Hi,

    Can you explain the purpose of the dry-wet-dry oxidation steps? If this is
for some gate oxide, does it show comparable results to a plain dry oxide of
similar thickness?

One thing I might try is to do an initial solvent, BOE, RCA1 (and RCA2 depending
on if metal contamination would affect your results), BOE clean.

Best of luck.

Felix

On Jan 22, 2012, at 3:02 AM, H V Balachandra Achar wrote:

> Dear All,
>
> I am using 1 micron thick thermal oxide, grown using dry-wet-dry sequence, as
> the mask during bulk etching of silicon using KOH solution. After oxidation I
> notice pin holes in oxide surface. Because of these pin holes, silicon is
> getting etched in KOH at places where I don't want to etch.
>
> Please suggest a remedy.
>
> Note: I am using (100) p-type 1-10 ohm-cm Si wafer.
> Cleaning sequence: TCE, acetone, nitric acid, dilute HF
> Dry-wet-dry durations: 20 min - 4 hrs - 20 min, followed by 30 min annealing
> in N2 ambient.
>
> Thank you
>
> --
> H V Balachandra Achar

----------------------------
Felix Lu
felix_lu@yahoo.com