Specific Process Knowledge/Etch/Etching of Silicon Oxide/SiO2 etch using AOE/Standard recipe with resist mask
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Revision as of 11:17, 24 November 2015 by Bghe (talk | contribs) (→Etch rates in different materials using the standard "Silicon oxide etch with resist mask")
The standard recipe
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 | Recipe name: SiO2_res (SiO2 etch with resist mask) | Variations over SiO2_res made in 2010 by BGHE |
---|---|---|
Coil Power [W] | 1300 | 1000-1600 |
Platen Power [W] | 200 | 150-300 |
Platen temperature [oC] | 0 | 0 |
He flow [sccm] | 174 | 174, 300 |
C4F8 flow [sccm] | 5 | 5 |
H2 flow [sccm] | 4 | 0, 4 |
Pressure [mTorr] | 4 | 2.3, 4 |
Etch rates in different materials using the standard "Silicon oxide etch with resist mask"
Material to be etched | Etch rate using SiO2_res | |
---|---|---|
Thermal oxide | ~230nm/min (5% etch load) - etch load dependency see here | |
TEOS oxide (5% load) | 233nm/min ±0.7% - "±" represents the non-uniformity over a 100mm wafer - etched in Marts 2013 by LN/BGE@danchip | |
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 | |
Al2O3 from the ALD | 50nm can be etched in 10min - etched in November 2014 by FRSTO@danchip | |
Silicon rich nitride from furnace B2 | 136nm was etched in 1min (whole wafer) - etched in October 2015 by bghe@danchip |
Using different resist masks: results using the standard recipe for "Silicon oxide etch with resist mask"
. | Az | MIR | nLof | KRF | CSAR |
---|---|---|---|---|---|
Selectivity to thermal oxide [:1] |
|
1.8 - tested November 2015 by BGHE | 2.0 - tested November 2015 by BGHE | ~2 - tested May 2013 by Christian Østergaard @nanotech. | . |
Profile [o] | ~90 | . | . | . | . |
Roughness of the resist after etch - striation on sidewalls | . | . | . | . | . |
Images | See here | . | . | See images here | . |
Comments | A negative resist process was done to make the mask. I have not had so good results with a positive resist process. | . | . | . | 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 |
Striation: Side wall roughness
Variations over the standard "SiO2 etch with resist mask" recipe
Typical results | Variations over SiO2_res made in 2010 by BGHE See results here |
---|---|
Etch rate of thermal oxide | ~160-340nm/min |
Selectivity to AZ resist [:1] | 2.7-4.3 |
Profile angle | 83-90 |
Images | See here |
Comments | . |
Etching of micro structures in Aluminum oxide
by Fredrik Stöhr
Aluminum oxide (Al2O3, Alumina) can be etched with the standard recipe for silicon oxide etching. The parameters including the chuck temperature are identical to the recipe described above: SiO2_res. The etch is probably very physical and gives redeposition, so please consider using a Cl2 etch on the ICP metal instead (BGHE 2015-04-17)
General Description
- Process date: Summer 2014
- Aluminum Oxide with a thickness of 50 nm has been deposited by atomic layer deposition using the respective standard recipe.
- Substrates: Blank 525 µm Silicon wafers or Silicon wafers with thermally grown Silicon Oxide prior to Alumina deposition.
- Mask: [XOP8] AZ5214E 1.5 µm thick (HMDS pretreatment, 6-inch aligner 3 sec exposure, 60 sec development).
- Etch Load (Total Exposed SiO2): ~ 5 %
- Post process: O2 Plasma Ashing 10 min