Scanning Electron Microscope in Our Facility

Transcription

1 SEM Training

2 Scanning Electron Microscope in Our Facility Specifications Table SEM ESEM FE-SEM-F FE-SEM-J FE-SEM-H FE-SEM-CZ Device name TM3030 Inspect S50 Inspect F50 JSM-7600 S-4700 Marlin compact Company HITACHI FEI FEI JEOL HITACHI Carl Zeiss Emission type Tungsten Tungsten Field emission Field emission Field emission (cold) Field emission Acceleration voltage 5kV, 15 kv 200V to 30kV 200V to 30kV 100V to 30 kv 20kV 100V to 30kV Vacuum level Low Low / High High High High High Magnification 15x to 60000x 25x to x 30x ~ Observation mode BSD / SE / Mix SE/ BSE/ STEM SE SE SE/BSD EDX Bruker Bruker EDAX - - Bruker Characteristics Table SEM ESEM FE-SEM-F FE-SEM-J FE-SEM-H FE-SEM-CZ setting difficulty with Magnetic property Limitation of thickness Recommended specimen diameter Easy Easy Easy Troublesome* (with the rod) Troublesome* (with the rod) Not allowed Allowed** Allowed** Not allowed Not allowed Allowed** 50mm non non 30mm non non The diameter of specimen must not exceed the diameter of stub you chose. Easy* *Special attention is particularly necessary when you use the rod in order to insert the specimen into the SEM. ** Except powdery specimen. You have to make sure that specimen with magnetic property must be stacked tightly on the stub.

3 FE-SEM-J Observation Flow Saving Data And Analysis preparation Error check Closing Procedure Start Observation ESEM FE-SEM-F FE-SEM-H FE-SEM-J Confirm the SEM Chamber by CCD Confirm Error Message of SEM And PC Monitor Mount on The Stub Mount Stub on The Holder of SEM Measure The Height of The Holder Measure The Height of The holder Set The Stage of SEM to The Exchange Position Insert The Holder into The SEM Chamber Switch On Electron Beam Select WD=12mm at 250x of The High Mag Mode Select Home Stage or Appropriate WD Adjust The Focus at The Present Condition Link (Z) to WD Gently Adjust The Actual Height of (z) Manually, for Focusing The Image With The WD You Choose Start Observation With The Low Magnification Save Images Low Vacuum / EDX BSD,STEM / EDX Switch Off Electron Beam Confirm The SEM Chamber by CCD Set The SEM Stage to The Exchange Position Take Out And Data Leave The Room After Verifying That The Error Message Does Not Appear

4 Prohibited Matter We understand really well that you are full of vitality. However,,,, 10 mm Power is not necessary for the precision instrument Do not use your POWER, FORCE and STRENGTH to SEMs because SEMs are the FRAGILE, SENSITIVE and DELICATE instruments Proceed every single step GENTLY, CAREFULLY and CAUTIOUSLY

5 Prohibited Matter We also understand that you wish to set your specimen as it is. However,,,, WD =10mm The height that SEMs do not expect WD=10mm SEMs are able to understand only the distance between the column and the area in focus on the specimen surface; the height of the container rim never be considered by SEM. Thus, when you change the observation area while moving the stage (Z), the rim might cause serious damage to the SEMs. Likewise, we do not recommend to set up several specimens with large differences in height on the same stab. Do not set up any kind of Container into SEMs Do not set up several specimens with large differences in height on the same stab.

6 Z(Height), FWD(Free Working Distance) and WD What is Z? What is FWD and WD? Distance from the stage bottom Distance from the column to the specimen surface Distance from the column to the stub cylinder * Every SEM has slightly different idea about Z. The distance from the column to the area to be in focus on the specimen surface *FWD and WD are same; WD is called differently depending on the company. You must link Z and WD immediately after switched on the beam and adjusted the focus. Otherwise, SEMs are not able to understand the actual height of the specimen. As a result, specimen hits the column and will give it a serious damage to SEMs. colu mn sample colum n Holder SEM stage

7 Do you know why it is so important to link Z and WD? Because Are you aware??? 1. Preventing SEMs From Being Damaged (*see previous slide) 2. In Order To Obtain High Resolution Images 3. In Order To Obtain Precise EDX Result Sufficient volume of secondary electrons or backscattered electrons from the specimen surface that reach to each detectors are necessary for obtaining High Resolution Images. Likewise, sufficient volume of characteristic X-rays are necessary for the precise EDX Result. Therefore, individual detectors are set up at the most appropriate angle and position to absorb secondary electrons, backscattered electrons and characteristic X-ray at the recommended WD. Thus, it is extremely important to set the SEM stage correctly, make SEMs understand the position of (Z) and link (Z)and WD. Stage(Z) is too close to column and detector Saturation Z = Recommended WD Stage (Z) is too far to the detector Low signal

8 29 mm 12 mm 38mm 30mm 29 mm How to link Z and FWD(ESEM and FE-SEM-F) or WD(FE-SEM-H, FE-SEM-J) Step1: Measure the height of specimen and specimen holder ESEM and FE-SEM-F FE-SEM-H FE-SEM-J 10 Scale Ramp Stage Base Scale Maximum height of the specimen 10 mm Top surface of the cylinder of the specimen holder Scale Scale Scale Total Height of and Holder MUST BE 10 of the scale 29 mm - Limitation of Height Indication of Z of the user interface before linking Z and FWD(WD) mm from the cylinder top surface The red arrow goes on from the bottom non non

9 Recommended WD = 10 mm Recommended WD = 12 mm Recommended WD = 8 mm How to link Z and FWD(ESEM and FE-SEM-F) or WD(FE-SEM-H, FE-SEM-J) Step2: Adjust the focus and confirm value of WD at this moment from the bottom of the image ESEM and FE-SEM-F FE-SEM-H FE-SEM-J Recommended WD 10 mm 12 mm 8 mm (Home position) (2-1) SEM Images Right After Switch on The Beam Different value The images are out of focus (2-2) Models of SEM Stage Position, Electron Beam and Recommended WD of (2-1) Electron Beam Electron Beam Electron Beam

10 Actual WD = 12 mm Actual WD =13.9 mm Actual WD = 6.3mm How to link Z and FWD(ESEM and FE-SEM-F) or WD(FE-SEM-H, FE-SEM-J) Step2: Adjust the focus and confirm value of WD at this moment from the bottom of the image ESEM and FE-SEM-F FE-SEM-H FE-SEM-J Recommended WD 10 mm 12 mm 8 mm (Home position) (2-3) Images After Adjusting Focus The images are in focus (2-4) Models of SEM Stage Position, Electron Beam and Actual WD of (2-3) Step3: Link Z and current WD by Clicking. Confirm the indication of Z and WD bottom of the image are now more or less similar value. * The arrow changes to the transparent and downward direction.

11 Actual WD = 12.0 mm Gap = 2.0 mm Gap = 1.9 mm Recommended WD = 10 mm Actual WD = 13.9 mm Recommended WD = 12 mm Actual WD = 6.3 mm Recommended WD = 8 mm Gap = 1.7 mm How to link Z and FWD(ESEM and FE-SEM-F) or WD(FE-SEM-H, FE-SEM-J) Step4: Read the gap between the actual WD, which is presented bottom of the scanned image, and the recommended WD. ESEM and FE-SEM-F FE-SEM-H FE-SEM-J Gap (mm) = = 2.0 Gap (mm) = = 1.9 Gap (mm) = = -1.7 Step:5 Adjust the height in order to be in focus image in the recommended WD. And confirm WD bottom of the image and Z of the user interface shows more ore less similar value. (5-1) Models of SEM Stage Position, Electron Beam and WD After Moving Stage Position (Z) Make higher the stage position by 2.0 mm Make higher the stage position by 1.9 mm Make lower the stage position by 1.7mm (5-2) Just Focused Images After Moving Stage (5-1) Make sure the image is in focus and, the actual WD and recommended WD are more ore less similar value Arrow is indicated downward

12 How to link Z and FWD(ESEM and FE-SEM-F) or WD(FE-SEM-H, FE-SEM-J) ESEM and FE-SEM-F FE-SEM-H FE-SEM-J Do not forget to click, or to link WD and Z every time when you mechanically move Z. Appeared when SEM does not understand the stage height Appeared after stage drastically moved Appeared after WD and Z are linked Appeared when SEM does not understand the stage height Step 6: Select different observation condition from recipe, if you wish. Then, repeat step 1-6 again. Step 7: Whenever you drastically change the observation area, or simply change the specimen, you must repeat those steps above.