The standard recipe for oxide etching with photo resist as masking material is called: SiO2_res. The parameters and results so fare are as follows:
Parameter
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Recipe name: SiO2_res (SiO2 etch with resist mask)
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Variations over SiO2_res made in 2010 by BGHE
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Coil Power [W]
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1300
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1000-1600
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Platen Power [W]
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200
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150-300
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Platen temperature [oC]
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0
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0
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He flow [sccm]
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174
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174, 300
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C4F8 flow [sccm]
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5
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5
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H2 flow [sccm]
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4
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0, 4
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Pressure [mTorr]
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4
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2.3, 4
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Etch rates in different materials using the standard "Silicon oxide etch with resist mask"
Material to be etched
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Etch rate using SiO2_res
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Thermal oxide
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~230nm/min (5% etch load) - etch load dependency see here
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TEOS oxide (5% load)
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233nm/min ±0.7% - "±" represents the non-uniformity over a 100mm wafer - etched in Marts 2013 by LN/BGE@danchip
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PECVD1 (standard) oxide (5% load)
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242nm/min ±0.6% - "±" represents the non-uniformity over a 100mm wafer - etched in Marts 2013 by LN/BGE@danchip
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Al2O from the ALD
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50nm can be etched in 10min - etched in November 2014 by FRSTO@danchip
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Silicon rich nitride from furnace B2
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136nm was etched in 1min (whole wafer) - etched in October 2015 by bghe@danchip
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Using different resist masks: results using the standard recipe for "Silicon oxide etch with resist mask"
.
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Az
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MIR
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nLof
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KRF
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CSAR
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Selectivity to thermal oxide [:1]
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- 2-3 - etch load dependency see here
- 1.9 - tested November 2015 by BGHE
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1.8 - tested November 2015 by BGHE
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2.0 - tested November 2015 by BGHE
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~2 - tested May 2013 by Christian Østergaard @nanotech.
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.
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Profile [o]
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~90
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.
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.
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.
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.
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Roughness of the resist after etch - striation on sidewalls
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.
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.
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.
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.
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.
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Images
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See here
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.
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.
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See images here
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.
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Comments
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A negative resist process was done to make the mask. I have not had so good results with a positive resist process.
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.
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.
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.
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Using the standard oxide recipe (SiO2_res) for 1 min the CSAR looked burned and could not be removed by CSAR stripper (AR600-71). For a better recipe look here
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Striation: Side wall roughness
- Striation with different resists used
Az resist - profile after etch
Mir resist - profile after etch
nLof resist - profile after etch