Hi
I very much agree wtih the suggestion made by MIchael Pedersen, that
instead of raising the temperature you should try to increase the
conctration. you should also try to use a Al with some percentage of
silicon in it, so that i already satisfies the solid solubility limit.
this is required to take care of spiking.
regds
Ravi Shankar
Semiconductor Complex ltd
India



On Thu, 25 Apr 2002, Michael Pedersen wrote:

> Sandra,
> I would not necessarily worry about diffusion through the wafer. The
> more important problem is the "spiking" effect that may occur when Al
> diffuses in silicon, which will affect the quality of the contact. I
> think you would better off if you could raise the doping of the silicon
> by other means (ion implantation/boron/phosphorus diffusion).
>
> MIchael Pedersen
> MEMS Exchange
>
> Sandra Bermejo wrote:
>
> > Dear Ravi,
> > Thanks for your answer,
> > I usually make an anneal in H2N2 ambient for 20 minutes. The temperature
> > ranges from 450:C to 500:C. I wonder if I can raise this temperature
avoiding
> > the diffusion of aluminium trough the wafer.
> > Best regards,
> > Sandra
> >
> > Ravi Shankar ha escrito:
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