Specific Process Knowledge/Etch/DRIE-Pegasus/nanoetch/nano12

The nano1.2 recipe

Recipe nano1.2

Recipe	Gas	C4F8 38 sccm, SF6 52 sccm
	Pressure	4 mTorr, Strike 3 secs @ 15 mTorr
	Power	800 W CP, 50 W PP
	Temperature	-10 degs
	Hardware	100 mm Spacers
	Time	120 secs
Conditions	Run ID	1817
	Conditioning	Sequence: Oxygen clean, MU tests, processes, no oxygen between runs
	Mask	343 nm zep etched down to 154 nm

• The results of the nano1.2 recipe
• 
  The 30 nm trenches
• 
  The 60 nm trenches
• 
  The 90 nm trenches
• 
  The 120 nm trenches
• 
  The 150 nm trenches
• File:C4F8 52 sccm, SF6 38 sccm, 4 mTorr, Strike 3 secs @ 15 mTorr, 800 W CP, 50 W PP, -10 degs, 120 secs

Nominal trench line width	'	30	60	90	120	150	Avg	Std
Etch rates	nm/min	241	285	307	325	335	299	37
Sidewall angle	degs	92	92	92	91	91	92	0
CD loss	nm/edge	-5	-8	-18	-18	-34	-17	11
CD loss foot	nm/edge	-5	-8	-18	-18	-4	-10	7
Bowing		19	11	11	14	10	13	4
Curvature		-48	-46	-43	-40	-40	-44	4
Zep etch rate	nm/min						95

Comments

Lower temperature certainly looks like a step in the right direction. Confirms that the process was too etch aggressive previously, hence the isotropic profiles.