Michael,

Nice to get a III-V question now and then.
AlGaAs is a funny material to etch.  If you have any leaks in your chamber
you will grow a dark material believed to be aluminum oxide that stops the
etch.
We have found BCl3 (2 sccm) with Ar (8 sccm) at 20 watts and less than 10
mT
works well for us (we are etching 70% AlGaAs) and is not affected by system
leaks.
AlGaAs less than 15% should etch with Cl2/Ar but roughness is always an
issue with Cl2.

Hope this helps,

Brent

Michael Juhl wrote:

> Hi,
>
>
>
> I need to do a RIE etch in a AlGaAs/GaAs material using Cl2/Ar. I will
> have to etch in depths of about 50nm with etch rates about 30 nm/min.
>
>
>
> If someone has information about recipes that works well with this
> technology please let me know.
>
>
>
> The recipe that I use at the moment is 40 W rf power, 10 mTorr, 3 sccm
> Cl2, 40 sccm Ar. I have problems with surface roughness and unstable
> etching rates.
>
>
>
> Best regards,
>
> Michael Juhl
>
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