User Manual for JSM-6400 (SEM)
(This is an informative purpose only. Do not attempt to operate the SEM without superuser permission or having a sertification)
I) INTRODUCTION
II) PRE-USE CHECKS
III) KEYBOARD AND ON-SCREEN MENUS
Introduction
Computer Keyboard
Basic Screen
Electron Operating System (EOS) Menu
EOS screens
EOS-1 (OPTICS)
EOS-2 (MODE)
EOS-3 (IMAGE)
MEMO Menu
IV) SYSTEM OPERATION
Sample Preparation
Loading the Sample and Pumpdown (2” Airlock)
Turning on the Beam
Aligning the Beam
Viewing the Sample
Taking a Picture
Turning Off the Beam
I) Introduction
The JEOL 6400 scanning electron microscope (SEM) is a high-resolution SEM. It can
provide beam voltages ranging from 0.2kV to 40 kV and beam currents from 10
picoamps to 10microamps. It offers high performance and low noise at low accelerator
voltages. Resolution of 10 nm is attainable, and available magnifications range from 10
X to 300,000 X. The cathode is a tungsten hair pin filament. The SEM is equipped with
a two-inch airlock and a probe current detector (PCD) or Faraday cup for beam current
measurements. The sample stage is computer-driven.
II) Pre-Use Checks
When not in use, the JEOL 6400 is normally left with the high voltage turned off Note
that all the controls required for standard sample observation are described below.
Under no circumstances should users operate any other controls without first consulting
staff. This includes the entirety of the vacuum system, with the exception of the sample
airlocks.
Prior to using the SEM you should check that all is in order.
• Verify that the filament knob is turned fully counter-clockwise and that the filament
meter light is on. The filament button FIL toggles the meter between filament and
emission current measurement. If FIL is not lit, you are looking at the emission
current and should toggle to FIL; the meter should then read ~1.0 A.
• If the meter light is not on, the gun pressure is not acceptable. If both FIL and the
meter light are lit but there is no filament current, the SEM is not usable. Report the
problem on the Comments section of the logbook AND to Murat Güre.
• Check that the accelerating voltage is set to 0 kV and the secondary electron
detector is off using the EOS menu (see Section 3.3).
III) Keyboard and On-screen Menus
Introduction
Most of the functions of the JEOL 6400 can be accessed though keyboard and menu
operations. This includes most of the knob and button controls, with a few exceptions
(e.g., the filament current knob). In addition, much of the fine-tuning required for
successful imaging can only be accomplished using keyboard control. The various
menus through which control takes place are displayed only on the right-hand (RH)
CRT. The left-hand (LH) CRT is used primarily for viewing. A cursor is displayed on
one of the two CRTs at a time; the CRT in which the cursor appears is active. The
cursor can be toggled back and forth between the two CRTs by pressing the escape
(ESC) key.
Computer Keyboard
The most useful keys are escape (ESC) mentioned above, BREAK, the return key,
and some of the pre-defined function (PF) keys. Also useful are insert (INS), and the
plus (+) and minus (-) keys. Uses of these keys will be described below.
6400 keyboard
6400 panel controls
6400 knobset
Basic Screen
The basic screen is always displayed on the LH CRT; it is also displayed on the RH CRT
when the menus are hidden. This screen consists of two information lines customarily
located at the bottom of the screen. When a given CRT is active (i.e. the cursor is in it)
and is displaying the basic screen, its information lines can be alternately shown or
hidden by pressing the BREAK key. The information displayed in the lines includes a
micron bar and size, a title, the accelerating voltage, the magnification and the working
distance.
The pre-defined function key PF1 brings up the basic screen on the RH CRT regardless
of which screen is active.
Electron Operating System (EOS) Menu
PF2 brings up the EOS menu on the RH CRT regardless of which screen is active. The
EOS menu consists of three screens: EOS-1 (optics), EOS-2 (mode) and EOS-3
(image). When the RH CRT is active and EOS is displayed, pressing the 1, 2, or 3 keys
will call up the corresponding screen.
Most of the SEM functions required for viewing can be controlled though the EOS menu.
To change a parameter, make the RH CRT active using the ESC key. If the item you
want to change displays a set of possible choices (e.g. the raster scan speed), position
the cursor over your choice using the arrow keys. Then press the return key to select the
item. If instead the item is numeric (e.g. the accelerating voltage), position the cursor
over the number and press the INS key. A white command window will appear on the
RH CRT. Enter the new setting and press return to make a change. You can also
increment or decrement a numeric setting by positioning the cursor over it and pressing
the + or - keys.
EOS screens
The following is a brief description of the contents of the three EOS screens. Ranges
are shown for numeric items when appropriate. Standard settings of the other items are
indicated by asterisks. When control over an item is not needed for basic use, only the
standard setting of that function is listed. Settings not needed for basic use are not
listed, and should not be used without consulting staff. Settings which should not be
changed without permission are indicated in the following list:
EOS-1 (OPTICS)
• ACC VOLTAGE: accelerator voltage, 0 to 40 kV
• BIAS: bias resistor setting; default for given ACC setting shown in parentheses is
recommended, 0 to 6
• TILT/SHIFT: gun tilt and shift, X and Y for each: -128 to 127
• CL: condenser lens; controls beam current, COARSE: 0 to 16; FINE: 0 to 255
• OL: objective lens, controls focus, COARSE: 0 to 255; FINE: 0 to 1023
• WD: indicates distance from plane of OL to focused point, 3 to 53 mm.
• STIGMA: astigmatism adjust, X and Y: -512 to 511. This should be below 100 when
the image is fine-tuned. Higher readings indicate misalignment of the beam or need
• of column cleaning. Good patterns will not be obtainable.
• MAG: magnification, 10X to 300,000X
• INST MAG: switches to a pre-defined magnification, *OFF*
• SEI: CONT 0 - 255 adjusts contrast of SEI image. Bright 0 - 255 adjusts brightness
of SEI image
• PCD: probe current detector, on this SEM, can only be operated via PCD button in
one of the auxiliary panels
• LENS CLEAR: removes hysteresis in objective and/or condenser lenses, ALL, OL,
CL
• OPT APERT: optimum aperture for present settings; not operated via keyboard: 2 to
4 (only a recommendation, choice is up to operator)
EOS-2 (MODE)
• EOS MODE: chooses operating mode of SEM; use only SEM or SEM1: *SEM*,
SEM1
• SCAN MODE: chooses scan mode; PIC and LSP most useful: *PIC* (picture), RD2,
RD4 (reduced scan), LSP (line scan)
• SPEED: selects scan rate; TV and SR are fast, others are slow: *TV*, SR, 2, 10, 20,
40 , 80, 80, 320, 640
• POSITION: adjusts position of reduced and line scans, X, Y: -128 to 127, zero
these before alignment or writing. SEM1 mode will disable these drives.
• WIDTH: adjusts width of reduced scan, X, Y: 26 to 255
• IMAGE SHIFT: induces static shifts in the sample image, X, Y: -128 to 127
• DSPL MODE: chooses display mode; NOR, DMG and WFM most useful; YZM
should normally be off
• DFC: dynamic focus mode, *OFF*
• PHOTO SPEED: selects photo speed, 40, *80*, 80, 320, 640
EOS-3 (IMAGE)
• DETECTOR: actives/deactivates secondary electron detector; USE ONLY SEI:
OFF, *SEI*
• COLLECTOR: controls application of voltage to collector of secondary electron
detector, *ON*
• PMT LINK: links photomultiplier tube to setting, *ON*
• IMS CH1: chooses image source for channel one; USE ONLY SEI:
• *SEI*
• INPUT: DIG, *ANA*
• POLARITY: *NOR*
• GAIN: *128*
• BRIGHT: *128*
• IMS CH2: see IMS CH1
• MIX: when on allows mixing of CH1 and CH2 signals; when off CH1 only is
displayed, *OFF*
MEMO Menu
The MEMO menu is called up by pressing the PF5 key. This menu lists ten sets of predefined
operating conditions; the chosen settings for various SEM parameters are listed
in the lower half of the screen. To load the selected set of operating conditions, select
the title of the set in the upper half of the screen using the arrow keys. Then press "L"
for load. The listed set of conditions will immediately be loaded into the SEM.
NOTE: loading a set of operating conditions will result in immediate application of an
accelerating voltage! DO NOT load a set unless you are ready for the listed conditions
to come into effect immediately. See Section 4: System Operation below.
Do not change the contents of any of the pre-defined states; they are provided for the
convenience of all users.
IV) System Operation
Checklist of Procedures
Follow the steps outlined below to get an image on the SEM. More information on each step is
provided in the following pages.
A) Sign logbook.
B) Prepare your specimen for insertion into the SEM.
C) Verify that the ebeam system cable is un-pluged.
D) Insert the specimen into the sample chamber of the SEM.
E) Perform the initial setup of all switches on the SEM console.
F) Saturate the Filament.
G) Adjust the Gun Shift & Tilt - resaturate if necessary.
H) Adjust the contrast and brightness.
I) Focus the image.
J) Stigmate the image.
K) Record a micrograph if desired.
L) Perform microanalysis if desired.
M) Shut down SEM when done.
N) Remove specimen.
O) Sign logbook.
Sample Preparation
Samples can be most sizes or shapes as long as they can be loaded through the 2”
sample exchange port. Commonly, 1” or 1.25” metallographic preparations will be
examined in the SEM. Samples must be clean and dry, i.e., free from moisture, oils,
grease, and particles that could the vacuum system. If the chamber becomes
contaminated, the contaminants can be "ironed on" to your sample by the beam. Once
this happens, it is usually impossible to remove the contaminants from your sample.
Gloves must be worn when handling samples and sample holders. Note that
nonconductive materials are subject to "charging" and for best results should be coated
with a thin layer of gold. For cross-sections, cleave the sample through the area of
interest. The sample should be as small as possible, but large enough that it can be
securely held by the sample holder. If the sample is to be coated with gold, it should be
coated after cleaving. For cross-sections, use the spring loaded sample holder for
securing the sample. The "Z" axis knob on the stage is calculated from the sample
holder top. If the sample must be secured to the holder, use SEM-compatible (vacuum
compatible and conductive) carbon paint. Write Murat Güre () if you
have questions about SEM compatible adhesive. After attaching or securing your
sample to the sample holder, the sample holder is mounted into the larger dovetail
holder. This dovetail holder will slide or "dovetail" over the stage in the SEM chamber.
For cleaved cross-sections, it is recommended that you mount the sample so that the
cleaved edge is parallel to the longer side of the dovetail holder.
Loading the Sample and Pumpdown (2 Inch Airlock)
1) The sample is loaded using a threaded rod; this rod is mounted through the center of
a thick, circular viewport. The viewport allows you to visually guide the dovetail
holder onto the stage and visually assess the orientation of the sample for tilt and
rotation before viewing on-screen, where orientation is not as obvious.
2) Thread the screw at the end of the sample loading rod into the bottom hole of the
dovetail holder, and hook the clip attached to the viewport over the screw. The clip
secures the sample holder to the viewport until you are ready to move it onto the
stage; if you don't use the clip, the sample and rod will move forward into the door,
possibly damaging your sample or the door! If the rod does not easily slide through
the viewport vacuum seal, apply grease to the rod sparingly.
3) Verify that the working distance (Z height) is set to the specimen exchange distance
of 39mm; the red light on the front of the airlock exchange panel will come on to
indicate that the working distance is correctly set to 39mm. Also check that the fine
Z micrometer is set to 2.0 mm; it is located between the X and Y micrometers.
4) Set the stage to its home position (250 on the X and 350 on the Y travel counter). Manually adjust the rotation (angular and circular) counters to zero. Warning: Any operations on the optics table must be done gently, without disturbing the table.
5) Check the viewport and airlock o-ring for dust, remove dust to make a good seal.
Hold the viewport with the sample facing towards the SEM chamber against the oring
seal at the two-inch airlock entrance. Press the illuminated white button on the
airlock chamber and wait for the light to go out. The light is on a timer and should
allow enough time for the chamber to evacuate. Improper evacuation of the airlock
can cause the vacuum system to “dump” when you open the airlock door resulting in
down time!
6) When the light goes out, open the airlock door by rotating the airlock knob towards
you 1/4 of a turn. Slide the door open by pulling the knob to the right, about 3". Be
gentle. There is a clip in the airlock for this. Do not lock it with the knob as it will get
debris on the door o-ring. The light in the SEM chamber should come on when you
open this door. If the light is off, then the secondary electron detector is on. To turn