  • no
  • no
  • optional (max. speed 3000 rpm)
  • no
  • no
Substrates Substrate size
  • 50 mm wafers (tool change required)
  • 100 mm wafers
  • 150 mm wafers
  • 200 mm wafers (tool change required)
  • 100 mm wafers
  • 150 mm wafers
  • 200 mm wafers (may require tool change)
  • 2" or 50 mm wafers
  • 100 mm wafers
  • 150 mm wafers
  • 100 mm wafer
  • 150 mm wafer
  • 50 mm wafers
  • 100 mm wafers
  • 150 mm wafer
  • small pieces down to 10x10 mm2
  • 50 mm wafers
  • 100 mm wafers
  • 150 mm wafer
  • small pieces down to 3x3 mm2
  • Any sample(s) that fit inside machine
Batch size
  • 1 - 25
  • 1 - 25
  • 1 - 25
  • 1
  • 1
  • 1
  • 1
Allowed materials
  • Silicon
  • Glass

No resist or crystalbond allowed in the HMDS module

  • Silicon
  • Glass
  • Silicon
  • III-V materials
  • Glass

No resist or crystalbond allowed in the HMDS module

  • All cleanroom materials except III-V materials
  • Silicon
  • III-V materials
  • Glass
  • All cleanroom materials
  • All chemicals to be spray coated must be approved specifically for spray coating
  • Any non-toxic, non-particulate and non-crosslinking material is likely to be approved


Spin coating

The process of spin coating consists of a selection of the following steps:

  • Priming (typically HMDS)
  • Acceleration to a low spin speed if dynamic dispense is used
  • Resist dispense (static or dynamic)
  • Resist spreading at low spin speed
  • Spin-off
  • Backside rinse (typically during spin-off)
  • Edge-bead removal
  • Softbake (contact or proximity)


After priming, the wafer is centered on the coater chuck and held in place by vacuum, or in some cases pins. If static dispense is used, the wafer remains static during the ensuing resist dispense. In the case of dynamic dispense, the wafer rotates at low spin speed during the dispense. Using too high spin speed during dispense can cause surface wetting issues, while a too low spin speed causes the resist to flow onto the backside of the wafer. After dispense, a short spin at low spin speed may be used in order to spread the resist over the wafer surface before spin-off.

Spin-off

The spin-off cycle determines the thickness of the resist coating. For a given resist, the thickness is primarily a function of the spin-off speed and the spin-off time, both following an inverse power-law (y=k*x^-a). The acceleration to the spin-off speed also influences the thickness, but the effect is dependent on previous steps. The spin-off is usually a simple spin at one speed, but it may be comprised of several steps at different spin speeds. After spin-off, the wafer is decelerated.

The coated thickness, t, as a function of the spin-off speed, w, follows an inverse power-law, t = k * w-a. The constant, k, is a function of the resist viscosity and solid content, and the spin-off time. The exponent, a, is dependent on solvent evaporation, and is typically ~½ for UV resists. This means that from the thickness t1 achieved at spin speed w1, one can estimate the spin speed w2 needed to achieve thickness t2 using the relation:
t1*w1½ = t2*w2½ => w2 = w1 * t12/t22.
For thick SU-8, however, a is observed to be ~1 (probably due to the low solvent content and/or the formation of skin). In this case, the relation simply becomes:
t1*w1 = t2*w2 => w2 = w1 * t1/t2.

Backside rinse

Dependent on the spin speeds used in the various steps of the spin coating, resist may creep over the edge of the wafer and onto the backside. Also, some resists tend to leave fine strings of resist protruding from the edge of the wafer, or folded onto the backside, an effect sometimes referred to as "cotton candy". This resist will contaminate the softbake hotplate, and thus subsequent wafers with resist. In a backside rinse step, solvent administered through a nozzle to the backside of the wafer while spinning at low or medium spin speed dissolves the resist and washes it away. After the rinse, a short spin at medium spin speed dries the wafer before the softbake. During the backside rinse solvent inevitably creeps onto the front side of the wafer. This effect may be used to dissolve and subsequently remove an edge-bead, but it may also leave the rim of the wafer exposed. As an alternative to backside rinse, a wafer which is left dirty on the backside by the spin coat process may be softbaked in proximity in order to protect the hotplate from contamination. This leaves front side coating intact, but also leaves the backside dirty.

Edge bead

During spin coating, resist builds up at the edge of the wafer due to the change in surface tension at the edge. This phenomenon is called an edge-bead. Dependent on spin coating parameters, the coating may be several times thicker at the edge than in the central area. In a subsequent hard contact exposure step, this edge-bead induces an undesired proximity gap which reduces the lateral resolution, and may even cause the wafer to stick to the mask.

In an edge-bead removal step, solvent administered through a nozzle positioned at the edge of the wafer while spinning at low or medium spin speed dissolves the resist and washes it away. After the removal, a short spin at medium spin speed dries the wafer before the softbake. Dependent on the viscosity (solvent content) of the resist at the point of edge-bead removal, this drying spin may cause the resist to re-flow and create a secondary edge-bead. In some cases, it may be necessary to (partially) softbake the resist before edge-bead removal.

Softbake

After spin coating, the solvent in the resist formulation must be evaporated in a baking step in order to solidify the resist. This softbake can be carried out as a contact bake or a proximity bake. In a contact bake, the wafer is held in close contact to the hotplate surface while resting on shallow bumps only 150µm above the hotplate. In a proximity bake, the wafer is first moved into proximity, e.g. 1mm, of the hotplate surface, then held there (on the lift pins) for the duration of the bake.

Spin coaters at DTU Nanolab

Spin Coater: Gamma UV

Spin Coater: Gamma UV in E-5

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Coater comparison table

Spin Coater: Gamma UV was installed at DTU Nanolab in March 2015. It is a Gamma 2M cluster from Süss MicroTec with spin coating, vapour priming, and baking modules. The system handles 4" and 6" wafers without size conversion, and can be set up to handle 2" or 8".

The coater is equipped with 3 different resists lines:

  • AZ MiR 701
  • AZ nLOF 2020
  • AZ 5214E

and

  • 1 syringe, which can be used for various resists.

The processes that are available on the system are developed by Nanolab. Upon request, it is possible to establish new processes. Use of the syringe requires special training, and would as a starting point require batches in excess of 20 wafers.

Training video

The user manual, quality control procedures and results, user APVs, and contact information can be found in LabManager

Process information

General Process Information

Standard Processes:

Syringe processes

Equipment performance and process related parameters

Purpose
  • HMDS priming
  • Spin coating of PGMEA based UV resists
  • Spin coating of E-beam resists 1)
  • Soft baking
Resist
  • AZ MiR 701 (29cps)
  • AZ nLOF 2020
  • AZ 5214E
  • 60cc syringe dispense
Performance HMDS contact angle

60 - 80°

Coating thickness
  • AZ MiR 701: 1.5-4 µm
  • AZ nLOF 2020: 1.5-5 µm
  • AZ 5214E: 1.5-5 µm
  • AZ 4562: 5-15 µm
Process parameters Priming temperature

120 °C

Spin speed

10 - 6000 rpm

Spin acceleration

10 - 10000 rpm/s

Hotplate temperature

25 - 200 °C

Cool plate temperature

21 °C

Substrates Substrate size
  • 50 mm wafers 1)
  • 100 mm wafers
  • 150 mm wafers
  • 200 mm wafers 1)
Allowed materials

Silicon and glass

No resist or crystalbond allowed in the HMDS module

Batch

1 - 25

1) Requires tool change.


Spin Coater: Gamma E-beam and UV

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Coater comparison table

Spin Coater: Gamma E-beam & UV in E-5

Spin Coater: Gamma E-beam and UV will be installed at DTU Nanolab in June 2017. It is a Gamma 4M cluster from Süss MicroTec with spin coating, vapour priming, and baking modules. The system handles 2", 4", and 6" wafers without size conversion, using two separate coater stations.

The 2" coater station is equipped with 2 different resists lines:

  • AZ 5214E
  • AR-P 6200.09 (CSAR)

and

  • 1 syringe, which can be used for various resists (anisole or PGMEA-based).

The 4"/6" coater station is equipped with 4 different resists lines:

  • AZ 5214E
  • AZ MiR 701
  • AR-P 6200.09 (CSAR)
  • AZ 4562

The processes that are available on the system are developed by Nanolab. Upon request, it is possible to establish new processes. Use of the syringe requires special training, and would as a starting point require batches in excess of 20 wafers.

Training video (for Spin Coater: Gamma UV)

The user manual, quality control procedures and results, user APVs, and contact information can be found in LabManager

Process information

General Process information

Standard Processes:

Syringe Processes

Equipment performance and process related parameters

Purpose
  • HMDS priming
  • Spin coating of anisole based E-beam resists
  • Spin coating of PGMEA based UV resists
  • Soft baking
  • Edge bead removal (CSAR and novolac-based UV resists)
Resist
  • AR-P 6200.09 (CSAR)
  • AZ 5214E
  • AZ MiR 701 (29cps) 4"/6" only
  • AZ 4562 4"/6" only
  • 30cc syringe dispense 2" only
Performance HMDS contact angle

60 - 80° (on Silicon)

Coating thickness
  • AR-P 6200.09 (CSAR): 170-500 nm
  • AZ 5214E: 1.5-5 µm
  • AZ MiR 701: 1.5-4 µm
  • AZ 4562: 5-25 µm
Process parameters Priming temperature

120 °C

Spin speed

10 - 6000 rpm

Spin acceleration

10 - 10000 rpm/s

Hotplate temperature

25 - 200 °C

Cool plate temperature

21 °C

Substrates Substrate size
  • 50 mm wafers
  • 100 mm wafers
  • 150 mm wafers
Allowed materials

Silicon, III-V, and glass

No resist or crystalbond allowed in the HMDS module

Batch

1 - 25


Spin Coater: RCD8

Spin coater: RCD8 is located in C-1

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Coater comparison table

Spin Coater: RCD8 is a model RCD8 T spin coater from Süss MicroTec with a motorized media arm and Gyrset functionality. It's primary purpose is spin coating of SU-8 resist. However, due to the possibility of using a non-vacuum chuck, the spin coater is also suitable for coating of substrates with e.g. textured backsides or membranes.

The user manual, user APV, and contact information can be found in LabManager

Process information

Spin coating

Automatic dispense

Recipes and templates

Processing results

Equipment performance and process related parameters

Purpose
  • Spin coating of SU-8 resists
  • Spin coating of PGMEA based AZ resists
  • Spin coating of wafers with structured backside
  • Edge bead removal
Resist
  • manual dispense
  • automatic dispense from syringe
Performance Coating thickness
  • SU-8 resits: 0.1-200+ µm
  • AZ 5214E: 1.5-3 µm
  • AZ 4562: 8-15 µm
  • AZ MiR 701: 1.5-3 µm
  • AZ nLOF 2020: 2-3.5 µm
Process parameters Spin speed

Vacuum chuck: 10 - 5000 rpm
Non-vacuum chuck: Max. 3000 rpm

Spin acceleration

10 - 3000 rpm/s
Max. 1500 rpm/s with Gyrset

Substrates Substrate size
  • 100 mm wafers
  • 150 mm wafers (vacuum chuck only)
Allowed materials

All cleanroom materials ?

Batch

1


Manual Spin Coaters

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Equipment performance and process related parameters

Purpose Labspin

Spin coating of resist ONLY in dedicated bowlsets

Please do NOT use substances which is not for the dedicated bowlsets

All purpose

Spin coating of dirty substances in All purpose

Process parameters Spin speed
  • Vacuum chuck: 100 - 5000 rpm
  • Edge handling chuck: Max. 3000 rpm
Spin acceleration
  • 200 - 4000 rpm/s
Substrates Substrate size
  • Chips 5x5 mm and up
  • 50 mm wafers
  • 100 mm wafers
  • 150 mm wafers
Allowed materials

All cleanroom materials

Please ONLY use substances which is for the dedicated bowlsets in labspins

Batch

1




Spin Coater: Labspin 02 Spin Coater: Labspin 03 + fumehood 11 Spin Coater: Manual All Purpose
Loacted in wetbench 08 in E-5 Located in wetbench 09 in E-5 Located in fumehood in C-1
LabSpin 6, Süss MicroTec LabSpin 6, Süss MicroTec WS-650, Laurell
LabManager LabManager LabManager


Training video: LabSpin02 + 03

Process information

Spin curves (LabSpin 6): AZ 5214E‎, AZ nLOF 2020, ZEP 520A‎, FOX-15, AZ 4562‎, CSAR 6200