I believe the 13.56 MHz is use to produce high density plasma and the 2 MHz
is used bias the wafer.

-----Original Message-----
From: William Lanford-Crick [mailto:[email protected]]
Sent: September 8, 2005 4:16 PM
To: 'General MEMS discussion'
Subject: [mems-talk] ICP-RIE coil frequency

         Hi Group,

         We have 2 ICP-RIE system.  1 is a PlasmaTherm (now Unaxis), with
the ICP coil at 2 MHz.  The other is an STS Bosch process system with the
coil at 13.56 MHz.  Both system have platen power at 13.56 MHz.

         Can somebody tell me what difference the ICP coil frequency makes?
Why would we want 2 MHz vs. 13.56 Mhz?  Is there an advantage to having the
coil and RIE power at 2 different frequencies?
         Thanks for any info you an supply,

         Bill