some native oxide!

On Wed, Jul 6, 2011 at 3:00 PM, 胡小东  wrote:

> Hi, all,
>
> While etching  (100) silicon wafers,  most of wafers were etched normally..
> But few of (100) silicon wafers of the same batch were not etched at the
> initial time. It seems that the initial reaction just didn't take place.
>
> Has anyone had this experience?
>
> Thanks!