Collecting silicon wafers

From: Dave Wilson <davol_at_globalnet.co.uk>
Date: Thu Mar 13 15:05:01 2003

> On Wed, 12 Mar 2003, Sridhar wrote:
>
> An extremely new wafer can be valuable just by the ability to reverse
> newfangled engineering.
>
> Peace... Sridhar

Can't see this myself. Yes. I know it's theoretically possible (just)
Modern chips are to all intents and purposes three dimensional objects.
The real logic lies, out of sight below several layers of metal conductor.
It's just this, incidentally, that makes them of limited interest to a
collector. (There's not much to see on the surface anymore)
So OK, you could probe them with X-rays or something like that or try
etching away the layers with acids.
My own view is that this is just about as impossible a task as one can
possibly imagine. After you've done all of this you'd have to reverse
your way back to the masks (which, these days, are quite distinct from
the geometries they produce on silicon. AND THEN you have to have a
fabrication available to you that is capable of putting the whole thing
back together again. Much easier just to steal the design database.

The forward engineering is quite difficult enough. It's my own belief
that reverse engineering is - practically speaking - intractable.

If this really is so appealing to sinister governments etc. why not
just reverse engineer the chip they bought legitimately, by mail order.

  
> On Tue, 11 Mar 2003, Chandra Bajpai wrote:
>
> > Before anyone goes in trying to cash in their wafers...I assume any
> > wafer that was not kept in a clean room environment is worthless. The
> > couple of wafers I have finger prints so they definitely are worthless!

I'd respectfully suggest that the concept of value is not quite as
straightforward as you suggest, Chandra. How much would your two wafers
be worth if I were willing to buy them off you? Postage stamps are just
about as 'worthless' as anyone could imagine, yet I'm regularly sent
catalogues offering stamps at prices that amount to more than my annual
salary.
Received on Thu Mar 13 2003 - 15:05:01 GMT