G777 Lab 1: Introduction to SEMand Hitachi S3400N operationFor the next several weeks you will be learning about the proper operation of the Hitachi Variable Pressure S3400N Scanning Electron Microscope in Weeks 308. Each student will have various opportunities, from “cold start up’ to alignment and focusing and then imaging with the various detectors. Today we will set up and run in “normal” high vacuum mode.1. Safety (of machine) IssuesA. Sample height is #1 concern, if incorrect diameter/width and especially height is entered in software, the backscatter detector, CL detector and EBSD camera can be seriously damaged/ruined.There are 3 pieces involved in the sample holder, 2 are showntogether in picture to right. The 3rd is a flat aluminum piece with a“dovetail” grove in the bottom that slides onto the stage and has ahole to accept the rest; the top 2 pieces are screwed together (brassrod bottom, round aluminum plate top) and these slide snugly into thedovetail base.The user must use the white measuring tool to measure each andevery sample that is to be put in the machine. Place sample onwhichever mounting holder you use and then measure the totalheight of the sample plus the holder, relative to the bottom edge ofthe ruler, with the maximum height the sample reaches. For example,in the case here, there is piece of sticky tape with 100 micronfragments on it, so “standard” is the appropriate height (=0 mm). If Imounted it on a shorter brass rod, it might measure -5 mm.Do not forget to measure the width or diameter of the <largest of> either the sample or the holder forthe sample: for the case here, it is 26 mm. The software calls this “Size”.Note: this system works only if you insert the sample (on its holder setup described above) down all the way on the dovetail holder. If inserted sloppily and half way in, there could be serious damage done.There is ONLY software protection IF and ONLY IF the height isentered correctly in the software. The stage WILL crash into thebackscatter detector as it will only stop AFTER it makes electricalcontact. Damage will have been done.Question: You are looking at a defect at the end of the bolt, so youmount it as done in the image to the right. What is the correct valueto enter for the sample height? (a) 30 mm, (b) 20 mm, or anothervalue? ______(Note: there are two different sizes for the specimen base, the brasspiece. You would not use the shorter one for a thin sample, as therewould not be a valid height to enter in the software).Page 1 of 6AABB. You must ensure that there are no detectors inserted which could be collided with. Thus, both in starting up, and in finishing up, you must observe the followingprocedure:(1) Verify that the EBSD detector is retracted –A-- (0.2 mm on the smallbox) and the power on the KE box is OFF.(2) Verify that the CL mirror is retracted – blue knob is all the way (pickcorrect one): (a) counterclockwise ? (b)clockwise? And the high voltage(HT) is OFF -- B.2. Computer structureA. There are two different computer systems. The SEM uses the computer to the right of the user, with a outer door that hides it. The left monitor goes with the bottom right computer. The EDS computer on the other hand, sits to the far left on the floor. The EDS monitor is the right monitor. Remember: left monitor to right computer; right monitor to left computer.C. Once there, click the PC-SEM icon on the left desktop, and it will automatically take you to the PC SEM Manager environment. Master login is S-3400 – only need to do it if the computer has beenshut off. Otherwise it stays active. Login (usually not needed) is johnfD. Storage of images must be done with attention paid to first time, to locate the proper folders on the D drive, with individual users having folders under name of professor or workgroup -- D\All SEM User Files\ [groups here] \ [your own named folder]E. We’ll talk about the EDS computer later. 3. Start UpA. Can you see anything on the left monitor? If not, first turn it on to see computer state, i.e. to see ifcomputer is turned on/off or just sleeping.B. Cold Start Up – Not Normally Needed! (Key off: pumps and computer off). Turn Key to ON and then to START (like car ignition switch) for an instant, then EVAC to start pumps pumping, turn on left monitor, then follow C belowC. Warm Start Up – Not Normally Needed (Key ON: computers off, but pumps running): open Hitachi computer door, push button to turn on;D. Hot Start Up – Normal state (Key on, computers on, pumps running). Nothing needs to be done.E. At Windows prompt, enter geouser and password; The Hitachi PC-SEM operating system normally will be running. If not on desktop, check menubar to see if hiding. If not running, then click the PC-SEM icon on desktop, and login with account name. >> System can reach high vacuum (turbo pump) in 5 minutes from cold start.>>AIR button means “vent” chamber; EVAC button means “pump” chamber4. Steps to open machine to place new sample:A. If high voltage is on, turn it off. Wait three minutesfor filament to cool down before venting chamber.While waiting, follow steps B-D.B. Turn on the chamberscope IR light (right button onbox below little monitor).C. Be sure CL and EBSD detectors are retracted (seeother sections for details).D. Move the stage to the safe position, Z65 by clicking HOME Z65 at top right menu bar (this drops stage down away from detectors).Page 2 of 6E. Click right button (AIR) on front of machine to vent, or the AIR button next to Home Z65. Wait until you hear the second signal in about 2 minutes; grasp door by both sides and pull toward you.F. You should have already mounted and measured the size (diameter and height) of your sample, perthe instructions in the Safety section. Write them down if your memory is poor. Insert sample (see section on sample holder). Hold door closed while pressing the EVAC button (on front of machine iseasiest). Let go the door once the ‘sucking’ sound stops.G. A window will pop up and ask you to give the sample size. Click “Specimen” and 30 seconds later you will get another window where you enter the Diameter (“Size”) and Height in mm. Enter the correct values and click OK.H. For general EDS and back-scattered imaging, click the Analysis button on the STAGE menu to move the sample to a nominal “working distance” of 10 mm (10 mm below the bottom of the pole piece, or 6 mm below the bottom of the BSE detector). High
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