Specific Process Knowledge/Etch/IBE⁄IBSD Ionfab 300/IBE magnetic stack etch

End point detection is achieved by SIMS, and the etch rate is approximately 25 Nm/min. Resist stripping can be hard due to burned resist, to remedy this try to lover the current; this will though chance the sidewall angle. For help, discussion and further info please contact Kristian Hagsted Rasmussen.

Results from the acceptance test in February 2011

Acceptance test for Ti etch:

.	Acceptance Criteria	Acceptance Results
Substrate information	50 mm SSP Si wafer 525 µm thick Supplied by Danchip	.
Material to be etched	E-beam deposited Ti	.
Mask information	E-beam resist mask: 400nm of spin coated ZEP520A e-beam resist Patterned by E-beam lithography	.
Features to be etched	300nm - 3µm dots and lines + a square of 200µmx200µm	.
Etch depth	300nm	~270 nm
Etch rate	>80nm/min	22nm/min +- 0.3nm/min (one standard deviation)
Etch rate uniformity	<+-2%	+-(0.2% +-0.2%)
Reproducibility	<+-2%	+-(0.8% +-0.5%)
Selectivity (Au etch rate/ZEP etch rate)	At least 1:1	0.7:1
Etch profile	70-90dg.	~65dg @270nm ~77dg @123nm

Process parameters for the acceptance test

Parameter	Ti etch acceptance
Neutalizer current [mA]	550
RF Power [W]	1200
Beam current [mA]	500
Beam voltage [V]	600
Beam accelerator voltage	400
Ar flow to neutralizer [sccm]	6.0
Ar flow to beam [sccm]	6.0
Rotation speed [rpm]	20
Stage angle [degrees]	20

Some SEM profile images of the etched Ti

Ti s10-4: 270nm deep - 500nm line. all zep has gone. Profile: ~65 dg.	Ti s10-5: 270nm deep - 300nm line. All zep has gone. Profile: ~65 dg.	Ti S7 5: 123nm deep - 300nm line. Still zep left. Profile: ~77 dg