Relaxation and Crystallization of Amorphous Silicon PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Relaxation and Crystallization of Amorphous Silicon PDF full book. Access full book title Relaxation and Crystallization of Amorphous Silicon by Sjoerd Roorda. Download full books in PDF and EPUB format.
Author: Sjoerd Roorda Publisher: ISBN: Category : Silicon Languages : en Pages : 0
Book Description
The history of amorphous silicon (a -Si) dates back to the early days of ion implantation into crystalline silicon (c-Si)1 and to the pioneering experiments on vacuum deposition2, both roughly two decades ago. Studies of its properties and behaviour upon various (heat-) treatments have been carried out ever since, especially in relation to crystallization and solid -phase epitaxy. A boost in research activities occurred around 1975, when it became clear that a -Si in its hydrogenated form (a-Si:H) shows semiconducting properties and can be used as a semiconductor in devices3. a -Sill differs in many respects from its 'clean' counterpart a -Si, but fundamental questions concerning the atomic structure are similar for the two types of material. It was only after the first reports on pulsed -laser annealing in1975, that the possibility of melting (ion implanted) a -Si became an issue4. In the years following this discovery of damage repair by pulsed -laser irradiation, it was suggested that the process does not involve simple thermal melting5 but rather the formation of a high -density electron -hole plasma. In the latter picture, the temperature of the Si lattice does not rise to the melting temperature6. More recently, there is general consensus that indeed a -Si can be melted by pulsed -laser irradiation7.The temperature at which melting occurs, however, still poses major questions. In 1978 Bagley and Chen8a and Spaepen and Turnbull8b predicted that the melting temperature of a -Si should be considerably (> 200 K) lower than that ofc -Si (1685 K). Their prediction was based on calculations of the Gibbs free energy vs. temperature of a -Si and liquid Si (/-Si), in comparison to that of c -Si. Experimental indications for a difference in melting temperature were found in 1980 by Baeri et al.9 who studied pulsed electron beam heating of a -Si. Experiments on continuous wave (cw) laser heating10 and on line -source electron beamheating11, in contrast, did not show any significant difference: solid -phase epitaxial regrowth of a -Si was found to occur even at temperatures relatively close to the melting temperature of c -Si. Subsequently, Thompson et a/.12 performed experiments on nanosecond pulsed -laser induced melting of a -Si and showed convincingly that under those circumstances the material melts at .--200 K below the c -Si melting temperature. Their conclusion is now widely accepted, even though elaborate cw laser heating experiments by Olson et al.13,14 still have not shown any such melting point lowering. In this chapter we will discuss recent measurements of structural changes ina -Si upon laser- and thermal treatments. Some of these will be presented in the remainder of part I of this thesis. The implications of these measurements for the controversy concerning the melting temperature of a -Si will be discussed.
Author: Sjoerd Roorda Publisher: ISBN: Category : Silicon Languages : en Pages : 0
Book Description
The history of amorphous silicon (a -Si) dates back to the early days of ion implantation into crystalline silicon (c-Si)1 and to the pioneering experiments on vacuum deposition2, both roughly two decades ago. Studies of its properties and behaviour upon various (heat-) treatments have been carried out ever since, especially in relation to crystallization and solid -phase epitaxy. A boost in research activities occurred around 1975, when it became clear that a -Si in its hydrogenated form (a-Si:H) shows semiconducting properties and can be used as a semiconductor in devices3. a -Sill differs in many respects from its 'clean' counterpart a -Si, but fundamental questions concerning the atomic structure are similar for the two types of material. It was only after the first reports on pulsed -laser annealing in1975, that the possibility of melting (ion implanted) a -Si became an issue4. In the years following this discovery of damage repair by pulsed -laser irradiation, it was suggested that the process does not involve simple thermal melting5 but rather the formation of a high -density electron -hole plasma. In the latter picture, the temperature of the Si lattice does not rise to the melting temperature6. More recently, there is general consensus that indeed a -Si can be melted by pulsed -laser irradiation7.The temperature at which melting occurs, however, still poses major questions. In 1978 Bagley and Chen8a and Spaepen and Turnbull8b predicted that the melting temperature of a -Si should be considerably (> 200 K) lower than that ofc -Si (1685 K). Their prediction was based on calculations of the Gibbs free energy vs. temperature of a -Si and liquid Si (/-Si), in comparison to that of c -Si. Experimental indications for a difference in melting temperature were found in 1980 by Baeri et al.9 who studied pulsed electron beam heating of a -Si. Experiments on continuous wave (cw) laser heating10 and on line -source electron beamheating11, in contrast, did not show any significant difference: solid -phase epitaxial regrowth of a -Si was found to occur even at temperatures relatively close to the melting temperature of c -Si. Subsequently, Thompson et a/.12 performed experiments on nanosecond pulsed -laser induced melting of a -Si and showed convincingly that under those circumstances the material melts at .--200 K below the c -Si melting temperature. Their conclusion is now widely accepted, even though elaborate cw laser heating experiments by Olson et al.13,14 still have not shown any such melting point lowering. In this chapter we will discuss recent measurements of structural changes ina -Si upon laser- and thermal treatments. Some of these will be presented in the remainder of part I of this thesis. The implications of these measurements for the controversy concerning the melting temperature of a -Si will be discussed.
Author: Leonardus Bimo Bayu Aji Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Amorphous silicon (a-Si) is a material of major scientific and technological interest. It has been a very active topic of investigation for several decades, frequently crossing the border between physics and materials science. Research has been motivated partly by the fact that a-Si is an excellent model of a covalently bonded continuous random (CRN) network; thus a detailed understanding of the structure and properties of this material may aid the understanding of many other disordered materials. Notwithstanding many years of research and widely accessible experimental techniques, the structural properties of as-implanted a-Si and its relaxation mechanism remain poorly understood and are indeed subject of lively debate. This thesis addresses this issue by looking at the transition from unrelaxed to relaxed states which may provide insight into the nature of the structural relaxation process. In all three forms of a-Si studied: ion-implanted, pressure-induced, and re-irradiated relaxed a-Si, analysis of Raman spectra indicated a local ordering of the material approaching a continuous random network in the fully relaxed material due to thermal annealing. The bond-angle distortion is found to reduce at temperatures above 250 degree Celsius, whereas previous studies show reduction below this temperature. Electrical conductivity measurements of ion-implanted a-Si showed a decrease in the number of dangling bonds upon annealing. This phenomenon is observed during low temperature annealing up to 250 degree Celsius, before the bond-angle ordering commenced. Differential scanning calorimetry measurements show a heat release during low temperature annealing that is predominately due to defect annealing from the structure, but the heat release continues up to annealing temperature where the bond-angle distortion is reduced. Indentation tests showed that the transition in the deformation mechanism in ion-implanted a-Si mechanism from plastic to phase transformation related to the reduction of defects in the structure. This transition occurred at annealing temperatures before the bond-angle distortion reached its minimum value. The effect of in-diffused hydrogen upon annealing was also extensively investigated in this current study. It is observed that in-diffused hydrogen does not contribute significantly to the short-range ordering and hence structural relaxation. Finally, the results from all studies, namely Raman spectroscopy, electrical measurements, calorimetry, and indentation are brought together to develop a new model for structural relaxation in a-Si. Broadly, it is found that there are two main steps in structural relaxation: defect removal at low temperatures up to 250 degree Celsius, which is accompanied by significant heat release, and a reduction in bond-angle distortion at higher temperatures, where the amount of heat release is smaller. In terms of existing models, the current findings are consistent with elements of the previous defect/lattice strain models but differ in that a more distinct separation of defect removal and reduction in strain (bond-angle distortion) is found in the present study.
Author: Norbert H. Nickel Publisher: Academic Press ISBN: 0080540945 Category : Technology & Engineering Languages : en Pages : 215
Book Description
This book on the Laser Crystallization of Silicon reviews the latest experimental and theoretical studies in the field. It has been written by recognised global authorities and covers the most recent phenomena related to the laser crystallization process and the properties of the resulting polycrystalline silicon. Reflecting the truly interdisciplinary nature of the field that the series covers, this volume will continue to be of great interest to physicists, chemists, materials scientists and device engineers in modern industry. Valuable applications for industry, particularly in the fabrication of thin-film electronics Each chapter has been peer reviewed An important and timely contribution to the semiconductor literature
Author: Akira Kohyama Publisher: John Wiley & Sons ISBN: 1118406028 Category : Technology & Engineering Languages : en Pages : 400
Book Description
This transactions volume contains 33 papers from the CREST International Symposium on SiC/SiC Composite Materials Research and Development and Its Application to Advanced Energy Systems held May 20-22, 2002 in Kyoto, Japan. Chapters include Processing for SiC/SiC Composites; Processing for SiC/SiC Composite Constituent; Characterization of Thermomechanical Performance; and Joining Technologies for Advanced Energy Applications. 373 pages.
Author: Hellmut Fritzsche Publisher: World Scientific ISBN: 981453191X Category : Science Languages : en Pages : 1153
Book Description
This book presents the most recent important ideas and developments in the field of Hydrogenated Amorphous Silicon and related materials. Each contribution is authored by an outstanding expert in that particular area.
Author: Zumin Wang Publisher: CRC Press ISBN: 9814463418 Category : Science Languages : en Pages : 317
Book Description
Crystalline semiconductors in the form of thin films are crucial materials for many modern, advanced technologies in fields such as microelectronics, optoelectronics, display technology, and photovoltaic technology. Crystalline semiconductors can be produced at surprisingly low temperatures (as low as 120C) by crystallization of amorphous semicon
Author: Sjoerd Roorda
Author: Sjoerd Roorda
Author: Leonardus Bimo Bayu Aji
Author: Onno B. Loopstra
Author: Norbert H. Nickel
Author: Onno Bram Loopstra
Author: Matthew Libera
Author: Akira Kohyama
Author: Brenda D. King
Author: Hellmut Fritzsche
Author: Zumin Wang