NT-MDT NTEGRA Spectra User manual

NTEGRA Spectra

(Inverted Configuration

with Renishaw Spectrometer)

Instruction Manual

12 April 2010

Web Page: http://www.ntmdt.com

General Information: [email protected]

Technical Support: [email protected]

NT-MDT Co., building 100,

Zelenograd, 124482, Moscow, Russia

Tel.: +7 499-735-7777

Fax: +7 499-735-6410

Read me First!

Observe safety measures for operation with devices containing sources of laser radiation.

Do not stare into the beam. A label warning about the presence of laser radiation is

attached to the measuring head (Fig. 1) as well as to the laser sources.

Fig. 1

Before you start working with the instrument, get acquainted with the basic safety

measures and the operation conditions for the instrument!

If you are a beginner in scanning probe microscopy, we recommend you to familiarize with

basic SPM techniques. “Fundamentals of Scanning Probe Microscopy” by V.L. Mironov

gives a good introduction to the subject. This book is available on the Internet,

http://www.ntmdt.com/manuals.

Feedback

Should you have any questions, which are not explained in the manuals, please contact

the Service Department of the company ([email protected]) and our engineers will

give you comprehensive answers. Alternatively, you can contact our staff on-line using

the ask_on-line service.

User’s documentation set

The following manuals are included into the user’s documentation set:

− Instruction Manual – is the guidance on preparation of the instrument and other

equipment for operation on various techniques of Scanning Probe Microscopy. The

contents of the user’s documentation set may differ depending on the delivery set of

the instrument.

− SPM Software Reference Manual – is the description of the control program

interface functions, all commands and functions of the menu and, also a description of

the Image Analysis module and the Macro Language “Nova PowerScript”.

− Control Electronics. Reference Manual – is the guide to SPM controller,

Thermocontroller and Signal Access module.

Some equipment, which is described in the manuals, may not be included into your

delivery set. Read the specification of your contract for more information.

The manuals are updated regularly. Their latest versions can be found in the site of the

company, in the section “Customer support” (http://www.ntmdt.com/support).

NTEGRA Spectra Probe NanoLaboratory. (Inverted Configuration with Renishaw Spectrometer).

NTEGRA Spectra PNL (Inverted Configuration with

Renishaw Spectrometer)

Table of Contents

1. OVERVIEW ............................................................................................................................................. 5

2. DESIGN..................................................................................................................................................... 7

2.1. INVERTED MEASURING UNIT............................................................................................................ 8

2.1.1. Inverted Optical Microscope.............................................................................................8

2.1.2. NTEGRA Base Unit...........................................................................................................9

2.1.3. XY Scanning Optical Exchangeable Mount.....................................................................10

2.1.4. Measuring Heads.............................................................................................................12

2.1.5. Additional Cables............................................................................................................16

2.2. DETECTORS .................................................................................................................................... 18

2.3. CONTROLLERS ................................................................................................................................18

2.4. COMPUTER ..................................................................................................................................... 19

3. BASIC SAFETY MEASURES .............................................................................................................. 20

4. OPERATING CONDITIONS ............................................................................................................... 22

5. STORAGE AND TRANSPORT REGULATION ............................................................................... 24

6. GENERAL REQUIREMENTS ON INSTALLATION ...................................................................... 25

7. SETUP AND INSTALLATION ............................................................................................................ 26

7.1. CONNECTING THE ELECTROMECHANICAL UNITS............................................................................ 26

7.2. POWERING SEQUENCE .................................................................................................................... 28

8. PREPARING FOR OPERATION........................................................................................................ 30

8.1. SWITCHING ON THE INSTRUMENT ................................................................................................... 30

8.2. VERIFYING ADJUSTMENT OF THE DISPLACEMENT SENSORS........................................................... 30

8.3. MOUNTING THE SAMPLE ................................................................................................................ 31

9. MEASURING WITH THE CONFOCAL MICROSCOPY MODE .................................................. 32

9.1. CONFIGURING THE INSTRUMENT .................................................................................................... 32

9.2. APPROACHING THE SAMPLE AND FOCUSING THE LASER BEAM...................................................... 33

9.3. ADJUSTING CHANNELS OF DETECTION ........................................................................................... 34

9.3.1. Adjusting Signal Detection with the Andor CCD Camera...............................................34

9.3.2. Adjusting Signal Detection with the Renishaw CCD camera..........................................37

9.4. ADJUSTING SCAN PARAMETERS ..................................................................................................... 39

9.5. ADDITIONAL ADJUSTING FOR SCANNING WITH AFM HEAD ........................................................... 40

9.6. SCANNING ...................................................................................................................................... 46

9.7. SAVING DATA................................................................................................................................. 49

9.8. FINISHING THE WORK..................................................................................................................... 49

10. OTHER CAPABILITIES ...................................................................................................................... 51

10.1. AFM MEASUREMENTS ................................................................................................................... 51

10.2. SNOM MEASUREMENTS ................................................................................................................ 51

4

Chapter 1. Overview

1. Overview

NTEGRA Spectra PNL combines measurement capabilities of spectrometry, SNOM and

AFM, which are enhanced by SNOM-spectrometry and AFM-spectrometry.

Theses capabilities are illustrated by the conceptual scheme of Fig. 1-1.

Fig. 1-1. Conceptual scheme of the NTEGRA Spectra PNL

The spectrometer is based on the infinity-corrected confocal optical scheme that provides

submicron spatial resolution (200÷300 nm in the lateral (XY) and 500÷700 nm in the

normal (Z) directions). High spectral resolution (several tenths of angstrom) is achieved

due to the Czerny-Turner optical schematics of the spectrometer. For excitation of

secondary emission, a gas or solid-state laser is employed. The spatial (XYZ) information

is acquired with a special scanning system. A more detailed description of the instrument is

provided below.

NTEGRA Spectra PNL provides the following options of measurements:

− performing spectral measurements at a certain point and acquiring spectral

characteristics of various materials when the instrument operates as a regular

spectrometer;

− measuring secondary signal intensity in the selected wavelength range in the mode of

layer-specific volumetric scanning of the area 100x100x30 μm;

− acquiring optical images of the object when the instrument operates as a regular laser

confocal microscope.

5

NTEGRA Spectra Probe NanoLaboratory. (Inverted Configuration with Renishaw Spectrometer).

6

In addition to measurements, the NTEGRA Spectra PNL facilitates to perform volumetric

lithography.

The SNOM-Spectrometer configuration allows the following:

− measuring surface topography with the Shear Force Microscopy;

− in the transmission mode, measuring optical and spectral properties of the object with

the resolution achievable by the Scanning Near-field Optical Microscopy.

The AFM-Spectrometer configuration allows the following:

− detecting the object landscape with atomic resolution as well as collecting its

electrical, magnetic and nanomechanical properties with force microscopy techniques;

− measuring optical properties relevant to the Scanning Near-Field Optical Microscopy

in scales down to atomic sizes.

The NTEGRA Spectra PNL application area includes technology processes control in

chemical, food and medicine industries, environment monitoring, isotope composition

analysis, defects control, control of impurities in pure substances, analysis of materials of

quantum electronics and semiconductor industry, fundamental research in physics,

chemistry, medicine etc.

The instrument layout is quite flexible for the experimenter to change the configuration

with units designed especially for a given purpose. The software is advanced to facilitate:

− performing spectral measurements;

− controlling the scanning mechanism, the automated optical mechanical units, the light

detection systems (CCD camera and APD module);

− displaying 3D data, filtering, analysis and saving the collected data.

Chapter 2. Design

2. Design

Fig. 2-1 shows general view of the NTEGRA Spectra PNL instrument.

Fig. 2-1. NTEGRA Spectra PNL

NTEGRA Spectra PNL consists of the following main parts:

− Inverted measuring unit:

- Inverted optical microscope Olympus IX71;

- Base unit of NTEGRA;

- XY scanning optical exchangeable mount.

- Measuring heads:

- SNOM;

- AFM.

− Podule measuring unit (For details, please, refer to Renishaw user’s manual).

− Spectral unit (For details, please, refer to Renishaw user’s manual):

- Spectrometer;

- Laser.

7

NTEGRA Spectra Probe NanoLaboratory. (Inverted Configuration with Renishaw Spectrometer).

− Detectors:

- Renishaw CCD camera;

- Andor CCD camera (availability depends on the delivery set).

− Optical viewing system.

− Control system:

- Main SPM controller;

- Slave SPM controller;

- Computer.

2.1. Inverted Measuring Unit

2.1.1. Inverted Optical Microscope

An inverted optical microscope Olympus IX71 (Fig. 2-2) serves for taking common optical

images. The base unit of the instrument is mounted on it.

Fig. 2-2. Inverted optical microscope Olympus IX71

8

Chapter 2. Design

The microscope is equipped with an optical system that provides the following options for

NTEGRA Spectra:

− delivering laser beam to the sample;

− delivering the light reflected from the sample to the spectrometer;

− monitoring the process of approaching the lens to the sample;

− displaying the sample image taken from the video camera of the microscope.

2.1.2. NTEGRA Base Unit

The base unit of NTEGRA (Fig. 2-3) is the base platform for mounting the exchangeable

mount and the protective hood.

Fig. 2-3. Main components of the base unit

1 – approach lever; 2 – manual approach knob;

3 – temperature and humidity sensor; 4 – LC-display

The base unit includes the approach system that is used to approach the lens to the sample.

For manual operation, the manual approach knob 2 is used.

Data on ambient temperature and humidity are measured with the sensor 3 and then

displayed by the LC-display 4.

Base unit electrical slots

Slots for connecting the devices installed on the base unit:

HEAD – two identical connectors for connecting the measuring head;

SCANNER – scanner connector, used for connecting either the exchangeable

scanner or the measuring head scanner;

9

NTEGRA Spectra Probe NanoLaboratory. (Inverted Configuration with Renishaw Spectrometer).

SCAN+SENSOR – connector for the scanner or for the scanner with built-in sensors,

used for connecting either the exchangeable scanner or the measuring

head scanner;

Т –connector of a heating element, used for connecting a heating stage, heating

liquid cells etc.;

SM – connector of the stepper motor;

AFAM – connector of the ultrasonic piezoelectric transducer;

BV – bias voltage jack, used for applying bias voltage to the sample.

Slots for connecting the bias unit to the control system:

CONTROLLER 1 – connector for connecting to the HEAD connector of the SPM

controller;

CONTROLLER 2 – connector for connecting to the CONTROLLER 2 connector of the

SPM controller;

CONTROLLER T – connector for connecting to the thermocontroller.

2.1.3. XY Scanning Optical Exchangeable Mount

XY Scanning Optical Exchangeable Mount (Fig. 2-4) allows:

− manual positioning of the measuring head in the XY plane;

− manual positioning of the sample by means of micrometer screws;

− precise positioning of the sample by means of the built-in XY scanner;

− manual approaching the lens to the sample by means of a stepper motor;

− fine focusing by means of the Z piezo drive of the lens.

The XY Scanning Optical Exchangeable Mount holds the investigated sample, the

measuring head, and the lens of the inverted optical microscope.

A substrate with a mounted sample is fastened to the sample stage 4 with the spring clips 5.

The seats 1 of the exchangeable mount hold the measuring head. Positioning of the

measuring head with respect to the lens is performed by means of screws 2. To select the

scan area, the sample is moved using the micrometer screws 3 of the XY positioning

device and inspected with the optical viewing system.

10

Chapter 2. Design

Fig. 2-4 XY Scanning Optical Exchangeable Mount

1 – measuring head seats; 2 – measuring head positioning screws;

3 – XY positioning device micrometer screws; 4 – sample stage;

5 – spring clips; 6 – scanning platform

The scanning platform 6 serves to move the investigated sample in the process of XY

scanning. It provides scanning in the wide range, high positioning precision and high

linearity of the sample displacement. Linearity of scanning with this platform is better than

that of scanning with the measuring head. Furthermore, during SNOM measurements, it

allows to keep the area under investigation within the lens focus.

The lens is mounted into the “cup” (Fig. 2-5) inside the exchangeable mount. The “cup” is

designed to approach the lens to the sample with the manual approach knob

(see 2 on Fig. 2-3). As well, it is equipped with a piezoelectric element for fine focusing

the lens on the sample and for Z-scanning.

Fig. 2-5. Inside “cup”

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NTEGRA Spectra Probe NanoLaboratory. (Inverted Configuration with Renishaw Spectrometer).

Exchangeable mount technical specifications:

Measuring head travel, XY 55 mm

XY positioning device travel 55 mm

XY positioning device translation resolution 5 µm

Scanning range, XY 100100 µm

Lens focus range, Z piezo drive 50 µm

 NOTE. XY scanning range of the scanning optical mount can be 50



50 µm

depending on the delivery set.

2.1.4. Measuring Heads

Scanning probe measuring heads available in NTEGRA Spectra PNL extend performance

of the device. They facilitate investigations with techniques quite distinct from the

confocal measurements. For example, topography of the sample surface with atomic

resolution can be acquired. For details on measurements with SNOM and AFM measuring

heads, refer to PNL NTEGRA Solaris and PNL NTEGRA. Performing Measurements.

SNOM Measuring Head

The SNOM measuring head (Fig. 2-6) is used both for measurements of surface

topography of the sample and for measurements of its near-surface optical properties.

Detection of probe oscillation amplitude and phase is also available for those modes.

12

Chapter 2. Design

Fig. 2-6. SNOM measuring head

1 – output orifice for the optical fiber; 2 – leveling posts;

3 – probe holder; 4 – housing; 5 – mounting plate; 6 – motorized leveling post

All elements of the SNOM measurement head are assembled on the mounting plate 5 and

contained within the housing 4. The capacitance sensors are fixed to the bottom part of the

scanner. The end of the scanner has a special holder for the optical fiber probe 3. The top

part of the housing 4 has an output orifice 1 for the free end of the optical fiber.

There are three leveling posts to secure installation, horizontal leveling and approaching of

the probe to the sample. Two of them (pos. 2) are ordinary screws with fastening nuts. The

third post is a micrometer screw driven by a stepper motor 6 (motorized leveling post) that

provides the motorized translation of the probe towards the sample.

The probe is fixed in the holder 1 (Fig. 2-7) with spring clips 2, which also serve as

electrical contacts to acquire signal from the sensor. During installation of the sensor, the

optical fiber is pulled through the orifice 5. The scanner 3 provides scanning of the selected

XY area of the sample by the probe. It tracks the surface landscape. Observation of the

probe tip during the approach procedure or scan area selection is available through a

special groove in the protective case 4.

13

NTEGRA Spectra Probe NanoLaboratory. (Inverted Configuration with Renishaw Spectrometer).

Fig. 2-7. Probe holder assembly

1 – probe holder; 2 – spring clips; 3 – bottom of the scanner;

4 – protective case; 5 – optical fiber input orifice

operating distance and maintaining that distance during probe scanning of the sample.

Position of the probe in the XY plane during scanning is controlled with capacitance

sensors.

Technical specifications of the SNOM measuring head:

Scan range:

− in XY plane 100×100 m

− in Z direction 7 m

Resolution:

− shear Force method:

in XY plane < 100 nm

in Z direction < 1 nm

− optical method:

in XY plane ~ 100 nm

in Z direction –

Number of pixels up to 1024×1024

Probe-to-sample approach mode automated (motorized)

14

Chapter 2. Design

AFM measuring head

The AFM measuring head (Fig. 2-8) is used for qualitative and quantitative measurements

of near-surface characteristics of various objects and properties of physical fields of

associated with these objects.

Fig. 2-8. AFM measuring head

1 – laser adjusting screws; 2 – photodiode adjusting screws;

3 – probe holder; 4 – housing; 5 – mounting plate; 6 – leveling posts

The measuring head consists of the mounting plate 5 with other components assembled on

it. Capacitance sensors, which determine the position of the scanner, are fixed to the

bottom of the scanner. The end of the scanner has a special holder for the probe 3.

There are three leveling posts to secure installation, horizontal leveling and approaching of

the probe to the sample. Two of them (pos. 6) are ordinary screws with fastening nuts. The

third post is a micrometer screw driven by a stepper motor 6 (motorized leveling post) that

provides the motorized translation of the probe towards the sample.

The laser adjusting screws 1 are used to aim the laser beam at the probe. The beam

reflected from the probe is acquired by the photodiode. The adjusting screws 2 provide

aligning the photodiode against the beam.

15

NTEGRA Spectra Probe NanoLaboratory. (Inverted Configuration with Renishaw Spectrometer).

Fig. 2-9. Probe holder assembly

1 – probe; 2 – sapphire pedestal; 3 – spring clip; 4 – trapezium lever

Design of the probe holder is shown in Fig. 2-9. The probe 1 is set on the sapphire pedestal

2 and is fixed by the spring clip 3. The clip is loosened and tightened by the trapezium

lever 4. A piezo vibrator is located under the sapphire pedestal. Its function is to excite

oscillations of the cantilever at a given frequency during measurements on semi-contact

techniques.

Technical specifications of the AFM measuring head:

Scan range:

− in XY plane 100×100 m

− in Z direction 10 m

2.1.5. Additional Cables

For AFM spectrometry or for SNOM spectrometry, the X- and Y-scanners of the

exchangeable mount and the Z-scanner of the measuring head are connected to the main

controller while the X- and Y-scanners of the measuring head and the Z-scanner of the lens

are connected to the slave controller. This arrangement allows:

− moving the probe in XY plane for its precise alignment along the optical axis of the

lens;

− selecting the scan area and approaching the probe to the selected region of the sample

surface;

− confocal scanning for taking the surface topography (the configuration AFM-

Spectrometer).

16

Chapter 2. Design

This connection needs additional cables, a switching cable and a Z-splitter, which

distribute signals from the scanners of the measuring head, of the exchangeable mount, and

of the lens.

The Z-splitter separates signals from the slave controller to different scanners. Z-socket of

the splitter (pos. 2 on Fig. 2-10) transmits the Z signal that controls the lens scanner placed

in the exchangeable mount. XY socket (pos. 1) transmits X and Y signals that control the

XY-sections of the measuring head scanner.

Fig. 2-10. Z-splitter

1 – XY socket; 2 – Z socket; 3 – CONTROLLER2 socket

The switching cable (Fig. 2-11) supplies the measuring head scanner with the Z signal

from the main controller and the X and the Y signals from the slave controller instead of

the main one.

Fig. 2-11. Switching cable

1 – SCAN+SENSOR socket; 2 – XY socket

17

NTEGRA Spectra Probe NanoLaboratory. (Inverted Configuration with Renishaw Spectrometer).

2.2. Detectors

Andor CCD

Andor CCD is used in a wide range of measurements and has brilliant spectral and time

characteristics. It contains a built-in thermoelectrical cooling system (Peltier element),

which allows to cool the CCD-matrices down to –90 °С.

Renishaw CCD

Renishaw CCD camera is incorporated into the spectrometer. It is used in spectroscopy

measurements. For details on the CCD camera, refer to Renishaw user’s manual.

2.3. Controllers

The main and slave controllers are used to control the NTEGRA Spectra PNL

measurement system and to process signals from measuring heads, to convert signals from

the control software as well as to control the scanners, the probe holder piezo-drive, and

auxiliary devices.

The main controller controls the instrumentation during the scanning procedure while the

slave controller is used for approaching, for focusing the lens on the sample surface, and

for aligning the probe along the optical axis of the lens.

The controllers are labeled as follows:

− main controller – model BL222NNTF (BL222RNTF) or BL227NNTF (BL227RNTF);

− slave controller – model BL222SS.

The controllers interact with the system’s computers through interface cards installed

inside the computers.

For a detailed description of the SPM controllers, refer to Control Electronics.

18

Chapter 2. Design

19

2.4. Computer

The computer controls the PNL NTEGRA Spectra electronics. Besides, the control

software installed on the computer allows to process the measuring data. The computer is

connected to the main and slave controllers, to the spectrometer, and to the Andor CCD-

camera. The control system computer has the following characteristics:

− Processor: Pentium4, 2800 MHz;

− RAM: 1000 MB;

− Hard drive: 80 GB;

− DVD-RW drive.

 NOTE. Due to the dynamic development of the computer market, these computer

specifications can be altered without notice.

NTEGRA Spectra Probe NanoLaboratory. (Inverted Configuration with Renishaw Spectrometer).

3. Basic Safety Measures

General Safety Measures

− Ground the instrument before operation!

− Do not disassemble any part of the instrument. Disassembling of the product is

permitted only to persons certified by NT-MDT Co.

− Do not connect additional devices to the instrument without prior advice from

NT-MDT Co.

− The instrument contains precision electro-mechanical parts. Therefore, protect it from

mechanical shocks.

− Protect the instrument against the influence of extreme temperature and moisture.

− For transport, provide proper packaging of the instrument to avoid its damage.

Electronics

− To reduce possible influence of power line disturbances on the measurements, use of a

surge filter is recommended for electrical supply of the instrument units.

− Before operation, set the voltage selector of the SPM controller to the position

corresponding to local electrical power line (this is only done with the controller

being off!).

− Switch the instrument off before any operation on connecting/disconnecting its cable

connectors. Disconnecting or connecting the cable connectors during operations may

cause damage to the electronic circuit and disable the instrument. A warning label is

attached to the SPM controller of the instrument (Fig. 3-1).

Fig. 3-1

Laser

− Observe safety measures for operation with devices containing sources of laser

radiation. See warning labels on the laser sources and on AFM measuring heads

(Fig. 3-2).

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