dear fellow ,
I need to etch an Aluminium gate (0.1um) on GaAs substrates .We know how
to etch
it with a wet process and now we want to do it by RIE
 with Cl2 and BCl3 gas (we had C2F6, SF6, O2,Ar, N2,CHF3 too). The
problem is that Cl2 etches GaAs too.Do you know something about the gas
:
Ratio % ,sccm ;RF power, pressure  to etch Al on GaAs?  BCl3  etch
Al2O3  ,do you think it's possible to oxydize Al on GaAs substrate and
etch Al2O3 after ?
Thanks you for your suggestions


        Arnaud Margolli
        DGA - Celar
        division DIRAC-TECN
        failure analysis -ECE Dep
        + 33  (0)  2 99  42 66 06