PRINCIPLES OF PRODUCTION OF NEW DEVICES FOR MICRO- AND NANOELECTRONICS ON THE BASE OF MATERIALS WITH ION TRACKS Dissertation zur Erlangung des akademischen Grades DOKTOR-INGENIEUR des Fachbereichs Elektrotechnik und Informationstechnik der FernUniversität in Hagen von ALEXANDER PETROV Minsk/Weißrussland Hagen 2004 ii Eingereicht: 18.05.2004 Mündliche Prüfung: 13.10.2004 1. Berichterstatter: Univ. Prof. Dr. W.R.Fahrner 2. Berichterstatter: Univ. Prof. Dr. G.Gerlach i CONTENTS ABSTRACT .......................................... ................................................... .......... iii INTRODUCTION ................................................... .......................................... 1 Part 1. GENERAL PROPERTIES OF MATERIALS WITH ION TRACKS AND METHODS OF THEIR STUDY 1.1. WORKING MATERIALS 1.1.1. Polymers .......................................... ................................................. 1.1.2. Semiconductors .................................... ............................................ 4 1.1.3. Carbon-based materials ............................ ....................................... 6 14 1.2. TECHNICAL MEANS AND METHODS FOR CHARACTERIZATION OF THE OBTAINED STRUCTURES 1.2.1. Optical microscopy ................................ .......................................... 1.2.2. Scanning electron microscopy ...................... ................................... 17 1.2.3. X-ray diffraction spectroscopy .................... .................................... 23 1.2.4. Ion transmission spectrometry .................... .................................... 29 1.2.5. Electrical measurements ........................... ....................................... 31 47 1.3. ION IRRADIATION 1.3.1. General principles ................................ ............................................ 1.3.1.1. Electrostatic accelerators ............ ............................................... 52 1.3.1.2. High frequency accelerators – cyclotron s .................................. 53 1.3.2. Technologies used in the present research ......... .............................. 56 57 1.4. LATENT ION TRACKS: FORMATION AND PROPERTIES 1.4.1. Physics of ion-solid interaction and track formati on ...................... 1.4.2. Track properties .................................. ............................................. 61 1.4.3. Some applications of latent ion tracks ............ ................................. 69 72 1.5. ETCHED ION TRACKS: FORMATION AND PROPERTIES 1.5.1. Wetting and swelling processes .................... ................................... 1.5.2. Etching of ion tracks ............................. ........................................... 76 1.5.3. Properties of the etched tracks .................. ...................................... 81 88 ii DEPOSITION TECHNIQUES, APPLIED FOR THIS STUDY 1.5.4. Tubules formation by evaporation ................. ................................. 95 1.5.5. Galvanic deposition of matter along etched tracks . ......................... 98 1.5.6. Deposition from a saturated solution .............. ................................. 99 1.5.7. Electrodeless or chemical deposition .............. ................................. 100 PART 2. ION-TRACK-BASED DEVICES FOR MICRO- AND NANOELECTRONICS 2.1. DEVICES ON THE BASE OF POLYMERS 2.1.1. SPECIFIC FEATURES OF THE ION TRACK MANIPULATIONS 2.1.1.1. Metal tubules formation in tracks ................. .......................... 107 2.1.1.2. Thermal behavior of manipulated tracks ............ .................... 127 2.1.2. ION - TRACK – BASED MICRODEVICES 2.1.2.1. Magnets and transformers .......................... ............................ 135 2.1.2.1.1. Micromagnets ..................................... ............................... 142 2.1.2.1.2. Microtransformers ................................ ............................. 147 2.1.2.2. Capacitors......................................... ...................................... 151 2.1.3. ION - TRACK – BASED NANODEVICES 2.1.3.1. Temperature sensors on the base of PET foils ...... ................. 161 2.1.3.2. Pressure sensors on the base of PI foils .......... ........................ 166 2.2. DEVICES ON THE BASE OF SEMICONDUCTORS (TEMPOS) 2.2.1. Basic principles of the TEMPOS ................... ................................. 171 2.2.2. TEMPOS with continuous deposited layers in the trac ks ................ 176 2.2.3. TEMPOS with nanoparticles in the tracks ........... ............................ 181 SUMMARY AND CONCLUSIONS ........................... ...................................... 189 REFERENCES ........................................ ................................................... ........ 192 PUBLICATION LIST ................................. ................................................... ... 212 ACKNOWLEDGEMENTS .................................. ............................................. 218 CURRICULUM VITAE ................................. .................................................. 220 iii ABSTRACT The goal of this work was the investigation of the possibilities of creation of micro- and nanoelectronic devices on the base of th e swift heavy ion tracks, for the sake of the future technology. During the implement ation of the work, the ways of realization of that goal were studied, and some fir st prototypes of ion-track-based micro- and nanoelectronic devices on the base of po lymers and semiconductors were created. Thus, the most important results of t his work are as follows: 1. First prototypes of micromagnets and microtransform ers on the base of PI foils with etched ion tracks have been created. They have been shown to exhibit good quality factors up to ~7 at working frequencie s of about ½ GHz, and reasonable coupling factor of ~90%, respectively; 2. A first prototype of the microcapacitor on the base of PI foil with etched ion tracks has been created. It has shown practically f requency-independent capacity of 0.5 pF - 0.6 pF up to 1 GHz. This resul t was confirmed by a theoretical estimation; 3. According to the studies of temperature and pressur e dependences of resistance of PI and PET polymer foils with fullerite tubules in the ion tracks, it was shown, that temperature and pressure sensors can be created in this way; 4. A family of new electronic devices, denoted by the acronym "TEMPOS" (Tunable Electronic Material with Pores in Oxide on Silicon) has been fabricated for SiO 2/Si and SiON/Si structures with etched ion tracks i n the SiO 2 and SiON dielectric layers. The functioning of the TEMPOS structures is determined not only by the material and the thickne ss of the dielectric layer, but also by the type of silicon substrate, the diam eter, the length, the shape and areal distribution of the etched tracks, and by the type and the distribution of the (semi)conducting matter deposited within these tracks and on the dielectric surface. Two main classes of the TEMPOS devices hav e been studied: (1) the structures with contunuous deposited layers in the tracks, and (2) the structures with nanoparticles in the tracks. It was found that , depending on the TEMPOS iv preparation recipe and electrical working point, th e devices may resemble gatable resistors, capacitors, diodes, transistors, photocells or sensors, and therefore they will be are rather universally appli cable in electronics. TEMPOS structures are often sensitive to temperature, ligh t, humidity and organic gases. Light-emitting TEMPOS structures have been produced as well. About 35 TEMPOS-based circuits such as thermosensors, photos ensors, humidity and alcohol sensors, amplifiers, frequency multipliers, amplitude modulators, oscillators, flip-flops, and many others have been already designed and successfully tested. Relative simplicity and low co st of production together with compact size can be attributed to the advantag es of the TEMPOS structures. In general, it can be concluded from the present re search, that etched ion tracks in polymer foils and silicon-based dielectric layer s can be useful for production of micro- and nanoelectronic devices. A large range of possible applications for these structures can be determined. The present scientifi c and technological state-of-the art makes it possible to realize the creation of th e new ion-track-based devices. v KURZFASSUNG Das Ziel dieser Arbeit war die Untersuchung der Mög lichkeiten der Schöpfung mikro- und nanoeletronischer Strukturen auf der Gru ndlage von Spuren hochenergetischer schneller Ionen für die Technolog ie der Zukunft. Während der Fertigstellung dieser Arbeit wurden die Wege studie rt, wie dieses Ziel realisiert werden kann, und einige allererste Prototypen von i onenspur-basierenden mikro- und naoelektronischen Strukturen wurden auf der Gru ndlage von Polymeren und Halbleitern geschaffen. Die wichtigsten Resultate d ieser Arbeit sind: 1. Es wurden erste Prototypen von Mikromagneten und Mi krotransformatoren in PI-Folien mit geätzten Ionenspuren hergestellt. Es konnte gezeigt werden, daß sie gute Qualitätsfaktoren biz zu ~7 bei Arbeitsfrequenzen in der Größenordnung von etwa ½ GHz haben, bzw. daß sie se lbst bei GHz- Frequenzen noch zufriedenstellende Kopplungsfaktore n von etwa 90% aufweisen. 2. Die Studien über Temperatur-und Druckabhängigkeit der Widerstände von Fullerit-Röhrchen in PI-und PET-Folien zeigten, daß auf diese Weise Temperatur-und Drucksensoren hergestellt werden kön nen. 3. Eine Familie neuartiger Bauelemente, durch das Akro nym: „TEMPOS“ (Tunable Electronic Material