Hi,

Gas jet assisted laser drilling could be an option.  We got good quality
burr free holes of 30 micron drilled in alumina substrate using a CO2
laser.

Good Luck,

-Ashutosh Shastry-

================================================================================
        Ashutosh Shastry                Research Associate,
        #30, Vihar House, IIT,          Microelectronics Group,
        Powai, MUMBAI, INDIA-76.        EE Department,
        Phone: 091-22-5721791           I.I.T. Bombay, INDIA 400 076.
        Email: shastrys@vsnl.com        Phone:091-22-5723655
===============================================================================
        O Traveller, there is no such thing as PATH...
                                        .....paths are MADE by walking.
================================================================================


On Mon, 4 Dec 2000, Tim E. Harper wrote:

Hi,

We have some sapphire wafers which we need to modify by producing  'holes'
somewhere around 50 microns diameter, 200 microns deep. We need a fairly
urgent solution to this, but we have a constraint that because of other
devices on the wafer we would want to keep the temperature as low as
possible.

We tried FIB, but the milling rate is too slow to be practical. Does anyone
have any idea
a)      if there is a better method for etching sapphire?
b)      Is there a lab in Europe who could help us?

Regards

Tim


*****************************************************************
Tim E. Harper                    Managing Director
CMP Cientifica s.l.
Space & NanoTechnology Division
Phone +34 91 640 71 85       Fax  +34 91 640 71 86
http://www.cmp-cientifica.com/