Fianite in Optoelectronics
Advanced “Semiconductor-Dielectric” Fianite-Based Structures for Optoelectronic Devices of New Generation
Tech Area / Field
- MAT-SYN/Materials Synthesis and Processing/Materials
- INF-ELE/Microelectronics and Optoelectronics/Information and Communications
- MAN-MAT/Engineering Materials/Manufacturing Technology
8 Project completed
Senior Project Manager
Tyurin I A
Institute of General Physics named after A.M. Prokhorov RAS, Russia, Moscow
- NPO Orion, Russia, Moscow\nNIIIT (Pulse Techniques), Russia, Moscow
- Université du Maine, France, Le Mans\nInnovations for High Performance Microelectronics, Germany, Frankfurt/Oder\nInstitute for Energy Technology (IFE), Norway, Kjeller
Project summaryThe Purpose of the Project is to develop a wide spectrum of the high-tech FIANITE-based heteroepitaxial structures for optoelectronic devices of new generation. It is suggested multifunctional application of FIANITE as substrates for “semiconductor-on-dielectric” structures, buffer layer of heteroepitaxial structures, gate dielectric, as well as protective layer isolating surface of functional structures from corrosive environment. To reach this goal a set of unique technologies will be developed, namely: synthesis of large FIANITE crystals of high structure perfection, synthesis of films of AIIIBV compounds on FIANITE, as well as FIANITE films on Si, Ge and GaAs. In turn, on this basis original technologies for single and multi-layer “semiconductor-FIANITE” structures will be developed. Advantages of these novel materials and technologies will be confirmed by development and manufacturing of pilot samples of the optoelectronic devices of new generation, those which will be superior to the analogs currently in use.
The Project is urgent due to a high demand of the modern industry in new materials and technologies for electronics and optoelectronics. Currently, optoelectronics penetrated into almost all fields of human activity: science, industry, medicine and housekeeping. Detectors and generators of optic radiation are very important components of computers, information processing technique, fiber-optic communication, Internet and various laser optoelectronic systems. Worldwide annual array production for analog and digital video- and photo-devices has exceeded 150 millions units. Hundreds millions of photodetectors are in requiring for distant monitoring systems. Development of the IR- sensor arrays is drastically fast. The array-based thermo-visualization devices and detectors are widely used in extreme situations, in particular, including terrorism combat, as well as in monitoring of power plants and in ecological studies.
Evaluation of characteristics of “semiconductor-on-dielectric” photosensitive structures, which are currently in use, as well as reviewing scientific publications in this field, provides evidence that the most part of conventional dielectric materials (i.e. sapphire) actually exhausted its resources. For instance, microelectronics based on Si/SiO2/Si structures approached to its physical limit. Further progress in the development of the main fields of modern electronics seems to be associated with a search for alternative materials and technologies.
FIANITE - single crystals of cubic zirconia or hafnia –based solid solutions can be one of the promising materials for modern electronics and optoelectronics. Industrial technology of the crystals was first in the world developed by the authors of the Project in 60-70s. The studies have been carried out in P.N. Lebedev Physical Institute of the USSR Academy of Science (Russian abbreviation: FIAN) that was the reason for the name of the crystals. As a substrate material for silicon epitaxy FIANITE single crystals were at first used in France and USA about 20 years ago. Later on, the studies carried out by French and American scientists and then by scientists in the other countries, including those performed by the authors of the Project, have shown other promising applications of FIANITE in opto- and microelectronics thus demonstrating its multifunctional properties.
In comparison with the other dielectrics, FIANITE being used as a substrate material and buffer layer for Si and AIIIBV compounds epitaxy possesses a number of advantages:
- Cubic structure (in contrast to hexagonal one of sapphire), it is possible to alter fianite cubic lattice constant by varying ratio of the main and stabilizing oxides that allows an optimum matching between substrate and cubic lattice of semiconductor films thus improving its structural perfection;
- Good insulating properties: resistivity 1012Ohm•cm at 300K;
- Negligible value of diffusion coefficients of cations up to 1000…1200oC that prevents interdiffusion of impurities between substrate and film and undesirable doping, which can damage heteroepitaxial layers through penetration of impurity atoms;
- Broad spectral range of transmission (260…7500 nm) completely covers actual absorbance and emission of Si, AIIIBV compounds and its solid solutions. That makes “semiconductor-on-FIANITE” structures very promising for the development of various optoelectronic devises with improved operational parameters (avalanche photodiodes, light-emitting and laser diodes, etc).
FIANITE is also a good gate dielectric due to its high dielectric constant value (25…29.7). Thin layer of FIANITE is a barrier for diffusion of impurities, thus providing significant reducing of the loss of current (up to 1000-fold and even more) in high-integrated devices. Thin films of FIANITE and the related solid solutions, i.e. Zr(Ce)O2, can be used as insulating layers (alternative to SiO2, SiC, Si3N4) for development of “semiconductor-dielectric” multilayer structures, those which are basic for optoelectronics. Due to high chemical inertness the FIANITE films can be used as protective layers.
Therefore, due to this unique combination of physicochemical properties, FIANITE is very promising multifunctional material for novel micro- and optoelectronic technologies. The material application can result in a considerable progress in this field. However, considering the data published, the studies carried out in these promising directions so far are of preliminary search character and were not completed up to device applications. In last five years the countries taking leading positions in microelectronics and high-technologies have shown drastic rise of interest to various aspects of the application of FIANITE in micro-, opto- and UHF- electronics.
Currently, the world FIANITE single crystal production is estimated at ~100…200 tons per year. To main extent the crystals are produced for jewelry. However, such crystals do not meet rigorous requirements of electronics regarding its chemical composition, size, structural perfection and physicochemical parameters. The authors of the Project hold leading position in the field of growth and investigation of new zirconia- and hafnia-based crystal materials for modern electronic technologies. In preliminary experiments the authors of the Project have succeeded in the growth of large-size (up to 100 mm in cross section) fianite single crystals; structurally perfect Si and AIIIBV films of high electric parameters on FIANITE substrates, FIANITE films on Si and AIIIBV substrates, as well as “semiconductor-on-FIANITE” multilayer structures. The authors also tested low-temperature molecular-beam epitaxy technique of silicon on the FIANITE. The technique was demonstrated to be promising. New efficient epitaxy technique of AIIIBV compounds on the FIANITE - “capillary epitaxy”, which allows a growth of structurally perfect epitaxy films of high electrophysical parameters, including those of sub-micrometer (= 0.1мm) thickness has been suggested. The obtained results were superior to those published by the other researchers and are rather good reserve for the Project.
Methodically, the activity in scope of the Project will be carried out in the following principal directions:
- development of the technology of large, structurally perfect fianite crystals; development of the technology of the fianite substrates of up to 3” in diameter;
- development of the technology of AIIIBV compounds heteroepitaxial films and multilayer structures on the FIANITE substrates;
- development of the technology of functional thin layers of the FIANITE on Si, Ge and AIIIBV compounds substrates;
- development and manufacturing of pilot samples of the optoelectronic devices based on single and multilayer “semiconductor-fianite” structures; evaluation of operational characteristics of the devices.
With the purpose to grow large-size FIANITE single crystals the technique of directional crystallization of the melt in a cold crucible with direct HF-heating will be used. Epitaxial semiconductor films will be grown by means of molecular-beam and MOCVD epitaxy techniques. Functional FIANITE films will be synthesized using magnetron, laser and electron- and molecular-beam sputtering techniques. The following analytical methods will be used as the main to study the crystals and the films: X-ray diffraction structural and spectral analysis, Raman and optical spectroscopy, optical spectroscopy, optical, electron and atomic-force microscopy, photo- and cathode- luminescence, secondary ion mass-spectroscopy, atomic-emission spectrometry, isotope-oxygen analysis and electro-physical measurements.
Authority researchers from USA, Germany, France and Norway consent to become Official Foreign Collaborators of the Project and express their willingness to take part in the collaborative technological developments, studies of the synthesized materials, tests of the structures and devices and practical implementation of the Project results.
The Project completely meets the ISTC goals because the scientists and specialists previously engaged in the defense industry, development and monitoring of weapons of mass destruction in course of the Project execution will be redirected to peaceful activity – to carry out fundamental and applied studies, development of modern telecommunication technologies and systems for civil industry, development of new optoelectronic technologies and devices, those which will be used in medicine, housekeeping and industry. Thus, the Project is directed on improvement quality of life of entire people.
On the base of novel Hi-Fi FIANITE technologies and structures the pilot samples of optoelectronic devices of new generation with improved reliability and stability of its characteristics will be developed, manufactured and tested, namely: high-sensitive IR arrays and laser photodetectors on InGaAs/FIANITE structures. Germanium code photodiodes with FIANITE protective layer also will be developed. The above devices will be approbated in infrared imagers and in laser systems.
The developments are of high commercial potentialities. In scope of the Project execution purposeful efforts directed to implementation of the results and its commercialization will be made. The objects of the activity will be: the fianite substrates of up to 3” in diameter, “semiconductor-fianite” epitaxial structures possessing instrument parameters and optoelectronic devices based on these structures. Following the Project completion it is planned to set up a specialized enterprise basing upon the participating institutions.