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
1
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
2
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
2
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
2
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.