[labnetwork] STS multiplex ASE high coil reflectance issues

Fri Jul 12 14:50:11 EDT 2013

Hi,
  We ran into a similar issue with poor tuning on our platen bias and it turned out to be simply a loose RS-232 going to the tuner.  Incidentally, we have an older STS (early 2000 model) here at U of Louisville and as the system has aged we continue to run into progressively worse communication issues between the various components and controller that does not seem to be related to loose cables.

Good luck!

From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Paolini, Steven
Sent: Friday, July 12, 2013 10:40 AM
To: Errol V. Porter; labnetwork at mtl.mit.edu
Subject: Re: [labnetwork] STS multiplex ASE high coil reflectance issues

Errol,  can you tune it manually? If so, something is interfering with the movement of the air caps. If you think both air (or vacuum) caps are freely turning and you can't tune it manually, remove the UHF cable from the generator to the match and using an ohmmeter, measure resistance from ground to the electrode, it should be 2 megohm or higher. If the resistance is lower, start removing parts such as shields and keep measuring till you find the short. Another avenue is to make sure the chuck RF is tuning, a mismatch of 20% or greater will create havoc for the coil tuning.  Best of luck,
  Steve Paolini
  Equipment Dood
Harvard University Center for Nanoscale Systems
spaolini at cns.fas.harvard.edu<mailto:spaolini at cns.fas.harvard.edu>

From: labnetwork-bounces at mtl.mit.edu<mailto:labnetwork-bounces at mtl.mit.edu> [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Errol V. Porter
Sent: Thursday, July 11, 2013 5:17 PM
To: labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>
Subject: [labnetwork] STS multiplex ASE high coil reflectance issues

Greetings,

We are trying to troubleshoot a problem with our STS ASE system generating nearly a 30% reflectance on the coil power. We have tested the supply using a dummy load with no problems. We have cleaned the inner ceramic shield and he reflectance remains. Any assistance you may have would be greatly appreciated.

Regards,

Errol Porter
University of Arkansas / HiDEC
700 W. Research Center Blvd
Fayetteville, AR 72701
Tel. (479) 575-2519
Mobile: (479) 236-0693
Fax (479) 575-2719
email: evporte at uark.edu<mailto:evporte at uark.edu>
http://www.hidec.uark.edu<http://www.hidec.uark.edu/>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mtl.mit.edu/pipermail/labnetwork/attachments/20130712/5f95789e/attachment.html>