[labnetwork] wet etching InGaAlAs

[McWilliams, Scott]

Hello All,

I'm processing some wafers and need to wet etch layers of InGaAlAs of various compositions (Alx values of x = 0.48 to 0.27).  I pulled a reference from the A.W. Clawson III-V etch reference guide that H3PO4/H202/H20 1:1:10 should etch this material, but it is not etching.  The referenced paper does not provide the etchant temperature.

I suspect that I need to perform a surface etch of some type before etching the InGaAlAs.  We do have the limitation that our current mask is 600 angstroms of silicon nitride, so we may be prohibited from performing  HF containing surface etches.

Does anyone have experience with this material and a recommended surface clean?  Is there a better etchant to use?  Has anyone attempted to dry etch this material with a CH4/H2 process?

Thank you,  Scott
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