durusmail: mems-talk: Re: Aluminum safe Si etching.
Re: Aluminum safe Si etching.
1997-06-27
Re: Aluminum safe Si etching.
Alexander Holke
1997-06-27
>
> Hello,
>       I am trying to find an anisotropic silicon etchant which also
> doesn't attack Aluminum.
>
> I was told that TMAH doesnot attack Al. I tried etching under the
> following conditions.
>
> Concentration - TMAH 25% - rest water.
> Temperature - 80C and also at 100C.
>
> The Aluminum was removed under less than 15 mins. I would like any
> information from about the etch conditions and also any other etchant
> suitable for the purpose.
>
> Thank You in advance,
>
> Nandakumar.
>
>
> --
> K.Nandakumar.                                  Tel : (216) 368 4109 (Lab)
> 2504, Derbyshire Rd, #2,                             (216) 371 6746 (res)
> Cleveland, OH 44106.                           Fax:  (216) 368 2668.
>
>

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I recall a paper where Al attack decreased considerably when Si was
etched and going into the TMAH solution.

Also hydrazide does not attack Al.

Make sure that your Al does not contain Al, which it usually does for
Si metalization to prevent spiking.


Alexander Hoelke
University of Cincinnati
CMSM


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