Appendix 9: Start-Up Procedures for the Vega TS 5136 XM Scanning Electron Microscope

Appendix 9: Start-up procedures for the Vega TS 5136 XM Scanning Electron Microscope. (This packet was compiled during the 2003-2004 Academic Year.) ______

Computerized SEM Procedures Vega TS 5136 XM (Dr. Stan Trauth and Chris Brown) Revised 8-4-04

Table of Contents

Initial start-up...... pg 2 Shutting down the microscope...... pg 3 Low magnification (15x)...... pg 3 Fine focusing for up to 6kx mag...... pg 4 Fine focusing for 6kx + mag...... pg 4 Parameter Ranges...... pg 6 Gun alignment...... pg 7 Changing specimens...... pg 7 Contacts...... pg 8 Troubleshooting...... pg 9

-1- Initial Start-Up

1. Turn on nitrogen gas at the main valve on the tank. Regulator pressure has already been preset (~70 PSI).

2. Double click on the Vega TC icon on the windows desktop. (This will start the Vega TC program.)

3. On command, enter User’s password. If you have no password, you must sign on as a guest, and will therefore be limited in the options available to the program. Also, the program will remember the user’s last program configuration.(Mag, WD, etc.)

4. Load specimens by following procedures in the Changing Specimens section.

5. Click on the PUMP button at the bottom right of the screen. This will start the pressurization in the chamber. When the Column and Chamber pressure bars have turned green, you may proceed with the rest of the start-up. (Note: the chamber pressure should level out at 8.43e-3 Pa, and the column pressure should level out at 8.2e-3 Pa. The pressures may be a little above or below these specified pressures.)

6. The High Voltage (HV) button should then be pressed to start power through the specimen. An HV of 10.0 is the most reasonable starting voltage, but may be adjusted as needed.

7. Make sure that you are working in Resolution Mode with the SE detector. These options are available on the right side of the screen.

8. Start with a Z value of less than 15mm. The Z value can be changed within the stage control window by entering a value and pressing enter on the keyboard. The parameter sheet should be consulted for the magnification that you want to achieve.

9. Select automatic filament heating, which can be found in the lower right info panel along with HV and Pump buttons. This will automatically align the gun and adjust the filament heating.

10. To start scanning the specimen, open a scanning window (if there is not one already open on start-up) by pressing the top button on the right side of the screen.

11. Within the scanning window, right click with the mouse and select AUTO WD from the

-2- menu. This value should approximate your Z value.

12. Right click again and select AUTO Signal, which will automatically set the brightness and contrast. If the AUTO Signal is not to your perfection, it can be manually changed by depressing the signal G/BL on the right side of the screen. The trackball can then be used to manually change the brightness and contrast one at a time by moving the trackball in a horizontal motion, and then in a vertical motion.

13. Right click again and select AUTO Stig. This will automatically adjust the stigmators.

14. For the best image, parameters should then be finely manipulated by clicking on the words in the panel near the right side of the screen. These parameters include WD, Signal G/BL, and Stig.

Shutting Down the Microscope

1. Turn off high voltage by pressing the HV button in the lower right panel.

2. Once the high voltage is completely off, press the VENT button, which is just below the HV button. This will vent the chamber to approximately 4.0e4. The chamber door should then be able to open, but may require some force.

3. Remove specimens according to the Changing Specimens section.

4. Select the OFF button in the lower right panel.

5. Turn off the nitrogen gas at the main valve on the tank.

Low Magnification (15x)

1. Right click the MODE icon on the far right side of the screen. Select Field mode.

2. Lower stage to approximately 25 mm. This can be done by changing Z to 25 within the stage control panel.

3. Manually enter 25 mm as the working distance by selecting the WD in the panel on the right

-3- side of the screen. Tweak this distance with the trackball to obtain a focused image.

4. Adjust the high voltage to no higher than 10 kV. The high voltage must be turned off to adjust this parameter. 5. These settings should allow for a ½" field of view(FOV). The field of view may be increased by lowering the Z value to 30mm and following in 5mm increments until desired FOV is obtained. Make sure that the WD approximates your new Z value.

Fine Focusing Procedures For Up to 6kx Magnification

1. Select a high magnification either by manually entering a number or by using the trackball to climb to a high magnification. These procedures are geared toward magnification between 4kx and 6kx.

2. Perform an AUTO WD by right clicking within the scanning window and choosing AUTO WD from the menu.

3. Perform an AUTO Signal by the same procedure in #2.

4. Manually tweak the WD and Signal G/BL by depressing their corresponding buttons on the right side of the screen. The best image should be obtained by this tweaking.

5. Perform an AUTO Stig, which will automatically set the stigmators, by right clicking within the scanning window and choosing AUTO Stig.

6. Manually tweak the stigmators by depressing its corresponding button on the right side of the screen. This should obtain a better focused image.

7. Once you are ready to capture an image, slow the scan speed down to between 7 and 9. This can be done by using the wheel on the mouse. The slower that you scan, the better the image you will get.

8. To save an image, go to the menu at the top of the screen and select File. Then, click on Save. To ensure the best image, save the file as the scanner just reaches the bottom of the scanning window.

Fine Focusing Procedures For 6kx + Magnification 1. Select a high magnification either by manually entering a number or by using the trackball to

-4- climb to a high magnification. These procedures are geared toward magnification between 6kx and 20kx.

2. The stage should be moved to a Z value of less than 10mm. The higher the magnification desired, the higher the stage needs to be raised. Keep a watch on the video in the lower left side of the screen to ensure that you do not hit the bottom of the gun.

3. Perform an AUTO WD by right clicking within the scanning window and choosing AUTO WD from the menu.

4. Manually tweak the WD by depressing its corresponding button on the right side of the screen. The AUTO WD performed in the previous step may be tweaked some at these higher magnifications to produce a more focused image.

5. The gun alignment should now be checked by selecting GUNCENTRING in the panel on the right side of the screen, within the drop down menu. For manual alignment, manipulate the parameters with the trackball to obtain the brightest image possible. For automatic alignment, select AUTO just below the drop down menu.

6. The probe current should now be increased to approximately 12-13 for magnifications around 10kx or 16-17 for magnifications around 15kx+.

7. Perform an AUTO SIGNAL by following the path in step 2.

8. The objective lens should now be centered. Create a raster window within the scanning window by a double-left click of the mouse while inside the scanning window. Decrease the magnification to approximately 1kx. Turn on the wobbler by depressing the WOB button within the right panel. Now turn on the objective lens by depressing the OBJ button within the right panel. The wobbler should be taking the specimen in and out of focus. To center the objective lens, manipulate the parameters for the objective lens with the trackball. As you increase and/or decrease parameters, the wobble effect will decrease, in that the amount of wobbling will decrease to the point where the image is hardly moving in and out of focus.

9. Raise magnification back to previous point (magnification at which you want to look at your specimen). Remove the raster window with a double-left click of the mouse somewhere within the scanning window but not within the raster window.

10. Refocus the specimen by performing steps 2 and 3 again.

11. To automatically set the stigmators, perform an AUTO STIG by right clicking within the scanning window and choosing AUTO STIG.

12. Manually tweak the Stigmators by depressing its corresponding button on the right side of

-5- the screen. This should obtain a better focused image.

13. Refocus the specimen by performing steps 2 and 3 again.

14. Continue to adjust stigmators and working distance by the previous steps until a fine focus is achieved.

15. Once you are ready to capture an image, slow the scan speed down to between 8 and 10. This can be done by using the wheel on the mouse. The slower that you scan, the better the image you will get.

16. To save an image, go to the menu at the top of the screen and select File. Then, click on Save. To ensure the best image, save the file as the scanner just reaches the bottom of the scanning window.

Parameter Ranges

Note: The following table establishes parameter range values for certain magnifications. These values are only a guideline. You may need to adjust these values, and some even out of the parameter range for certain specimens.

Kv1 WD2 PC3 100x mag 10-20 15-20 10 100-1000x mag 10-20 15-20 10-12 1kx-10kx mag 15-20 10-15 12-16 high mag 20 3-10 16-19 1high voltage 2working distance 3probe current

-6- Gun Alignment Procedures

Note: The gun should be aligned if transitional motion is detected in the image or if the image will not become clear.

1. Select GUN from the top right info panel. Create a raster window in the scanning window by double left click. Within this raster window (which is the only area of the scanning window that is being scanned) manually manipulated the trackball in horizontal and vertical motions to obtain the brightest image possible. Sometimes this image will be almost completely white, but AUTO Signal will correct this.

8. The objective lens should now be centered. Create a raster window within the scanning window by a double-left click of the mouse while inside the scanning window. Decrease the magnification to approximately 1kx. Turn on the wobbler by depressing the WOB button within the right panel. Now turn on the objective lens by depressing the OBJ button within the right panel. The wobbler should be taking the specimen in and out of focus. To center the objective lens, manipulate the parameters for the objective lens with the trackball. As you increase and/or decrease parameters, the wobble effect will decrease, in that the amount of wobbling will decrease to the point where the image is hardly moving in and out of focus.

Changing Specimens

Note: The stage will hold 7 specimens at one time. However, larger samples may need to be changed out.

*IF YOU ARE JUST STARTING THE MICROSCOPE, MOVE TO PROCEDURE # 3.*

1. Turn off the HV, by depressing the HV button.

2. Select the VENT button in the lower right info panel. This will stabilize the pressure inside the chamber allowing you to open the door.

3. Lower the stage by entering a value of 90.00 for Z within the stage control panel.

-7- 4. Once the pressures for both the column and chamber have dropped to their lowest value (there will still be some pressure registered on the column and chamber bars), open the door to the chamber. At a column pressure of 4.0e4, the door should open but may require some force.

5. The stage can then be spun around by clicking the opposite specimen number in the stage control info panel. This will spin your specimen to the front of the opening.

6. Using the small allen wrench from the SEM toolbox, gently turn the screw to the left. The specimen and stub should then come out freely, if not, loosen the screw a little more.

7. Using the tweezers from the same SEM toolbox, grab the stub and gently lift up to remove the specimen.

8. Place your next specimen in the proper numbered stage spot with the tweezers. The specimen should be mounted to a stub, which can be found in the SEM toolbox.

9. Using the allen wrench, gently tighten the screw to hold the specimen in place. Turn allen wrench just until tight. DO NOT put much force into tightening the screw.

10. Close the door to the chamber.

11. Pressurize the chamber and column again by depressing the PUMP button. Wait until the chamber and column bars turn from red to green before proceeding.

12. Raise stage to approximately 15 mm. Return to Step 4 of the Initial Start-Up.

Contacts

Note: The contacts listed in this section are to CamScan USA. This is the company that developed the SEM and its computer software. They are very helpful people and can assist you with just about any problem. Feel free to call them if the need arises. The names of the staff are listed on the following page.

Address: CamScan USA Inc. 508 Thomson Park Drive Cranberry Township, PA 16066-6425

Phone: (724)772-7433 Fax: (724)772-7434

-8- Note: Jack will be able to solve most problems, if not, he will be able to direct you to the person that you need to help you. So when you call, ask for Jack Mershon.

-John Van Noy, President and Service Manager: [email protected]

-Tony Owens, Vice President and Applications Manager: [email protected]

-William J. (Jack) Mershon, Applications Engineer: [email protected]

-Marjorie Counihan, Office Manager: [email protected]

Troubleshooting

1. CHAMBER WILL NOT VENT: Pump the system down by depressing the PUMP button in the panel at the lower right of the screen. Depress the UNIVAC button in the same panel. You should hear the valve blow. Depress the VENT button in the same panel. The chamber should now fully vent.

2. WILL NOT OBTAIN A GOOD FOCUS: First, ensure that you have a proper Z value for the magnification that you want to achieve. Perform an AUTO WD and an AUTO STIG and slow the scan speed down. If you still do not have a good focus, check the Gun Alignment section. If still no luck, increase your probe current and manually set all of the parameters. If all else fails, throw the scope out of a window and then try again.