Rev. Draft 06

SHORT OPERATING PROCEDURE FOR TESCAN

GAIA AND XEIA FIB/SEM INSTRUMENTS

Purpose

Short Operating Procedure (SOP) provides generic guidance for safe operation of TESCAN instruments in SEM and FIB modes by trained operators.

Conventions

Bold Text – Icons, GUI areas, wizards, Names/Passwords, and pop-up windows

Bold>With>Arrows – directions to items in the toolbar of Tescan application

“Bold with Quotes Text” – GUI buttons

“Regular with quotes text” – status messages and indicators

CAPITALIZED TEXT – following conventions in Tescan software

BOLD CAPITALIZED TEXT – warnings for avoiding severe damage to instrument

General Comments

Standard operation procedures intended to serve as guideline for basic operation and do not cover neither advanced alignment techniques nor user-specific applications. Advanced training is available from AIM Lab personal and additional information in form of files is available on tool pages of AIM Lab website.

Normally GAIA/XEIA systems will be left in Log Off condition (application screen is closed) with main chamber pumped down. If application was left open by the previous user, then you should choose File > Log Off and then Log On with your own user name. Do not switch system to STANDBY mode.

SEM Operation

NO ANY MAGNETIC MATERIALS (STEEL, IRON, NICKEL, COBALT, ETC...) COULD BE LOADED INTO GAIA, XEIA, or SU-70 INSTRUMENTS WITHOUT PRIOR APPROVAL AND DIRECT SUPERVISION BY AIM LAB PERSONNEL

MULTIPLE SAMPLES LOADED ONTO CAROUSEL MUST HAVE THE SAME HEIGHT. LOADING SAMPLES WITH DIFFERENT HEIGHT MAY CAUSE COLLISION WITH DETECTORS AND DAMAGE THE INSTRUMENT

I. Starting session

1.  You must have a reservation prior to starting your session.

2.  Check logbook; make sure that there are no problems reported by previous user.

3.  Write down your name and exact time to the nearest minutes for starting and ending your session in the logbook and check sub-systems used in your project.

II. Mounting sample

Securely mount sample on standard SEM stub, ensuring continuous grounding path for removal of electrostatic charge from the specimen. Ask for assistance if you are unsure on mounting the sample or if you experiencing charging problems.

III. Logging into the system.

Choose your user name from the drop-down menu and enter your password to log in. After initialization verify that “System Status” indicator is green and there are no error messages reported. Contact AIM Lab staff if you see any error messages.

IV. Inserting specimen

  1. Check status of Column Pressure and Chamber Pressure indicators in “Vacuum Control” window. If any of indicators are red then click PUMP to start pumping.
  2. Check status message in “Vacuum Control” window. If status reads “Vacuum ready” then proceed to vent the chamber.
  3. If status reads “Pumping, Standby mode” or “Vacuum ready, Standby Mode” then press “STANDBY” button and click “Yes” to re-initialize the microscope.
  4. After system pumps down and Column/Chamber pressure indicators become green click VENT, click “Yes” to confirm.
  5. On XEIA system – click “Pump” button in Ion Beam window
  6. Press either “Home” in Stage Control window to lower stage to the safe height for sample loading.
  7. Once pressure in the chamber reaches atmosphere, the door opens slightly and could be opened with minimal force.

8.  Put on gloves, use tweezers, and under any circumstances do not touch specimen or anything inside the chamber with bare hands.

  1. Insert SEM stab with specimen into holder on the stage, and secure it with the setscrew. Finger-tight screw with the Allen wrench.
  2. If Chamber View cameras are not open then click on “Camera” icon in the Main Toolbar window to observe insertion of specimen into the chamber.
  3. Close chamber door slowly and carefully, while observing specimen height on the Chamber View to make sure that the specimen will not touch anything within the chamber as the door is closed. Do not slam the door - you may cause damage to liquid-metal ion source and electron source.
  4. Push the door firmly and click “PUMP” in “Vacuum” window.
  5. Wait for Column Pressure and Chamber Pressure indicators to become green and for message “Vacuum ready” to appear in the Vacuum window.
  6. If deposition or gas-assisted etching is planned during the session, then start heating or cooling necessary precursors in Gas Injection System window.
  7. On XEIA system click “Pump” button in Ion Beam window to start pumping plasma ion source.

V. Obtaining image

1.  Click on “BEAM ON” button in Electron Beam window.

2. Verify that “Continual” button in Info Panel is active.

3. Click on Beam Intensity in Info Panel and set it to 3 or 4.

4. Turn scroll-wheel of the mouse to set SEM scanning Speed 3 or 4.

5. Click on “MODE” icon next to SEM Scanning window and choose “FIELD.”

6. Right-click on MAG icon next to SEM Scanning window, or on live SEM image and choose “Minimum Magnification” – image should appear.

7. Click on “Auto” icon next to SEM Scanning window to optimize brightness and contrast.

If no image is visible upon completion of “Obtaining image” procedure check that SE detector is chosen in SEM Detectors & Mixer window.

VI. Lateral stage movement and sample positioning

1.  If “Stage Control” window is did not open automatically then open it by clicking on stage icon in Main Toolbar.

2.  If Standard Tescan Carousel is not visible in Stage Control window the click on arrow icon at the bottom-right corner of the Stage Control window to open the carousel view.

3.  Movement between positions on standard carousel may be accomplished by clicking on the desired carousel position at the bottom of Stage control window.

4.  Continuous lateral movement of the stage may be accomplished by pressing on left/right/up/down arrow buttons in the Stage Control window.

5.  Bringing a feature to the center of field of view may be accomplished by doing middle-click (by the scroll-wheel) on the feature of interest.

6.  Correcting rotation of the sample may be accomplished by clicking on “Define UV” button in the stage control window and using “Align Sample” function.

7.  Click on the location of carousel with your sample. Sample would be brought into view field.

8.  Find object suitable for focusing and adjusting SEM image and center it within View Field.

Note that X/Y stage may not have sufficient resolution for sample positioning at high magnifications. Adjusting image position at magnifications 100K or higher is better done with electron beam Shift function available through “Info Panel” window.

VII. Establishing WD&Z link my matching SEM WD to Stage Height

FAILURE TO FOLLOW WD&Z LINK PROCEDURE EXACTLY AS WRITTEN COULD LEAD TO COLLISION OF SPECIMEN WITH POLEPIECE OF SEM AND CAUSE SEVERE DAMAGE TO THE INSTRUMENT

1.  Click on MAG icon next to SEM Scanning window and increase magnification to obtain ~200um View Field by rolling trackball in horizontal direction.

2.  Click on WD icon next to SEM Scanning window and focus image by rolling trackball in horizontal direction. Do not expect image to be perfect at this stage.

3.  Find good feature for image adjustments and center it in the View Field.

4.  When image is focused within ~200um View field click on the right-pointing arrow next to WD&Z input field in Stage Control window and choose 25mm working distance. Observe stage motion and keep mouse pointer hovering over the ”STOP STAGE” button to quickly stop the stage if collision is imminent.

5.  Re-center your sample in the middle of View Field.

6.  Change SEM imaging mode to RESOLUTION

7.  Press Auto Brightness/Contract button next to SEM Scanning Window to correct contrast and brightness of the image.

8.  Correct focus by adjusting WD

9.  Change working distance to 10mm by clicking on the right-pointing arrow next to WD&Z entry field in Stage Control window.

10.  If needed, increase magnification to obtain View Field of ~100um or less and repeat WD adjustment. If after the adjustment WD&Z reading changes then click on the right-pointing arrow next to WD&Z field and change it back to 10mm.

11.  Repeat WD adjustment at WD&Z 10mm until (a) image is in focus in RESOLUTION mode and (b) distance in WD&Z field in Stage Control window is between 9.950mm and 10.050mm

12.  For FIB operation reduce WD&Z to 5mm.

13.  For high-resolution SEM operation further reduce WD&Z in 1mm steps. Do not attempt operating SEM with WD&Z <2.5mm.

14.  Correct brightness/contrast, WD and stigmation if needed.

After completing this procedure sample should be at the desired working distance (typically 10mm or less), with focused image in RESOLUTION mode and WD&Z reading matching the working distance to within +/-50um.

V. Centering electron beam and adjusting image quality

1.  Find good object within your sample with sharp edges to use for adjustment.

2.  Switch to RESOLUTION mode.

3.  Click on “Manual Column Centering” icon next to SEM Scanning window. The “Manual Centering Wizard” should appear.

4.  Click on “Next” button in “Manual Centering Wizard” – image should start wobbling within the partial scan window.

5.  Double-click on SEM image outside of the partial scan window to enable full-image scan.

6.  Use trackball to stop motion of the image. Use scroll wheel of the mouse to adjust speed of scanning if needed.

7.  Once motion of the image is stopped click on “Finish” button in Manual Centering Wizard to end beam centering.

8.  Click on WD icon next to SEM Scanning window to adjust focus and click on STG icon to correct astigmatism.

9.  Repeat beam centering, WD, and STG adjustment until image quality is adequate.

10.  Use scroll wheel of the mouse to change scan speed if necessary.

11.  Use “Auto” icon to correct brightness and contrast levels if needed.

12.  Repeat beam centering adjustment in FIELD mode and correct X/Y offset between FIELD and RESOLUTION modes.

VI. Acquiring photo-quality image

1.  Click on “Image Acquire” icon next to SEM Scanning Window to acquire the image.

2.  Enter notes/comments and click OK. If you do not wish to enter comments for every image then appearance of comments screen may be disabled in Options menu

3.  Click “Save” to save the image. Default image folder is located: C:\Tescan\Gaia(Xeia)\users\<yourusername>\images

4.  To change pixel count and acquisition parameters of the image go to SEM menu and choose “Image Parameters.”

5.  Good default set of parameters for high-quality image acquisition is image size1024 OR 2048 pixels and:

(a)  Scan Speed 3, average 50 to 100 images, or

(b)  Scan Speed 2, average 100 to 250 images, or

(c)  Scan Speed 7, no averaging.

6.  Image from FIB or SEM Scanning window can be saved by selecting corresponding Scanning window and going File > Save menu.

VII. Changing acceleration voltage

1.  If acceleration voltage needs to be changed then click on HV in Info Panel and change acceleration voltage in the Pad either by entering the desired value.

2.  Reduce magnification and adjust brightness/contrast to obtain usable image.

3.  Perform Beam Centering, WD, and STG adjustments to optimize image.

VIII. Using retractable Detectors

TBD

X(a). Ending session for GAIA system

1.  Switch off acceleration voltage by clicking blue-colored BEAM ON button in the Electron Beam Menu window. SEM isolation valve will shut off and color of BEAM ON button will change from blue to grey.

2.  If FIB was used during the session, then switch off the ion source and FIB high voltage by clicking “High voltage” button in Ion Beam window.

3.  Click “Home” in the Stage Control window to return stage to safe working distance and zero tilt.

4.  If you created any stage memory locations then clear them all.

5.  If you created any stage tags then clear them all.

6.  Click on “VENT” button in in vacuum control window and wait for chamber to reach atmosphere pressure.

7.  Remove your specimen, gently close door, and pump the chamber.

8.  Log off the system by choosing menu File>Log Off

9.  When prompted to switch to STANDBY mode click “NO”

X(b). Ending session for XEIA system

1.  Switch OFF acceleration voltage by clicking blue-colored BEAM ON button in the Electron Beam Menu window. SEM isolation valve will shut off and color of BEAM ON button will change from blue to grey.

2.  If FIB was used during the session, then switch off ion source and FIB high voltage by clicking “High Voltage” button in Ion Beam window.

3.  Stop pumping plasma ion source by clicking blue-colored “Pump” button in Ion Beam window. Status message “Waiting for good vacuum” will appear at the top of Ion Beam window.

4.  If you created any stage memory locations then clear them all.

5.  If you created any stage tags then clear them all.

6.  Click on “VENT” button in in vacuum control window and wait for chamber to reach atmosphere pressure.

7.  Click “Home” in the Stage Control window to return stage to safe working distance and zero tilt.

8.  Remove your specimen, gently close door, and pump the chamber.

9.  Once vacuum indicators reach green status, re-start pumping the ion source by clicking “Pump” button in the Ion Beam window.

10.  Log off the system by choosing menu “File”>”Log Off”

11.  When prompted to turn to STANDBY mode click “NO.” Do not put system into STANDBY mode.

Collecting spectrum by EDAX EDS

As a general guideline for SEM operation with EDS, acceleration voltage of 5KV is reasonable choice for detecting light elements and 15KV may be preferred for heavy element detection. Working distance in the range of 5mm to 10mm and FIELD imaging mode are recommended to maximize counts. As a general guideline for EDS setup, Amp Time between 1.92 to 7.68 is recommended for detecting light elements.

1.  If EDAX computer is OFF then power it up. Windows password is apollo

2.  If TEAM software is not open then start it by double-clicking on the icon at the top-center of the desktop.

3.  Login to TEAM application with default user name EDAX_EDS and password eds

4.  Click on thermometer icon at the bottom-right corner of TEAM software. Cool the detector and wait for Detector Ready indicator to become green.

5.  On XEIA system open detector shutter(s) in Tescan application by going to menu “SEM” > ”Detector Shutter”