To whomever it may concern,
 1. how do we measure the oxide thickness other than the color charts
. are there any oxide thickness devices which are cheap and accurate
to give the results.
 2.after diffusion i need to develop a 3.6um oxide layer only on front
side as an etch mask by CVD. But we dont have a CVD process what is
the other way of developing such thickness.
 I can't do it in an oxidation furnace because it takes place at high
temperatures and i can start diffusing the p type doping.
I knew a spin on glass thing but the maximum oxide thickness that i
can get by spin on glass is 0.5um

 3. In diffusion furnace how is the doping takes place. I knew some
there are liquid and solid dopants. which are the best to use and also
send information on companies that do them.
 4. where can i get N-type(100) silicon 1-10ohm-cm, of 200 um thick
 can anyone please e-mail the details of the information including the
companies that make them.
 Thanking you,
 Amith