Specific Process Knowledge/Etch/AOE (Advanced Oxide Etch)/Silicon Nitride Etch using AOE

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Silicon nitride etch with the standard silicon oxide etch

The standard recipe for oxide etching with photo resist as masking material is called: SiO2_res. It can also be used for nitride etching- The parameters and results so fare are as follows:

Parameter	Recipe name: SiO2_res (SiO2 etch with resist mask)
Coil Power [W]	1300
Platen Power [W]	200
Platen temperature [oC]	0
He flow [sccm]	174
C4F8 flow [sccm]	5
H2 flow [sccm]	4
Pressure [mTorr]	4

Typical results	Test Results	Variations over SiO2_res made in 2010 by BGHE See results here
Etch rate of thermal oxide	~230nm/min (5% etch load) - etch load dependency see here	~160-340nm/min
Selectivity to AZ resist [:1]	~3 - etch load dependency [[Specific Process Knowledge/Etch/AOE (Advanced Oxide Etch)/Silicon Nitride Etch using AOE/AOE SiO2 etch load dependency|see here]|	2.7-4.3
Selectivity to DUV resist [:1]	~2.0 - tested May 2013 by Christian Østergaard @nanotech.	?
Profile [o]	~90	83-90
Images	See here	See here
Comments	A negative resist process was done to make the mask. I have not had so good results with a positive resist process.
Etch rate of TEOS oxide (5% load)	233nm/min ±0.7% - "±" represents the non-uniformity over a 100mm wafer - etched in Marts 2013 by LN/BGE@danchip
Etch rate of PECVD1 (standard) oxide (5% load)	242nm/min ±0.6% - "±" represents the non-uniformity over a 100mm wafer - etched in Marts 2013 by LN/BGE@danchip
Etch rate of Al2O from the ALD	50nm can be etched in 10min - etched in November 2014 by FRSTO@danchip
Etch rate of Silicon rich nitride from furnace B2	136nm was etched in 1min (whole wafer) - etched in October 2015 by bghe@danchip
Etch of SiO2 with DUV mask	See images here

Test of etch in silicon nitride (LPCVD). 105nm nitride had to be removed - it was removed after 1min and 40s with a very small over etch in Si.

Parameter	Recipe name: Nitr_res (Silicon Nitride etch using resist mask)
Coil Power [W]	700
Platen Power [W]	100
Platen temperature [oC]	0
C$_{4}$F$_{8}$ flow [sccm]	5
He flow [sccm]	174
H$_{2}$ flow [sccm]	4
Pressure [mTorr]	4

Typical results	Resist mask	Resist mask
Silicon nitride (LPCVD) etch rate	~60 nm/min	99-108 nm/min (LN/BGE 20130512)
Selectivity to photo resist [:1]	?	~between 2.5 and 4.0 (LN/BGE 20130512)
Etch rate in Si	?	?
Etch rate in SiO2	?	?
Profile [o]	not tested	not tested
Etch uniforminty over a wafer [o]	not tested	± 1.1% to ±1.8% (Eric Jensen @nanotech, oct. 2013)
Images	.	.
Comments	.	.