With the development of the probe microscopy and nanoelectronics, it has emerged the need to develop standards for the beginning of the nanometer range, which couldn’t be made by means of the most advanced nanotechnologies (1-10 nm). The solution to this problem became possible only with creation of the standards of a fundamentally new type, not a static as it was in previous centuries, but dynamic (with a controlled displacement).
In the United States the Hector 100 device of magnetostrictive material controlled by the external magnetic field (prototype of dynamic gauge) has been manufactured. After calibration of this device at one point in nanometer range, it can be used to calibrate other measuring devices. To reduce the uncertainly of the calibration because of not guaranteed stability in time of magnetic characteristics, this device should be regularly calibrated using more precise and stable instruments. This solution has not received further development and application for the following reasons:
- thermal heating of the device that creates a magnetic field with subsequent thermal drift of such dynamic gauge;
- hysteresis and nonlinearity;
- lack of long-term stability of magnetic properties;
- sensitivity to external magnetic fields, which shielding is difficult, especially in the infra and low-frequency ranges;
- ability to pass the size only at one point of the nanometer range.
The experimental result confirming a possibility of the calibrated measurement of displacement at one point of the beginning of nanometer range was given in the publication [1]. It should be noted the necessity of calibration of the standard using more high-precision device for calibration of other measuring devices, or the existence of guarantees of stability of piezoelectric features throughout the interval between verifications.
The Advanced Technologies Center in Lomonosov Moscow State University has correctly solved the assigned task – the calibration at one point of nanometer range using one dynamic gauge. However, the cheapness and simplicity of production of the dynamic gauge on the basis of a piezoceramic plate does not provide metrological support of nanotechnology instrumentation, including of scanning probe microscopy. The existing functionality of this measurement gauge, which is patent-protected and approved for public free use, is only a sample of a new type of domestic dynamic nanometer standard, but cannot withstand the load of public usefulness.
How fair is it to offer to the public such standard of the nanometer for calibration of process equipment, to calm down and not try to improve the dynamic gauge, to talk about the availability of high-quality nanometer standard?
Under the present voltage, the piezoelectric ceramics provides movement of a gauge at one given value, but after removing the voltage it will not return to the starting point. If a different voltage is used, the calibration of gauge will be broken. Accordingly, calibration of the device or equipment requires a set of gauges of this type for different types of movement.
NANO-ATTO Metria has solved another problem – calibration using one dynamic gauge at all points of nano- and picometer ranges [2]. The following solutions are developed for minimization of a hysteresis and creep and for ensuring long-term stability in dynamic gauges:
- homogeneous monocrystalline material (like lithium niobate) is used instead of polycrystalline, which is typical for the piezoceramics;
- stability in time of dynamic gauges is provided (in contrast to the piezoceramics due to the lack of need for a polarization at production, and depolarization during storage and application);
- the specialized high-voltage analog-to-digital systems and appropriate software are developed for control.
Despite the difficulty of the problems in the areas of materials science, technology and devices using one dynamic gauge at all points of nano- and picometer ranges has for the first time become possible.
The metrological measuring set with the dynamic gauge developed by NANO-ATTO Metria is a technically complex and knowledge-intensive product, which is many times superior to metrological devices based on piezoceramics.
It is not enough to replace a type of material, that is to use the monocrystal instead of piezoceramics. It is necessary to achieve that the used crystals didn’t reproduce properties of piezoceramics. Knowledge in the field of crystallography, long calculations of experts, the complex technological chain of processing of the material have allowed to orient the crystal and to provide it with the necessary properties.
Since the amount of movement of the crystals is less than that of piezokeramics, it is necessary to generate a voltage of thousands of volts. Complicated electronic control system has small dimensions, but provides big capabilities and stable results. With the possibility of increase the output voltage up to 2 000 V, the generated electric signals have the controlled shape, which is set from the computer.
Optical interferometers with subnanometre measurement uncertainty, which long-term stability is provided by optoelectronic watching system on the basis of a cesium cell, have been developed for calibration of our dynamic gauges. This interferometer with stabilization of the radiation frequency using the cesium cell guarantees responsibility of measuring the displacement lengths and linear displacements of objects in the nanometer range.
Any scientific activity should be able to choose, recognize and offer the public the best available. The scientific responsibility to society determines that the work of scientists brings benefits, meets the needs of people, the conclusions specify the way for further development, become the basis for reliable forecasts and possible warnings. Scientific creativity, based on deep knowledge, should be continued by followers. Science must speak the truth, therefore, the offer as a metrological tool of the cheap, uncomfortable and irresponsible instrumentation for calibration is misleading the public. I, as a Professor of the Lomonosov Moscow State University, am not indifferent to results, which are achieved within its walls. I consider it necessary to inform the scientific community about the shortcomings of the approach of the authors of [1] to the problem of metrological support of nanotechnology.
We propose to conduct an independent test of the calibration standards at a public site selected by the scientific community.
So, today the development of the gauges is conducted in two ways:
- creation of static gauges on the basis of modern nanotechnology, which not outplace their development;
- creation of dynamic gauges, allowing to exceed in tens and hundreds of times the manufacturing precision of developed elements of nanometer size.
Dynamic gauges allow the realization of the essential requirement that is advanced development of metrology in comparison with the nanotechnology.
Engels wrote that knowledge becomes a driving force when it grabs the masses, so it is necessary to support in every possible way the various developments in the field of dynamic gauges, conducted by leading research teams. A few years ago we were alone in the field of creation of standards, but as soon as have presented a new development, publications and samples, we began to be opposed.
Current methods and standards do not allow careful calibration as there is no existing well-functioning equipment. There are no strict standards, only not very correct, and it seems that it suits everybody. Clever wording of officials who are responsible for the development of the nanoindustry do not reflect reality. The lack of interest from developers and enterprises of the domestic nanoindustry in the metrological measuring set with dynamic gauge and the lack of demand for the latter demonstrate an unwillingness to know the truth about the actual state of affairs or shortcomings.
With the development of dynamic gauges the level of development of nanometrology ceases to depend on the level of development of nanotechnology and many times exceeds it. In the first stage, nanotechnology was developed by improving the existing solutions. However, the fatal shortcomings as the lack of locality in the molecular beam epitaxy or destruction of the surface layer by high-energy ions in lithography have hindered the development of nanotechnology, based on the traditional technologies, which were developed more than half a century ago. It became clear that further progress requires new solutions.
Attempts to develop new technology on the base of commercial tunneling and atomic force microscopes have been ineffective. New technologies require the equipment of new types, but not combinations of systems that are almost half a century old.
The implementation of the new developments requires followings:
- a choice of the new direction (for example, probe nanotechnologies);
- development team for the equipment;
- development team for technological processes;
- orientation to the socially demanded products, such as nanoelectronic circuits, nanosensors, micro- and nanomechanical devices, etc., numerously described in the scientific and technical literature;
- metrologists;
- a certain level of funding, as lack of it doomed to work only in the field of microscopy.
The lack of special nanotechnology equipment and of real nanotechnology leads to a lack of production and nanoindustry, respectively (at any level of development of nanometrology). An example of overcoming this problem is the creation in the USA of special companies for development of new equipment and processes (Zyvex in Silicon valley, Massachusetts Institute of Technology, National Institute of Standards and Technology (NIST), Thomas J. Watson Research Center, headquarters of IBM’s Research division). Similar organizations are also established in EU, Japan and South Korea. Result of their operation are such experimental results, as a controlled movements of atoms, single-electron and single-atom transistors, etc. In the USA, in addition to the effective National Nanotechnology Initiative, a long-term programme for atomically precise manufacturing has been developed.
A quarter of a century ago, in 1993, at the 2nd International conference on nanotechnology in Moscow the major projects in the fields of nanotechnologies, including probe nanotechnologies have been offered. But over the next years and until now in the country the projects not related to critical areas (for example, coatings for tools, etc.) are carried out. Work on scanning probe nanotechnology will make absolutely clear the applicability of all existing standards in different areas.
It is known that electronics is the most effective area for investment. The basic element of electronics is the transistor, therefore financing of projects on creation of nanotransistors with record parameters is the most reasonable because automatically activates the application of nanotechnology. Start of production of nanotransistors as nanoproducts will allow to eliminate existing backwardness and to develop the nanoindustry. With the advent of nanoproducts the nanometrology will be in demand, high-tech jobs will be created, the economy will actively develop.
Funding of nanotechnology in Russia is comparable to the amount of funding in the EU, which is more than enough for organization of works in the most cost-effective and technically perfect area. A question for RUSNANO: who in Russia is engaged in designing and manufacturing of transistors with nanometer resolution? Whether to put such tasks before the government of RUSNANO? Does the state set such task for RUSNANO? After receiving a positive answer to this question, we can speak about Russian nanoindustry, and at present it is just a beautiful illusion with spending of budget money, which is reflected on the glossy pages of publications.
The article's published in the magazine Nanoindustry, 2016, №6 (68). P. 60 - 67.
