Hi Sonia,

When placing the wafers vertically I had the problem of the shadows behind the
structures due to the flow of the bubbles, so I ended putting the wafers
horizontally at about 3 cm from the bottom of the bath. I used a holder for
this. The face to be etched was put upwards. I had to use a stirring speed quite
high to make sure there was succesful removal of bubbles in the top face. I
didn't try putting the wafer upside-down.

Best regards,

Pablo.

Pablo de la Fuente Prado
pdlfuente@ceit.es

-----Original Message-----
From: GARCIA BLANCO Sonia [mailto:Sonia.Garcia.Blanco@ino.ca]
Sent: 14 November 2005 15:08
To: 'General MEMS discussion'
Cc: de la Fuente, Pablo
Subject: RE: [mems-talk] KOH etch fo silicon with very low surface
roughness


Thanks for your answer!!

In which position do you place the sample in the bath to minimize the effect
of the bubbles? At the moment I am placing it vertical and I am also using a
stirrer in the bath. Basically, the patterns are directly in the flow of the
KHO solution.....

Best regards,

Sonia.