Specific Process Knowledge/Etch/ICP Metal Etcher

The ICP Metal Etcher in short

Despite its name the metal etcher doesn't etch metals in general. Currently, the list of metals that you can etch is quite short:

• aluminium
• titanium
• chromium

Over time it is our intention to add other materials to the list such as molybdenum, tungsten, titaniumtungsten, titaniumoxides or piezo-materials such as ZnO. However, currently you are not even allowed to expose other metals to the plasma.

Etching of nanostructures in silicon using the ICP Metal Etcher or DRIE Pegasus

• The 180 nm zep resist profiles (Wafer WF_2B1_feb06_2011)
• The 340 nm zep resist profiles (Wafer WF_2C1_feb2011)
• The 211 nm zep resist profiles (Wafer WF_2E02_mar23_2011)

Recipe Sinano	3.0	3.1	3.2	3.3	3.4	4.0	3.5	3.6	3.3	3.7	3.31	3.31	3.32
Cl2 (sccm)	0	0	0	0	0	20	15	15	0	0	0	0	0
BCl3 (sccm)	5	3	5	5	5	0	5	5	5	5	5	5	5
HBr (sccm)	15	17	15	15	15	0	0	0	15	15	15	15	15
Coil power (W)	900 L	900 F	900 F	900 F	900 F	900 L	900 L	900 F	900 F	900 L	900 F	900 F	900 F
Platen power (W)	50	50	60	75	90	60	60	60	75	60	75	75	30
Pressure (mtorr)	2	2	2	2	2	2	5	10	2	10	2	2	2
Temperature (oC)	20	20	20	20	20	20	20	20	20	50	50	50	50
Spacers (mm)	100	100	100	100	100	100	100	100	100	100	100	30	100
Process time (s)	150	180	120	180	120	90	120	180	300	180	180	180	180
Etch rates (nm/min)
Averages	311	104	92	105	116	169	108	79	101	66	91	98	59
Std. Dev	44	15	15	21	22	9	11	31	29	4	28	18	12
Zep etch rate (nm/min)
		30	40	51	67			45	59		53	36	19
Sidewall angle (degrees)
Averages	82	82	82	82	82	84	81	83	83	85	80	83	79
Std. Dev	2	2	1	1	1	1	1	2	2	1	3	2	2
CD loss (nm pr edge)
Averages	65	-11	-15	-2	-11	67	63	-29	-5	-29	10	-14	-17
Std. Dev	30	5	2	4	3	29	27	6	5	8	7	8	10
Bowing (nm)
Averages	31	31	15	6	5	22	12	15	28	13	25	1	-2
Std. Dev	6	7	3	6	4	5	2	6	9	7	5	2	2
Botton curvature
Averages	-9	-6	-9	-11	-9	9	-4	-8	-24	-2	-9	-13	-10
Std. Dev	22	19	19	11	7	17	15	15	12	15	13	17	18

• Nanoetch on DRIE-Pegasus
• 1 - the first nanoetch