PART 1. Basic Information. Contents

PART 1. Basic Information

Contents

1 DESIGN..................................................................................................................................................1-2 1.1 APPROACH AND SCANNING UNIT...................................................................................................1-3 1.2 EXCHANGEABLE SAMPLE HOLDERS ..............................................................................................1-6 1.3 EXCHANGEABLE SCANNERS ..........................................................................................................1-7 1.4 MEASURING HEADS.......................................................................................................................1-8

1.4.1 Universal Measuring Head.............................................................................................1-8 1.4.2 Scanning Measuring Head ...........................................................................................1-11 1.4.3 STM Head.....................................................................................................................1-14

1.5 PROTECTIVE HOOD......................................................................................................................1-15 1.6 CONTROL SYSTEM .......................................................................................................................1-15

2 BASIC SAFETY MEASURES ...........................................................................................................1-16

3 OPERATING CONDITIONS ............................................................................................................1-18

4 TRANSPORT AND STORAGE INSTRUCTIONS .........................................................................1-19

1-1

PART 1. Basic Information

1 Design

The basic functional units of the instrument are:

- measuring unit:

- approach and scanning unit;

- measuring head;

- scanner.

- control system:

- SPM controller;

- computer with interface board.

- vibration isolation system;

- closed-loop scanner equivalent (CLE);

- optical viewing system;

- protective hood.

The general view of Solver PRO instrument is shown on Fig. 1-1.

Fig. 1-1 Solver PRO general view 1 - approach and scanning unit, 2 –measuring head, 3 –CLE,

4 - Vibration Isolation System, 5 – Optical Viewing System

1-2

1. Design

Modularity principle is realized in scanning probe microscope Solver PRO. Such approach allows to configure the device to perform measurements of characteristics of the widest variety of objects – from atomic structure nanotubes to the quality of lacquer coating. The breadth of application is provided not with creation of an expensive and cumbersome measuring combine but with the opportunity of user selection of an instrument configuration, which would suit most to his/her range of tasks.

Actually, Solver PRO represents the approach unit and SPM controller with a wide set of mechanical, electromechanical and electronic modules, blocks and units, on the basis of which an SPM can be built simply enough, which would be configured to solve a specific task.

Such instrument design provides its universality and allows to operate practically in all known modes of the probe microscopy.

1.1 Approach and Scanning Unit

Approach and scanning unit (further – the approach unit) is the base device of the instrument. The basic functional purpose of the unit is landing and positioning of a sample.

Measuring heads, exchangeable scanners, sample holders, heating stage, liquid cells, etc. are installed on the approach unit.

Fig. 1-2 presents the general view and basic elements of the approach unit.

Fig. 1-2. Approach and scanning unit 1 – base, 2 – platen, 3 – legs, 4 – universal stage, 5 – manual approach screw,

6 – positioning device, 7 – sample holder, 8 – joining pipe

1-3

PART 1. Basic Information

The approach unit is installed on a massive base 1 on three legs 3. The whole approach unit is based on a platen 2. From below the platen, under a casing, there is a sample-to-probe landing mechanism. Universal stage 4, positioning device 6 and mates are located on the top. Besides, there is a joining pipe 8 located on the platen, which is used at work with a protective cover for gas charging or air exhaust.

Principle of operation of the approach unit

The approach unit design is schematically shown on Fig. 1-3.

Fig. 1-3. Approach unit design 1 – stepper motor, 2 – feed screw, 3 – nut, 4 – traveling cylinder,

5 – static barrel, 6 – positioning device, 7 – sample, 8 – manual approach screw, 9 – stopper, 10 – platen

Step motor 1 rotates feed screw 2. Nut 3 moves along the feed screw and drives traveling cylinder 4; positioning device 6 is fixed on traveling cylinder 4. Traveling cylinder sits in static barrel 5, which is fixed on platen 10. Stopper 9 prevents nut 3 from rotating. Manual approach screw 8 is intended for rough landing of a sample to the probe.

During automatic landing as soon as the sample starts interacting with the probe and the feedback signal reaches a preset value ("Set Point"), the stepper motor automatically makes few steps in reverse. The nut leaves contact with the top wall of the traveling cylinder. The motor stops, and the traveling cylinder remains in place due to friction. The reverse travel is set by the software in a settings file. Thus, mechanical contact between the approach drive and the scanner is eliminated during measurements.

1-4

1. Design

Universal stage and positioning device

The universal stage is fixed on the approach unit platen, and the positioning device is installed on the traveling cylinder of the approach unit.

Fig. 1-4. Universal stage and positioning device

1, 2 – seats for installation of measuring heads; 3 – legs for installation of a mirror;

4 – positioning device

Fig. 1-5. Positioning device 1 – micrometric screws, 2 – spring supports

The universal stage has seats for installation of measuring heads (see pos. 1, 2 on Fig. 1-4) and legs (see pos. 3 on Fig. 1-4) for installation of an auxiliary mirror at work with the Optical Viewing System.

Sample holder, scanner or another device, on which the sample is fixed, are installed into the positioning device. Positioning along XY axes is performed using micrometric screws 1 (Fig. 1-5). Spring supports 2 are located opposite to micrometric screws, fixing the device with a sample on the positioning device, pressing it to micrometric screws. The range of positioning along XY axes makes 5x5 mm. Positioning accuracy – 5 μm.

1-5

PART 1. Basic Information

Connectors

Arrangement of electric connectors on the body of the approach unit is shown on Fig. 1-6.

Fig. 1-6. Arrangement of electric connectors 1 – connector for exchangeable scanner, 2 – connector for heating stage,

3 – grounding jack, 4 – socket for bias voltage supply to the sample

1.2 Exchangeable Sample Holders

The sample holder is installed on the positioning device.

General view of the sample holder is presented on Fig. 1-7. The sample holder consists of sample stage 2 and base 1 located on the carriage.

Fig. 1-7. Sample holder 1 – base; 2 – sample stage, 3 – carriage; 4 – grounding jack

1-6

1. Design

The substrate with a sample is installed on the sample stage. Clips (see pos. 1 on Fig. 1-8) press the substrate to three support balls (see pos. 2 on Fig. 1-8) of the sample stage.

Fig. 1-8. Sample stage 1 – clip; 2 – support ball

ATTANTION! Do not install substrates of more than 0,5 mm height on the sample stage since it may result in loosening or breakage of the clips.

There is a grounding jack (see pos. 4 on Fig. 1-7) for grounding of samples on the holder. Grounding is achieved through the grounding wire (Fig. 1-9).

Fig. 1-9. Sample holder grounding wire

1.3 Exchangeable Scanners

Exchangeable scanner is installed on the positioning device and is connected to a socket on the approach unit body (see pos. 1 on Fig. 1-6).

General view of the exchangeable scanner and its design are shown on Fig. 1-10. The basis of the exchangeable scanner is a piezo-ceramic tube, covered with metal sheath. A carriage is fastened to the sheath, and the sample stage is installed on the piezotube.

Z

X Y1

2

3

Fig. 1-10. Scanner design 1 – protective cover of scanner tube, 2 – carriage, 3 – sample stage

1-7

PART 1. Basic Information

ATTENTION! Do not apply to the scanner forces bigger than it is necessary for installation of a substrate with a sample. Avoid impacts on the scanner and its lateral displacement. Remember that thickness of the scanner walls makes only 0,5 mm. Do not install samples of more than 100 g weight on the scanner.

Exchangeable scanners used in Solver PRO instrument have the following specifications:

Model Scan range Minimal scan step

SC103 3x3x1.3 μm (±10%) 0.0004 nm

SC110 10x10x2 μm (±10%) 0.0011 nm

SC150 50x50x3 μm (±10%). 0.006 nm

The scanner hysteresis is compensated by software and hardware (when using CLE).

1.4 Measuring Heads

1.4.1 Universal Measuring Head

Measuring heads allow to realize "Scanning by Sample" configuration. They are represented by a universal measuring head and a number of specialized measuring heads. This section describes the universal measuring head for measurements in AFM mode. The specialized models will be described in sections devoted to corresponding modes and measurement techniques.

The universal measuring head allows to realize practically all AFM modes both in the air environment and in a liquid. Wide range of measurements techniques is realized due to utilization of a set adjustment units, which are specialized for certain measurements techniques and parameters.

General view of the universal measuring head is presented on Fig. 1-11.

Fig. 1-11. Universal measuring head

1-8

1. Design

Measuring head design

Fig. 1-12 shows the basic components of the universal measuring head.

a) b)

Fig. 1-12. Measuring head design 1,2 – X, Y movement screws of the adjustment unit;

3, 4 – photodiode positioning screws; 5 – pressing handle; 6 – laser; 7 – four-section photodiode; 8 – adjustment unit connector;

9 – polycrystalline sapphire bearing stage; 10 – body, 11 – adjustment unit, 12 – base

The measuring head contains optical system of cantilever deflection detection (including the laser and the four-section photodiode) and the adjustment unit.

The measuring head design is schematically presented on Fig. 1-13.

Fig. 1-13. Measuring head design

Stage XY movement screws (see pos. 1, 2 on Fig. 1-12) serve for pointing the laser beam on the cantilever. With their help the cantilever is installed in a position when the laser beam hits its tip. Using the photodiode positioning screws (see pos. 3, 4 on Fig. 1-12) the four-section photodiode is moved so that the laser beam that is reflected from cantilever hits precisely the center of the photodiode.

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PART 1. Basic Information

Adjustment unit (Fig. 1-14) is installed on the round base of the measuring head (see pos. 12 on Fig. 1-12) and is fixed with the pressing handle 5 to the movement screws 1, 2. Adjustment unit is connected to a reciprocal socket on the measuring head body. The probe holder is located on the stage (see pos. 1 on Fig. 1-14), the probe is fixed in the probe holder.

Fig. 1-14. Adjustment unit 1 – probe holder, 2 – measuring head connector

The probe holder design is shown on Fig. 1-15. The probe is installed on the polycrystalline sapphire stage 2 and is fixed with the clamping spring 3. The spring is lifted and lowered by means of the trapezoid lever 4. Piezodriver is located under the polycrystalline sapphire stage, which forces the cantilever to fluctuate with the set frequency in contactless and semicontact measurement modes.

Fig. 1-15. Probe holder with the probe installed 1 – probe, 2 – polycrystalline sapphire stage, 3 – clamping spring, 4 – lever

ATTENTION! When replacing the probe use only the trapezoid lever to release the clamping spring. Use of other improvised means will result in loosening of the clip, which will lead to poor-quality work of the instrument

1-10

1. Design

Probe for AFM measurements

The probe has the form of an elastic girder called “cantilever” (see position 2 in Fig. 1-16), which is fixed to the silicon base, called chip, of the probe. The probe tip, which is in the form of a sharp pin, is located on the free end of the cantilever.

Probes with cantilevers of the following two types are generally used for AFM:

- In the form of a rectangular girder (Fig. 1-16 a);

- Triangular cantilevers formed by two beams (Fig. 1-16 b).

a) with rectangular cantilever b) with triangular cantilever

Fig. 1-16. Overall view of the probe for AFM measurements 1 – chip; 2 – cantilever; 3 – probe tip

A probe can have several cantilevers of various lengths (and consequently, of different elasticity).

1.4.2 Scanning Measuring Head

Scanning measuring heads allow to realize "Scanning by Probe" and "DualScan" configuration (in combination with the scanner installed on the positioning device of the approach unit).

The scanning measuring head can work without the approach unit as a separate microscope. In this case the sample is fixed on the sample stage and the head is installed above or directly on the sample, which allows to investigate samples of unlimited sizes.

Scanning measuring heads are represented by models for AFM mode measurements in standard conditions, and also with a number of specialized models.

This section describes the scanning measuring head for AFM mode measurements. Specialized models will be described in sections devoted to corresponding measurement modes and techniques.

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PART 1. Basic Information

Scanning measuring head design

The general view of the scanning measuring head is presented on Fig. 1-17.

Fig. 1-17. Basic elements of the scanning measuring head 1 – base; 2 – scanner tip; 3 – probe holder; 4 – laser adjusts;

5 – photodiode adjusts; 6, 7 – legs; 8 – supports

In order to point the laser beam on the cantilever, the laser adjusts are used (see pos. 4 on Fig. 1-17) to find such position, at which the laser beam will hit the cantilever tip.

For installation and horizontal alignment the measuring head is supplied with height-adjustable screw legs (see pos. 6 on Fig. 1-17). Two front legs with counternuts provide height installation of the measuring head above a sample. The 7 support is used to approach the tip to a sample. The scanning measuring head is supplied with supports (see pos. 8), on which it is installed in the inverted position, for example, to replace the tip.

The scanning measuring head design is schematically shown on Fig. 1-18. The scanning measuring head is comprised with the scanner, the probe holder and also the optical system of for cantilever tracking, consisting of the laser, the four-section photo diode and two mirrors.

Fig. 1-18. Scanning measuring head design

1-12

1. Design

The scanner is fixed inside the body of the head. The metal tip connected to the scanner is protracted outside the body of the head. The probe holder is installed on a tip.

The construction of the probe holder is shown on Fig. 1-19. The probe is installed on a aluminum stepped seat 2 and is fixed with clamping spring 3. The spring rises and falls by means of trapeziform lever 4. The piezodriver is located under the aluminum stepped seat; it imposes oscillations to the cantilever with the set frequency when using contactless and semi-contact measurement modes.

Fig. 1-19. Probe holder with the probe installed 1 – scanner tip, 2 – aluminum seat, 3 – clamping spring, 4 – lever, 5 – probe

ATTENTION! When installing the probe, remember that the probe holder is installed on the scanner tip. Do not apply to the holder forces bigger than necessary for probe installation. Avoid impacting the scanner tip and its lateral displacement. Remember that the scanner walls thickness makes only 0.5 mm.

For convenience of laser beam pointing on the cantilever, there is a special viewing opening in the scanner tip (see pos. 3 on Fig. 1-20), through which, by means of a viewing mirror, it is possible to see the cantilever. The scan area could be observed using the viewing mirror.

Fig. 1-20. 1 – Scanner tip, 2 – Probe holder, 3 – Viewing opening

1-13

PART 1. Basic Information

Scanner tip

Viewing mirror

Probe holder

Probe Viewing area

Sample

Viewing opening

Viewing angle 30°

Fig. 1-21. Scanner tip design

1.4.3 STM Head

An overall view of the STM head is shown in Fig. 1-22.

a) front view b) view from the bottom

Fig. 1-22. STM head 1 – probe holder; 2 – support points for mounting on the exchangeable mount

The sharpened part of a PtIr, PtRo or W wire of 8 - 10 mm length and of 0.25 - 0.5 mm diameter is used as an STM probe.

The probe is installed in the V-shape grooves and is fastened with the spring clip (Fig. 1-23).

Fig. 1-23. Probe holder

1-14

1. Design

1.5 Protective Hood

The protective hood is installed on a platen of the approach unit.

The protective hood is intended for protection against electromagnetic fields, acoustic noise, temperature drops. Besides that, the protective hood creates volume for boost gas charging or air exhaust.

There is a special wire on the approach unit for grounding of the protective hood, which is connected to the grounding jack on the cap (Fig. 1-24).

Fig. 1-24. Protective hood is installed on the approach unit 1 – grounding jack

1.6 Control System

Solver PRO control system includes the following:

- SPM Controller;

- CLE controller;

- Computer with interface board.

The manual of controllers see in «Control Electronics».

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PART 1. Basic Information

2 Basic Safety Measures

ATTENTION! Read carefully this section, before starting the instrument operation.

Electronics

- Ground the instrument before operation.

- Before operation, set the power switch of the SPM controller to the position corresponding to value of the local electrical power line (this is only done with the controller being off!).

- Switch the instrument off before 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. 2-1).

Fig. 2-1

Laser

- 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. 2-2), laser sources.

Fig. 2-2

1-16

2. Basic Safety Measures

Scanner

- Do not apply to the scanner forces bigger than it is necessary for installation of a probe or a substrate with a sample. Avoid impacts on the scanner and its lateral displacement. Remember that thickness of the scanner walls makes only 0.5 mm.

General Safety Measures

- Do not disassemble any part of the device. Disassembling of the product is permitted only to persons certified by NT-MDT.

- Do not connect additional devices to the instrument without prior advice from an authorized person from NT-MDT.

- This 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 for the instrument so as to avoid its damage.

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PART 1. Basic Information

3 Operating Conditions

To provide for the normal operation of the device, it is recommended to observe the following conditions:

- environment temperature: 20 ±5˚C;

- temperature drift less than 1˚C per hour;

- relative humidity less than 80%;

- atmospheric pressure 760 ±30 mm Hg;

- vibration requirement vibration criterion VC-C, 12.5 µm/s (one-third octave band criterion);

- electric mains with 110/220 V (+10%/-15%), 50/60 Hz and grounding;

- the room should be protected from mechanical vibrations and acoustic noises, either internal or external;

- the device should be protected from the direct sun radiation impact;

- the measuring unit of the instrument (the approach unit with the measuring head) should be placed on a separate table away from computers and monitors, to eliminate electromagnetic interference;

- the table intended for installation of the measuring unit of the instrument must be stable and, whenever possible, massive.

The operation of the device is susceptible to heat flows, draughts and sudden alternations in temperature and humidity.

1-18

4. Transport and Storage Instructions

4 Transport and Storage Instructions

Storage Instructions

The instruments should be stored packaged in clean and dry premises with low ambient temperature variations:

- Acceptable temperature inside the premises is plus (20 ± 10) °C;

- Acceptable humidity inside the premises is < 65 %.

Transport Instructions

- The instrument should be carefully packaged to avoid damage during transport.

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