I have patterned my sample using SPR700 with iline autostep, then I did RIE etching. After I was done with etching, I wanted to remove the photoresist with acetone and Remover PG, but it didn't remove photoresist. Any suggestion how can I remove photoresist completely?
Have you tried either O2 or H2 plasma to remove? And which remover did you try?
Hi,
you could use e.g. Omnicoat as adhesion promotor beneath the resist. This can be diluted (in NMP or DMSO) after the RIE process and you can use it as lift-off layer.
What were the RIE gasses used. Some combinations promote polymer deposition during etch. Good solution is to balance this by the concentration of O2 in the feed gas, Otherwise ashing might an acceptable solution.
Adding a small amount of CF4 to O2 tremendously increases the ashing velocity
1day dip with hot NMP at 1st,
Next to scrub using megasonic showering.
I am not allowed to use O2 plasma (because there is 2D material on substrate (GaAs)).
It is not easy to remove a positive tone photoresist after exposed to plasma shower. The best way to completely remove it is to use O2 plasma(if it has no silicon-based component). Organic solvents like NMP would be effective, but residuals can never be completely removed if you coated it on a polymeric or carbonic material like graphene. If you need a surface with almost no residuals, it is effective to insert a sacrificial layer, for example, PVA which is soluble in water or PMMA soluble in acetone unless it gives damages to your material.
I can not use O2 plasma.
I have used Acetone, Remover PG, Remover 1165 as solvent, but they did not work.
I want completely get rid of any residue of photoresist.
I have used LOR5A as a Sacrificial layer, it was even harder to remove that one.
My etch recipe is:
BCL3 : 12 sccm
Ar: 47 sccm
power : 100 W
Voltage: 250 V
Pressure : 25 mTorr
Time : 1min
You probably hardened the resist by the reactive ion etch process meaning you have created a hard carbon-like layer which is very difficult to remove by solvents (and sometimes O2 as well). Since you can not use O2 plasma, I would also go for a double layer as proposed by Mr. Hauser (omnicoat). I have very good experience with LOR (lift-of reist). This is first spun and baked and then the resist layer is applied. During develop the LOR will undercut the normal resist layer and is never exposed to the directional plasma. After the RIE etch the LOR acts as a lift-off layer and you don't have to change your RIE etch process.
LOR is commercial available, so is the solvent which undercuts/lifts the LOR/resist combination.
I don't know how H2 plasma will help, could you please clarify for me? Thanks a lot
H2 plasma will often remove organic films, through formation of volatile species.
A couple links below. I found several articles with google.
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwj2nruNldXMAhUBmR4KHdHtDn8QFgghMAA&url=http%3A%2F%2Fwww.kps.or.kr%2Fjkps%2FdownloadPdf.asp%3Farticleuid%3D%257B58C6DE62-2B76-4609-AAA8-3DAF666D4322%257D&usg=AFQjCNG8morPI3WRBVuTb07qwgCryip6Vw&sig2=yjiZh8Q--R2yu7yG8y0O9w&bvm=bv.121658157,d.dmo
h.physics.asu.edu%2Fsites%2Fdefault%2Ffiles%2Fpublications%2Fsavades%2F179%2520%2520Hydrogen%2520Plasma%2520Removal%2520of%2520Post%2520RIE%2520Residue%2520for%2520Backend%2520Processing.pdf&usg=AFQjCNHTdJ_KiwfmBngYhXJB-1iv7dzerw&sig2=Ndlnc2PcAmXcHhLI2JO4tw&bvm=bv.121658157,d.dmo
We developed process with Oxygen plasma combined with forming gas and fluorine gas in a remote plasma reactor with good results.
Technology is called "HDRF" for High Density Radical Flux.
It's pure chemical etch based on O*, F* and H*.
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