Alchemy is not dead

I'm working in a field that's related to Semiconductor devices,
some what anyway. It's getting more fascinating to me the
more I think about it.

In anyway, what the semiconductor industry doing is nothing 
short of alchemy. Do you know that the chips you used in your 
pc, handphones, pdas, digital camera are essentially made of sand?

I'm not kidding, they are! Let me briefly bring you through the
process of fabricating a chip.

The raw material is pure silicon, essentially pure sand. The sand
is then melted and allowed to go through a process call
crystallization. This itself could be said as a form of alchemy.
In a way, we can say that we have technology to transform sand
into crystal! Albeit not that type that normal people would perceive.

The Silicon Crystal is grown. 
Yes, grown. It is grown from a full pot of melted Silicon. 
(we call the pot - the crucible). To grow a crystal from
a melted crucible full of silicon, we use a small Silicon crystal called
the seed. With the seed, we could grow a single Silicon ingot.
An ingot is single long round cylinder shaped crystal. Magical isn't it?

Of course, an ingot is too big to make the tiny chips that are found
in our computers and electronics devices. It is first sawed into discs.

Then to gain the electrical property we needed, the crystal disc is
undergone a process called doping. Doping is essentially a process
that add in impurities to the pure Silicon Crystal structure. One of
the impurities element experimented by scientists is gold.
But gold has the nasty habit of diffusing into the Silicon Crystal
and disappear. Well, they don't actually disappear,
but more like changing into silicon. 
So, we have found that we could turn gold into sand!
Well not exactly but close.

Anyhow, by doing this doping process we could make the crystal
more conductive or more resistive to electricity. So, switches could be made
by varying the conductivity and resistivity of different areas of the
crystal disc. These switches then formed the tiny electrical circuits that make our computers and other consumer electronics devices. 
Depending on the process, the chip we wanted to make and the size 
of the Silicon Crystal disc, one disc could be used to make many 
little chips.

So, imagine that, the pc you used to type away and to read this blog is actually run by a device that is made of sand!! Isn't that alchemy?