rus
Issue #6/2017
L.Kolesnik, K.Moiseev, Yu.Panfilov, V.Ryabov, S.Sidorova
Laboratory equipment with remote access for thin film deposition in vacuum
Laboratory equipment with remote access for thin film deposition in vacuum
Thin film vacuum deposition systems with automatic control that is built-in into the system of remote access are considered. Methods for thermal, magnetron, ion beam and chemical vapor deposition of nanostructured thin films are used in equipment. The methodical support for the preparation of laboratory works and the virtual simulator for the training on the equipment are developed.
Теги: nanostructured coating thin-film technology vacuum deposition вакуумное осаждение наноструктурированныое покрытие тонкопленочная технология
Qualitative training of students of technical specialties, including nanoengineering, is impossible without laboratory practical work using modern equipment. The problem lies in the limited access of students to complex and, as a rule, expensive process or analytical equipment. Therefore, in most cases, the laboratory practice includes the study of technical documentation for equipment and methods of performing laboratory work, and the practical part is reduced to observation the work of the teacher and recording instrument readings. At such organization of lab work students do not receive practical skill of work on the equipment.
A laboratory complex for vacuum deposition of thin films with a remote access function, designed to give each student practical skills of working on vacuum process equipment, is developed in the BMSTU at the department of Electronic Technologies in Mechanical Engineering. Within the framework of two state contracts, the following solutions have been created: vacuum systems for the thin films deposition with an automatic control system; methodical support for studying the theoretical foundations of thin film technology and preparation for laboratory work; remote access system; virtual simulator that acts as a tool for training work on equipment [1].
The possibility of remote access allows students to study the theory, get acquainted with the device and the principle of its operation, master the methodology of performing laboratory work in a computer class, at home, in transport, etc., which saves time for both the student and the teacher.
COMPACT VACUUM
PROCESS EQUIPMENT
The УВН-1M vacuum unit, a part of the complex (Fig.1a), is equipped with an oil-free pumping system [2], a vacuum chamber with a volume of 2 liters, quick-detachable flanges, one of which is base for a film deposition source (resistive evaporator or magnetron), and another – for a substrate holder with a dielectric substrate on which contact pads are formed [3, 4]. A picoammeter, a LCR station or another device measuring the characteristics of a thin film is connected to the contact pads via a sealed current lead [4].
The second vacuum unit, МВТУ-11-1 [4] (Fig.1b), is equipped with an oil-free pumping system and technological sources that implement particle-beam methods for generating fluxes of film-forming particles: an electron-beam evaporator and an autonomous ion source. In the future it is planned to equip the unit with a pulse laser ablation system.
For both units, an automatic control system has been developed, connected to the local network and having the ability to access the Internet.
The configuration of the units allows to measure the key characteristics of the films directly during their deposition. As an example, Fig.2 shows a graph of the change in the current flowing between contact pads as a function of the formation time first of an islet film and then of a continuous film [4]. The nonlinear nature of current growth in the second section of the graph indicates an island growth of a thin film with coalescence of islands and change in the distance between them. This section allow to study the initial stages of growth of thin films depending on the deposited material, the deposition rate and the energy of the film-forming particles, which depends on the thin film deposition method.
The laboratory session includes the study of the theoretical foundations of thin film technology and of the methods of performing laboratory work with which the student can get acquainted by connecting to the Internet through an intuitive interface (Fig.3).
Training in equipment management is carried out using a virtual simulator built into the remote access system. Having passed the test and got the admission to the practical work, students, being in the computer class, begin to perform laboratory work in the remote access mode.
REMOTE ACCESS SYSTEM
AND VIRTUAL SIMULATOR
To provide remote access to the equipment, a special software was developed – the remote access server [5]. The automatic control system of the vacuum unit is connected to the remote access system via the pairing driver, which is an intermediate link between the equipment and the remote access server. The implementation of interaction with a real automatic control system is hidden inside the driver. Using a driver that conforms to the specification of a remote access system, it is possible to connect virtually any process equipment with a control system without changing the functionality of the software of the system.
The virtual simulator (Fig.4) allows to simulate the work, creating a feeling that the user controls the real equipment. This solution does not require the presence of an operator, allows to simultaneously conduct several virtual experiments and can be used for educational purposes and for scientific research. When working with equipment both in real-time remote access mode and in virtual simulator mode, common methods and algorithms are implemented except for operations requiring manual actions on the equipment side, for example, the loading of a substrate.
In the real-time remote access mode, the user controls the unit through a local computer network or the Internet, that is, works with the simulator.
LABORATORY UNIT FROM STANDARDIZED COMPONENTS
Having a sufficiently large choice of standardized components of vacuum equipment – small vacuum chambers, vacuum pumps, vacuum gauges, vacuum fittings, as well as thermal evaporation and ion sputtering sources – it is possible to assembly an inexpensive laboratory unit (Fig.5), to equip it with an automatic control system and to operate in the remote access mode. At the same time, it is possible to conduct laboratory work on courses of technological and research training cycles, as well as on the design and operation of vacuum process equipment, where students will acquire the skills of assembly from unified units, setting-up, starting the system and outputting it to specified operating modes.
CONCLUSION
The developed approach to conducting laboratory works can be applied to practically all methods of vacuum thin film deposition, including molecular beam epitaxy, atomic layer deposition and other methods. It can be implemented on any laboratory vacuum system for the deposition of thin films, which has an automatic control system, as well as on industrial equipment, for example, manufactured by the Research Institute of Precision Machine Manufacturing (Zelenograd) [6]. The series of small vacuum systems developed by the NIITM is quite suitable for implementing a remote access system and conducting training sessions and scientific research if they are equipped with methodological support and a virtual simulator, which can significantly expand the range of potential users of such equipment. ■
A laboratory complex for vacuum deposition of thin films with a remote access function, designed to give each student practical skills of working on vacuum process equipment, is developed in the BMSTU at the department of Electronic Technologies in Mechanical Engineering. Within the framework of two state contracts, the following solutions have been created: vacuum systems for the thin films deposition with an automatic control system; methodical support for studying the theoretical foundations of thin film technology and preparation for laboratory work; remote access system; virtual simulator that acts as a tool for training work on equipment [1].
The possibility of remote access allows students to study the theory, get acquainted with the device and the principle of its operation, master the methodology of performing laboratory work in a computer class, at home, in transport, etc., which saves time for both the student and the teacher.
COMPACT VACUUM
PROCESS EQUIPMENT
The УВН-1M vacuum unit, a part of the complex (Fig.1a), is equipped with an oil-free pumping system [2], a vacuum chamber with a volume of 2 liters, quick-detachable flanges, one of which is base for a film deposition source (resistive evaporator or magnetron), and another – for a substrate holder with a dielectric substrate on which contact pads are formed [3, 4]. A picoammeter, a LCR station or another device measuring the characteristics of a thin film is connected to the contact pads via a sealed current lead [4].
The second vacuum unit, МВТУ-11-1 [4] (Fig.1b), is equipped with an oil-free pumping system and technological sources that implement particle-beam methods for generating fluxes of film-forming particles: an electron-beam evaporator and an autonomous ion source. In the future it is planned to equip the unit with a pulse laser ablation system.
For both units, an automatic control system has been developed, connected to the local network and having the ability to access the Internet.
The configuration of the units allows to measure the key characteristics of the films directly during their deposition. As an example, Fig.2 shows a graph of the change in the current flowing between contact pads as a function of the formation time first of an islet film and then of a continuous film [4]. The nonlinear nature of current growth in the second section of the graph indicates an island growth of a thin film with coalescence of islands and change in the distance between them. This section allow to study the initial stages of growth of thin films depending on the deposited material, the deposition rate and the energy of the film-forming particles, which depends on the thin film deposition method.
The laboratory session includes the study of the theoretical foundations of thin film technology and of the methods of performing laboratory work with which the student can get acquainted by connecting to the Internet through an intuitive interface (Fig.3).
Training in equipment management is carried out using a virtual simulator built into the remote access system. Having passed the test and got the admission to the practical work, students, being in the computer class, begin to perform laboratory work in the remote access mode.
REMOTE ACCESS SYSTEM
AND VIRTUAL SIMULATOR
To provide remote access to the equipment, a special software was developed – the remote access server [5]. The automatic control system of the vacuum unit is connected to the remote access system via the pairing driver, which is an intermediate link between the equipment and the remote access server. The implementation of interaction with a real automatic control system is hidden inside the driver. Using a driver that conforms to the specification of a remote access system, it is possible to connect virtually any process equipment with a control system without changing the functionality of the software of the system.
The virtual simulator (Fig.4) allows to simulate the work, creating a feeling that the user controls the real equipment. This solution does not require the presence of an operator, allows to simultaneously conduct several virtual experiments and can be used for educational purposes and for scientific research. When working with equipment both in real-time remote access mode and in virtual simulator mode, common methods and algorithms are implemented except for operations requiring manual actions on the equipment side, for example, the loading of a substrate.
In the real-time remote access mode, the user controls the unit through a local computer network or the Internet, that is, works with the simulator.
LABORATORY UNIT FROM STANDARDIZED COMPONENTS
Having a sufficiently large choice of standardized components of vacuum equipment – small vacuum chambers, vacuum pumps, vacuum gauges, vacuum fittings, as well as thermal evaporation and ion sputtering sources – it is possible to assembly an inexpensive laboratory unit (Fig.5), to equip it with an automatic control system and to operate in the remote access mode. At the same time, it is possible to conduct laboratory work on courses of technological and research training cycles, as well as on the design and operation of vacuum process equipment, where students will acquire the skills of assembly from unified units, setting-up, starting the system and outputting it to specified operating modes.
CONCLUSION
The developed approach to conducting laboratory works can be applied to practically all methods of vacuum thin film deposition, including molecular beam epitaxy, atomic layer deposition and other methods. It can be implemented on any laboratory vacuum system for the deposition of thin films, which has an automatic control system, as well as on industrial equipment, for example, manufactured by the Research Institute of Precision Machine Manufacturing (Zelenograd) [6]. The series of small vacuum systems developed by the NIITM is quite suitable for implementing a remote access system and conducting training sessions and scientific research if they are equipped with methodological support and a virtual simulator, which can significantly expand the range of potential users of such equipment. ■
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