OCI BDL800IR User manual

Chapter 1 Introduction 3
Foreword
The LEED Software Data Acquisition and Analysis was developed for OCI Vacuum Micro-
engineering by Dr. Greg Hall.
The software acquires, saves, and analyzes LEED images. The images areMultLEED
stores as platform independent bitmaps (.bmp files), which can be viewed using other Win-
dows applications. Supported platforms are Windows XP and Windows 7.
MultLEED can perform analyses on LEED images such as adding and subtracting im-
ages, enhancing brightness and contrast, line scanning through the image, calculating lattice
distances, calculating IV curves and reliability factor calculations, and acquiring Intensity–
Time (IT) curves.

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Chapter
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Introduction
Table of Contents
Foreword..............................................................................................................................3
Table of Contents..................................................................................................................4
1Introduction....................................................................................................................6
2Specifications..................................................................................................................7
2.1 LEED-AUGER Spectrometers Models BDL800IR, BDL600IR, and BDL450.....................7
2.2 Miniature Electron Gun Model G10...........................................................................8
2.3 PowerSupply Models LPS075-D and LPS300-D..........................................................8
3Installation....................................................................................................................11
3.1 Unpacking................................................................................................................11
3.2 Mounting.................................................................................................................11
3.3 Connecting ..............................................................................................................12
3.3.1 LEED Mode .......................................................................................................12
3.3.2 AES Mode .........................................................................................................12
4Electronics.....................................................................................................................15
4.1 LPS300-D and LPS075-D...........................................................................................15
4.1.1 Front Panel........................................................................................................15
4.1.2 RearPanel.........................................................................................................16
4.1.3 Electron Gun Pins Assignment...........................................................................17
4.2 LOA10-AES...............................................................................................................17
4.2.1 Detail Description .............................................................................................18
5Operating Instructions ..................................................................................................21
5.1 Getting Started........................................................................................................21
5.2 Quick Start...............................................................................................................22
5.2.1 Start-up.............................................................................................................22
5.2.2 Programming / Pre-Setting Parameters.............................................................22
5.2.3 Shutdown .........................................................................................................23
5.3 High Voltage Modules..............................................................................................23
5.4 Changing Operation Mode.......................................................................................23
5.5 Small Electron Beam Diameter.................................................................................23
5.6 AES Mode................................................................................................................23
5.6.1 Important..........................................................................................................24

Chap
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Introduction
5
5.6.2 Frequency Adjustment ......................................................................................24
5.7 LEED Mode ..............................................................................................................24
5.8 LPS300-D and LPS075-D...........................................................................................25
5.8.1 BasicOperation.................................................................................................25
5.8.2 Monitoring Beam Current..................................................................................26
5.8.3 Filament Forming..............................................................................................27
5.8.4 Filament Activation ...........................................................................................27
5.8.5 Outgassing.........................................................................................................27
6Programming Menu ......................................................................................................29
6.1 MenuItems .............................................................................................................29
6.2 MenuMap...............................................................................................................30
7Diagrams and Schematics..............................................................................................33
8Maintenance.................................................................................................................55
8.1 Cleaning Grids..........................................................................................................55
8.2 Filament Replacement.............................................................................................56
9Troubleshooting ............................................................................................................59
9.1 Bright or Dark Spots.................................................................................................59

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Chapter
1
Introduction
1Introduction
The Back-Display LEED-AUGER spectrometer is an instrument to measure the structure of
the first few atomic layers of crystalline surfaces based on the low energy electron diffraction
(LEED) effect. The spectrometer is also capable of measuring the elemental composition of a
surface via the analysis of Auger electrons. The basic instrument layout is a combination of a
hemispherical retarding-field analyzer, miniature electron gun, and a glass display.
The LEED technique has become an important experimental tool in the study of crystal
surface phenomena such as atomic structure of clean surfaces and chemisorbed layers, epi-
taxy, thermal etching, oxidation, phase transition, faceting, and many others. The AES tech-
nique is a major tool in materials research providing elemental surface analysis of surfaces
prepared by sputtering, annealing, deposition, etching, and others.
The Back-Display LEED-AUGER spectrometer is a compact instrument supplied in three
sizes. Model BDL800IR is adapted to fit an 8” CF flange, while model BDL600IR fits a 6”
CF flange and model BDL450 fits a 4.5” CF flange. The spectrometer optics comprises a set
of grids, a transparent screen coated with a P31 phosphor and conducting coating, and a min-
iature coaxially mounted electron gun. Units can optionally be equipped with a linear motion.
Digital LEED-AES power supply/controller, model LPS300-D, is designed to control all
models of INTEGRALEED optics in the LEED mode with a beam energy range of 5–750 eV
and in the AES mode with a beam energy range of 5–3000 eV. The controller is using on-
board microprocessor to execute programs and optical rotary encoders for settings. Models
LPS300-D and LOA10-AES constitute a complete analytical package for both LEED and
AES. Model LPS075-D operates in LEED mode only.
The High Voltage Generator supplies a sweep voltage modulated with a sine wave. The
unit comprises a precision oscillator, which delivers Vpp up to 20 V. The generator is con-
trolled by the AES software installed on a PC via USB.
The Low-noise Input Coupler provides 160–180 V biasing of the screen collector, band-
pass filtering, and signal pre-amplification.

Chapter
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Specifications
7
2Specifications
2.1 LEED-AUGER Spectrometers Models
BDL800IR, BDL600IR, and BDL450
Mounting to Vacuum Chamber Double-sided CF flange of size:
BDL800IR 8” with M8 (5/16-24) threaded holes
BDL600IR 6” with M8 (5/16-24) threaded holes
BDL450 4.5” with M8 clearance holes
Sample distance must be specified by th
e user and may
range from 145–500 mm (580 mm for BDL450).
Monitoring Standard viewport of size:
BDL800IR 8”
BDL600IR 6”
BDL450 4.5”
Linear Motion (optional) Retraction of up to 150 mm (100 mm standard) from a sam-
ple.
Integral Shutter (optional) Manual shutter driven by a rotary feedthrough.
Glass-display Fused silica coated with indium-
tin oxide and P31 phosphor
(ZnS:Ag:Cu–= 525 nm).
Angle of Acceptance BDL800IR 100° at a sample distance of 75 mm
BDL600IR 90° at a sample distance of 51 mm
BDL450 90° at a sample distance of 32 mm
Retarding Field Analyzer Concentric 4-grid assembly with analyzer working distance:
BDL800IR 18 mm
BDL600IR 15 mm
BDL450 10 mm
Grid Material Gold-coated tungsten wire mesh with 81% transmission.
Baking Conditions Under vacuum, maximum 250°C.

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Chapter
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Specifications
2.2 Miniature Electron Gun Model G10
Beam Energy LEED: 5 to 750 eV
AES: 5 to 3000 eV
Beam Current LEED: 2 μA at 100 eV
AES: up to 100 μAat 3 keV
Beam Size
Adjusted by a potential of the Wehnelt cylinder typically
ranging from 1 mm to 250 μm, minimum of 50 μm
using an
exchangeable aperture.
Electron Source Thoriated (2%) tungsten filament (standard)
or directly
heated LaB6single crystal.
Dimensions Lens diameter of 10 mm and 80 mm in length.
2.3 Power Supply Models LPS075-D and
LPS300-D
Beam Voltage LPS075-D: negative 0–750 V
LPS300-D: negative 0–3000 V
Filament Current 0–3.2 A
Wehnelt Voltage 0–37 V with respect to the filament
Focus Voltage LEED: positive 70–180% of the beam voltage
AES: negative 0–3000 V
Retarding Voltage
Negative 50
–110% of the beam voltage
Screen Voltage Positive 0–5000 V
Emission Current 1–200 μA
Beam Current 0.01–200 μA
Monitoring All voltages and currents.
Display Vacuum fluorescent, displaying all voltages, currents, and
program functions.
On-Board Automation 5 pre-programmed and fully programmable operating pro-
grams for outgassing, stand-by, filament forming, beam

Chapter
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Specifications
9
voltage scanning, constant beam current, and diagnostics.
Manual Control Of all voltages via rotary dials and selection switches.
PC Control PC software for full control of all functions via USB.
Protection Over-voltage, over-current, and short circuit.
Dimensions 3U 19” rack mount (5.25” / 133 mm), depth of 17.5”
(440 mm), weight 12 kg.

Chapter 3 Installation 11
3Installation
WARNING: HIGH VOLTAGES EXIST IN VARIOUS PARTS OF THIS IN-
STRUMENT.
SPECIAL CARE SHOULD BE EXERCISED WHEN OPERATING WITH THE
PROTECTIVE COVERS REMOVED!
CAUTION: THE INSTRUMENT IS FRAGILE AND MUST BE HANDLED
BY PERSONNEL TRAINED FOR ULTRA HIGH VACUUM ON-
LY!
3.1 Unpacking
Please check for any signs of physical damage, which may have occurred during shipment. If
any damage is found, contact your shipping agent immediately. Otherwise, you may unpack
the equipment.
The LEED-AUGER optics has been shipped enclosed in a protective and clean alumini-
um container under argon atmosphere. Carefully remove the cover and check the optics for
obvious loose connections, electrical shorts, or damage. Install the optics inside a vacuum
chamber as soon as possible after opening.
3.2 Mounting
The LEED-AUGER optics resides on a double-sided 8” (BDL800) or 6” (BDL600) CF
flange. A proper seal can be made using either a copper gasket or an appropriate rubber or
Viton gasket depending on the nature of the vacuum system application. The instrument may
be operated in any position, however, the horizontal position is recommended when the op-
tional linear motion mechanism is installed. See Section (TODO add) for optimum position
with respect to stray magnetic fields.

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Installation
3.3 Connecting
3.3.1 LEED Mode
Make sure to follow all steps below (see the diagram on pages 15 and 16 for details):
Install a power supply into a rack and make room at least 5 cm (2”) below and
above to allow for air circulation through the case.
Check the voltage label on the rear panel and match the input voltage level.
Check that a correct fuse is installed. If necessary, replace it.
Ensure that the power switch is in the OFF position.
Plug the electron gun cable into a LEED/AES OUTPUT socket on the power
supply and into an E-GUN port on the LEED-AUGER optics. At the same time
plug the high-voltage cable in a Grid 2&3 BNC connector.
Bridge the SCREEN BNC connectors of the optics and the power supply.
Plug in a power cord. The instrument is now ready for operation.
3.3.2 AES Mode
Make sure to follow all steps below (see the diagram on pages 15 and 16 for details):
Install a power supply into a rack and make room below and above to allow for air
circulation through the case.
Install a lock-in amplifier LOA10-AES into a rack and connect it to your PC using
a USB cable.
Check the voltage label on the rear panel and match the input voltage level.
Check that a correct fuse is installed. If necessary, replace it.
Ensure that the power switch is in the OFF position.
Plug the electron gun cable into a LEED/AES OUTPUT socket on the power
supply and into an E-GUN port on the LEED-AUGER optics. Leave the high-
voltage cable Grid 2&3 disconnected.
Connect the Input Coupler’s INPUT SIGNAL–COLLECTOR port to the
SCREEN connector of the optics using a BNC adapter.
Connect the Input Coupler’s BIAS VOLT IN port to the SCREEN connector
of the LPS300-D.
Connect the Input Coupler’s DC IN port to the PRE-AMP DB9 connector of the
LOA10-AES.
Connect the Input Coupler OUTPUT TO LOCK-IN to the INPUT of the
LOA10-AES. Caution: Do this only with the AES software running to avoid over-
loading of the lock-in input.

Chapter
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Installation
13
Connect the LOA10-AES’s GRID 2&3 port to the GRID 2&3 of the optics
using a MHV BNC terminated cable.
Plug in a power cord. The instrument is now ready for operation.

Chapter 4 Electronics 15
4Electronics
4.1 LPS300-D and LPS075-D
Model LPS300-D is designed to control LEED-AES spectrometers in both LEED and AES
regimes. It can be controlled manually using the front panel controls or remotely via USB
using a software program.
Model LPS075-D is designed to control LEED-AES spectrometers in the LEED mode
only. It can be controlled manually using the front panel controls or remotely via USB using
a software program.
The main board consists of analogue controls, power supplies, and high voltage modules.
The high voltage section is optically isolated from the digital electronics. Beam current is
obtained indirectly by measuring current returning through ground.
All currents and voltages are measured at the output, which allows to continually monitor
the LEED-AES operating conditions.
4.1.1 Front Panel
Selectors / Buttons Description
Instrument Mode Select the main operating regime—LEED or AES (LPS300-
D).
Controller Mode Select the controller mode—Operation, Programming, and
Test.
Program Selection Press the selector to display a menu. Rotate the selector to

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Chapter
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Electronics
highlight a desired program and press
Select
to confirm.
The Save button saves the current displayed voltages and
the filament current.
Filament, Wehnelt, Focus,
Grid2&3, and Screen Select any of these to be set by the Beam Energy Control knob.
Beam Energy Control Turn knob to change value of the selected variable (see
above). If none of the above variables are selected, beam
energy will be changed. Press the knob to (de)activate a
beam energy ramp.
Filament On/Off Turn filament current on and set it to a pre-set value, or turn
it off.
Screen On/Off Turn screen voltage on and set it to a pre-
set value, or turn it
off.
Constant Beam Current On/Off
Shut Down
Turn constant current mode on/off. The controller will au-
tomatically adjust either the filament current or the Wehnelt
voltage to keep the beam current constant with a value tak-
en at the time when it was turned on.
Press and hold > 2 s to soft shutdown the unit.
4.1.2 Rear Panel
Element Description
Beam Energy Remote Control
DB9 connector for remotely controlling beam
energy in the LEED mode.
USB Connection USB port
used to remotely control the unit

Chapter
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Electronics
17
using a PC.
GND Separate ground terminal.
Fuse 2 A slow blow fuse rated for 100–120
V, or
1.5 A slow blow fuse rated for 220–240 V.
AC In AC input power 3-pole socket.
Screen BNC connector, maximum 5 kV DC.
LEED/AES Output 12-
pin connector for the electron gun cable.
Configuration of the pins partially differs be-
tween LEED and AES modes.
4.1.3 Electron Gun Pins Assignment
LEED Mode AES Mode
A Filament A Filament
B Filament B Filament
C Wehnelt C Wehnelt
D Common D Focus
F Focus F Common / Resistor Bias
G Common G Common
M Ground (Cable shielding) M Ground (Cable shielding)
J Grid 2&3
4.2 LOA10-AES
Model LOA10-AES is a dedicated controller allowing the INTEGRALEED optics perform-
ing Auger Electron Spectroscopy using Retarding Field Analyzer. This unit can also be used
in conjunction with other types of analyzers, such as Cylindrical Mass Analyzer. The unit
consists of a high voltage ramp, a precision sine wave generator, a lock-in amplifier, and a
low noise input coupler with a preamplifier.
All functions of this unit are controlled remotely by our AES software via the USB.
The high voltage ramp supplies a sine wave modulated output signal. The unit comprises
a precision sine wave oscillator with a maximum Vpp of 20 V. Its frequency can adjusted in
the range of ±5% by a trimmer located on the front panel.

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Chapter
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Electronics
A lock-in amplifier for phase sensitive detection is built into this unit. It consists of one
phase-locked loop (PLL), one phase sensitive detector (PSD), two single-ended analog-to-
digital converters (ADC), and two digital-to-analog converters (DAC). Also available are
four lines for digital input and four lines for digital output. The PLL can be set to lock either
on the fundamental or the second harmonic.
Sensitivity, time constant, and phase are controlled externally by the AES software. The
phase can be adjusted to 90° or 180°.
4.2.1 Detail Description
High Voltage Ramp Generator
Sweep Generator Sweep Voltage 0–2000 V
Sweep Rate AES software controlled (16-bit DAC)
Sweep Voltage Offset
(start) AES software controlled (16-bit DAC)
Sweep Voltage Offset
(end) AES software controlled (16-bit DAC)
Ramp Voltage Moni-
tor AES software controlled (16-bit DAC)
Internal Oscillator and
Modulator Frequency Fixed at 1.457 kHz, trimmer adjusted ±5%
Amplitude (peak-to-
peak) Regulated from 0.5 to 20 V (16-bit DAC)
Distortion Harmonic 0.1%
Noise 50 μV RMS
PSD Type Switching multiplier
Input Impedance AC coupled, 100 nF into 1 MΩ
Input True differential
AC Gain
10, 100, 1000, 10000 (and 1, 2, 4, 8) software
selectable
Interstage Coupling Simple high pass typically with 3 dB per
72 Hz
Post Detection Low
Pass Filter Equal component Sallen-Key, 2nd order with a time constant of 0.1, 0.5, 1, and 3 s
Signal Channel
Equivalent Input Typically less than 20 nV/Hz at 1 kHz

Chapter
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Electronics
19
Noise
PLL Input Impedance AC coupled, 10 nF into 1 MΩ
Frequency Range 0.2–7.5 kHz with a typical phase jitter
< 0.2%
Locks Onto The fundamental or 2nd harmonic
ADC Chip TI ADS7807
Resolution 16 bits
Accuracy ±1.5 LSB max INL
Conversion Time 25 μs
DAC Chip TI DAC715
Resolution 16 bits
Settling Time 3 μs
Channels 1
Computer Interface USB
Software AES data acquisition and analysis software for Windows XP/7
Dimensions 2U 19” rack mount (3.5” / 89 mm), depth of 13.5” (343 mm), weight
6 kg.
Low Noise Input Coupler Model AUS30
Input Impedance 10 MΩ (internal bandpass filter)
Amplifier FET input, 500 gain
Dimensions 180 mm × 105 mm × 65 mm
Low Noise Bandpass
Filter Central Frequency 2.95 kHz
3 dB Band Width 200 Hz
20 dB Band Width 7.83 kHz