Zeiss ?IGMA VP-FE-SEM, User Manual

Page 1: ...EPA 600 R 14 211 October 2014 www epa gov research Zeiss ΣIGMA VP FE SEM User Guide R E S E A R C H A N D D E V E L O P M E N T ...

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Page 3: ...earch Laboratory Environmental Sciences Division Las Vegas NV 89119 Although this work was reviewed by EPA and approved for publication it may not necessarily reflect official Agency policy Mention of trade names and commercial products does not constitute endorsement or recommendation for use U S Environmental Protection Agency Office of Research and Development Washington DC 20460 ...

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Page 5: ...SEM Quick Start Revision No 2 May 2014 Page 1 of 16 Zeiss ΣIGMA VP FE SEM User Guide May 2014 By Jeremy Hilgar Darlene Usi ...

Page 6: ... Image 7 1 3 1 Detectors 7 1 3 2 Stage Control and Working Distance using Analog Controls 8 1 3 3 Stage Control Using SmartSEM s Stage Navigation 9 1 3 4 Scan Speed and Noise Reduction 10 1 3 5 Reduced Raster 10 1 3 6 Brightness and Contrast 11 1 3 7 Magnification and Focus 11 1 3 8 Stigmation and Focus Wobbles 11 1 3 9 Saving an Image 12 1 4 STEM Mode 13 1 4 1 Stage Navigation and the STEM Detect...

Page 7: ... not they are STEM compatible STEM compatible films and grids are always slotted to allow the passage transmission of electrons to a detector The most commonly used STEM compatible support film is the lacey carbon copper grid These grids can come equipped with a Formvar resin to enhance the stability of the lacey carbon network The usage of STEM compatible support films often proves convenient giv...

Page 8: ...t cannot be dissolved or suspended practically are attached to their support using either a conductive tape or a conductive paste as adhesives It is advisable to refer to the instructions specific to the adhesive being used before utilizing them Note that pastes and adhesives are not used when operating in STEM modes 1 1 3 Loading the Carousel Once prepared sample supports are fixed to an appropri...

Page 9: ...s Pressure and Vacuum Control This microscope uses pressurized gases for both vacuum chamber valve actuation and variable pressure viewing modes Prior to pulling a vacuum the operator must ensure that the instrument is being supplied with compressed air at a pressure of 87 psi 116 psi maximum If the operator intends to view samples under variable pressure mode which will not be discussed in this g...

Page 10: ...re at reasonable values EHT can safely be enabled by clicking the EHT status box at the bottom right of the SmartSEM window If successfully enabled the status box will change accordingly Note that it is common practice to change EHT values in small increments no more than 5 kV in hopes of prolonging the lifetime of the filament responsible for emitting electrons As a general rule lower EHT values ...

Page 11: ...ending on the currently selected adjustment mode 1 3 1 Detectors The instrument comes equipped with a variety of detectors that suit different situations For the purposes of this guide only the TV SE2 and STEM detectors will be covered The data coming from the detectors are viewed in the main viewing window at the center of the SmartSEM program screen At the bottom of this window can be found the ...

Page 12: ...ed media The stage is allowed to move through 5 degrees of freedom all of which are most easily controlled by the two control sticks found on the SEM Stage Control board Assuming the instrument was logged off correctly after its previous use the use of these control sticks will be disabled at startup To enable use of the control sticks click on the Stage tab under the SEM Control group on the righ...

Page 13: ...e that finding the specific sample of interest is too cumbersome using the analog controls on the SEM Stage Control board Here the Stage Navigation tool is a very useful aid The Stage Navigation tool can be launched from the docking side panel seen on the right of the main viewing window Click the arrow on the panel to expand it and then double click the item labelled Stage Navigation The window t...

Page 14: ...nel Noise is an inherent consequence of any sensing methodology The methods by which detector noise is handled by the software are ultimately averaging processes For the purposes of this guide only two noise reduction procedures will be utilized pixel averaging and line averaging Pixel averaging is effective when the operator is actively exploring the sample or when the sample image is changing of...

Page 15: ...ust box and select Auto BC On Different modes can be enabled per the operator s preference using this dropdown menu 1 3 7 Magnification and Focus The two primary factors that affect the characteristics of the final image are the magnification and focus of the microscope The current magnification level is shown at the bottom of the main viewing window in the textbox that reads Mag Y X Changing the ...

Page 16: ...cusing the image after correcting for any astigmatism and observing the results Often times the image will appear to move when the operator attempts to focus it This phenomenon is referred to focus wobble and occurs when the various electron beam apertures in the focusing column are in poor alignment To correct for focus wobble find a part of the image that has a high amount of contrast Focus upon...

Page 17: ...that of SEM mode This section briefly outlines the important differences between the two techniques It is assumed that the investigator has already loaded an appropriate stage evacuated the vacuum chamber and enabled EHT 1 4 1 Stage Navigation and the STEM Detector If the operator wishes to use the STEM detector a STEM compatible stage must be used Once the appropriate stage is loaded it is import...

Page 18: ...es The STEM detector is composed of both dark field and bright field components which are assigned labels called quadrants The bright field component of the detector is located directly in line with the electron beam and is responsible for detecting electrons that are either completely transmitted or weakly deflected by the sample This field is labelled Q1 for quadrant 1 There are two dark field c...

Page 19: ...TEM OUT button found in the STEM Control tool found in the docking side panel Section 1 4 1 If a normal SEM stage was used during the session completely lower the stage using the left control stick on the SEM Stage Control board Once the stage has been stowed the operator must lock the stage controls by enabling the Joystick Disable checkbox under the Stage tab This helps minimize the chance of so...

Page 20: ...r to reduce the rate at which the vacuum chamber soils Finally it is important to close the valves on the pressurized gas cylinders after venting the instrument This prolongs the lifetime of the tanks when the microscope is not in use 1 5 4 Closing the Software Given that user accounts are customizable and that user actions are logged it is important that operators log off their account or close t...

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Page 22: ...E detach or copy this cover and return to the address in the upper left hand corner Office of Research and Development 8101R Washington DC 20460 Official Business Penalty for Private Use 300 EPA 600 R 14 211 October 2014 www epa gov v Recycled Recyclable Printed with vegetable based ink on paper that contains a minimum of 50 post consumer fiber content processed chlorine free ...