Specific Process Knowledge/Lithography/CSAR

These tests are currently in progress and this page thus under construction. If you have questions to the process or wish to use this e-beam resist, please contact Tine Greibe at tigre@danchip.dtu.dk.

Process Flow

Test of Chemically Semi-Amplified Resist (CSAR); a positive e-beam resist from AllResist (AR-P 6200-2).

Equipment	Process Parameters	Comments
Pretreatment
4" Si wafers	No Pretreatment
Spin Coat
Spin Coater Manual, LabSpin, A-5	AR-P 6200/2 AllResist E-beam resist 60 sec at various spin speed. Acceleration 4000 s-2, softbake 1 - 5 min at 150 deg Celcius	Disposal pipette used; clean by N2-gun before use. Use approximately 1.5 ml per 4" wafer, never use a pipette twice. Softbake is not a crucial step, see e-mail correspondence with AllResist here.
Characterization
Ellipsometer VASE B-1	9 points measured on 100 mm wafer	ZEP program used; measured at 70 deg only
E-beam Exposure
JEOL 9500 E-beam writer, E-1	Dosepattern 15nm - 100nm, dose 120-280 muC/cm2	Virtual chip mark height detection (CHIPAL V1) used in corner of every dose array
Development
Fumehood, D-3	60 sec in X AR 600-54/6, 60 sec rinse in IPA, N2 Blow dry	Gentle agitation while developing. After developing, wafer is immersed in beaker with IPA, subsequently blow dried with N2 gun.
Characterization
Zeiss SEM Supra 60VP, D-3	2 kV, shortest working distance possible, chip mounted with Al tape	Before characterization, wafers were sputter coated with 2-3 nm Pt at DTU CEN.

Spin Curves

The thickness is measured on VASE Ellipsometer using a simple Cauchy model for a transparent polymer on Si. The measurements are performed at one incidence angle (70 degrees) only. 9 points on each 4" wafer has been measured; the standard deviation thus representing the homogeinity of the film on the 4" wafers.

AllResist AR-P 6200/2 spinning on Spin Coater: Manual LabSpin A-5, TIGRE, 09-04-2014. Softbake 5 min @ 150 degC.
Spin Speed [rpm]	Acceleration [1/s2]	Thickness [nm]	St Dev
2000	4000	225.98	0.97
3000	4000	194.00	0.6
4000	4000	169.57	0.32
5000	4000	151.47	0.26
6000	4000	142.38	0.41
7000	4000	126.59	0.36

AllResist CSAR on Spin Coater: Manual LabSpin A-5, TIGRE, 16-06-2014. Softbake 2 min @ 150 degC.
Spin Speed [rpm]	Acceleration [1/s2]	Thickness [nm]	St Dev
3000	4000	201.61	1.20
4000	4000	173.89	0.64
5000	4000	155.91	0.65

AllResist CSAR 1:1 in anisole, Spin Coater: Manual LabSpin A-5, TIGRE, 16-06-2014. Softbake 2 min @ 150 degC.
Spin Speed [rpm]	Acceleration [1/s2]	Thickness [nm]	St Dev
2000	4000	83.48	0.49
3000	4000	67.12	0.41
4000	4000	58.64	0.44
5000	4000	53.13	0.39
6000	4000	48.76	0.38

SEM pictures

The wafers are diced into smaller pieces and sputter coated with Pt at DTU CEN before SEM inspection; please contact Valentina Mateiu for further information.

50nm

dose [muC/cm2]	207	219	230	242

30nm

dose [muC/cm2]	207	219	230	242