Specific Process Knowledge/Etch/DRIE-Pegasus/processB

From LabAdviser
Process B specifications
Parameter Specification Average result
Etch rate (µm/min) > 10 10.7
Etched depth (µm) 100 107
Scallop size (nm) < 800 685
Profile (degs) 91 +/- 1 90.7
Selectivity to AZ photoresist > 100 183
Undercut (µm) <1.5 0.89
Uniformity (%) < 3.5 3.0
Repeatability (%) <4 0.47



Process B recipe
Step 1 Step 2
Parameter Etch Dep Etch Dep
Gas flow (sccm) SF6 350 (1.5 s) 550 C4F8 200 SF6 350 (1.5 s) 550 C4F8 200
Cycle time (secs) 7.0 4.0 7.0 4.0
Pressure (mtorr) 25 (1.5 s) 90 >> 150 25 25 (1.5 s) 150 25
Coil power (W) 2800 2000 2800 2000
Platen power (W) 120 >> 140 (1.5) 45 0 140 (1.5) 45 0
Cycles 11 (keep fixed) 44 (vary this)
Common Temperature 20 degs, HBC 10 torr, Short funnel, with baffle & 5mm spacers