From mcvittie at snf.stanford.edu Thu Apr 22 09:55:53 2004 From: mcvittie at snf.stanford.edu (Jim McVittie) Date: Thu, 22 Apr 2004 09:55:53 -0700 Subject: Comment pquest 2004-04-21 21:45:37: external fiber optic Message-ID: <4087F918.62010F9C@snf.stanford.edu> PQuester Users, Up until now on the PQuest, you have been restricted to using wafers which had fairly reflective backsides. The reason for this restriction was that the wafer sensor in the load lock was operating in the reflection mode. The particular wafer sensor on the tool has both a red LED source and a photo transistor. In the reflection mode, a single optical fiber is split and connected to both the LED and the phototransistor. The output of this fiber was placed under the wafer in the loadlock. It only sensed a wafer if enough reflected light off the wafer backside made it back to the fiber and onto the phototransistor. In looking into this sensor, I found that it can also be operated in a transmission mode if a second fiber is added. After a lot of web searching, I located a fiber made for this application. Last night, Cesar temporarily installed the second fiber and switched the sensor to transmission mode. It appears to work great in that it senses all wafers. We can go back to the reflection mode in a few minutes if needed. After a few weeks if there are no problems, we will make the transmission mode fiber installation permanent. Thanks, Jim -------------- next part -------------- A non-text attachment was scrubbed... Name: mcvittie.vcf Type: text/x-vcard Size: 422 bytes Desc: Card for Jim McVittie URL: From mcvittie at snf.stanford.edu Tue Apr 27 09:44:34 2004 From: mcvittie at snf.stanford.edu (Jim McVittie) Date: Tue, 27 Apr 2004 09:44:34 -0700 Subject: PQuest is free Message-ID: <408E8DF2.B1E938C7@snf.stanford.edu> I was going to a training session this morning for 2 new users but they have a conflict and can not make it. The tool is free to use. Jim -------------- next part -------------- A non-text attachment was scrubbed... Name: mcvittie.vcf Type: text/x-vcard Size: 422 bytes Desc: Card for Jim McVittie URL: