The goal of this dissertation is the study and characterisation of high dose Carbon (C) implantation processes into Silicon (Si) and related materials for the synthesis of Silicon Carbide (SiC). The attainment of well-characterised multilayer structures useful to fabricate sensor and electronic devices based on them constitutes the main objective of this work.SiC constitutes a very promising semiconductor, thermally and chemically stable with excellent physical properties, which has started to be successfully applied in some of the most outstanding fields in electronics. Electronic devices of SiC can operate at high temperatures, in chemically aggressive conditions and even under extreme radiation, dissipating heat excesses, and as a result, proportioning enormous benefits over electronic devices based on the other available semiconductors. Among the amount of applications, the optoelectronic, high temperature electronic, hard radiation electronic, high power and high frequency devices are worth remarking. Operable devices such as three colour LEDs, power MOSFETs, bipolar transistors, photodiodes or rectifiers have successfully been fabricated. Additionally, the high mechanical and chemical stability, and the high stiffness of SiC in relation to Si, are also interesting properties to develop complete Micro-Electro-Mechanical systems (MEMS), where sensing devices, signal processing and even actuators are integrated in the same substrate.The synthesis of good quality and cheaper SiC structures is required to develop its technology. This implies the growth of SiC on the cheap and useful Si substrate. The traditional methods for obtaining SiC have been CVD and MBE, but some drawbacks such as the degree of reproducibility and the higher temperatures used in these processes can constitute a problem. In this sense, ion implantation constitutes a suitable alternative process for the direct synthesis of SiC, totally compatible with Si technology. This technique allows a high degree of control in the synthesis, offering enormous possibilities for obtaining complex structures.By ion implantation, the properties of the synthesised material strongly depend on the implantation and annealing parameters. The perfect design of the implantation process will have repercussions on the characteristics of the resulting structure. Moreover, the amount of implanted C plays an important role in the way in which C is incorporated in the system. The incorporated C can take different places in de Si network, what will finally affect the structural characterisation of the synthesised material.A complete group of analysis techniques has been used in order to characterise adequately the materials studied along this work. Among them, it may be mentioned the Raman and FTIR spectroscopies, mainly used in structural studies and to determine phases, XPS, which has allowed the measurement of the in-depth implanted C distribution and the study of the different bond configurations in the implanted layer, and finally TEM, which is used for the direct observation of the synthesised structures. The interpretation of all these data makes it possible to deep in the knowledge of the physical mechanisms involved in these processes.As far as the contents are concerned, the thesis is structured in five chapters, each one containing its own references to other works. The introductory part, chapter 1, is divided in sections. The first one contains all the basic data related to SiC. The second section deals with the ion implantation as a method of SiC synthesis. A description of the analysis techniques used along this work is presented in the last section.Chapter 2 is devoted to the synthesis and recrystallisation of amorphous SiC. Previously, it has been studied the behaviour of the 6H-SiC commercially available in front of implantation processes, taking into account the role played by the temperature of implantation, the implanted dose and the temperature of annealing. Once performed this characterisation, the study of amorphous Si implanted with C at room temperature (RT) is carried out. The detailed disposition of existing chemical bonds as a function of the amount of introduced C has been an object of interest. Finally, the recrystallisation of this material by thermal processes and by IBIEC (a dynamic process that involves high-energy implantation) has been considered.The direct synthesis of crystalline SiC by C implantation in a Si crystalline substrate is the subject of chapter 3. The procedure is to implant at a high enough temperature, 500°C, to avoid the Si amorphisation. This part of the chapter has been divided attending to the value of the implanted dose. Firstly, samples implanted at doses below the threshold dose needed to reach a stoichiometric SiC composition at the implanted peak have been analysed. The study of these samples has allowed to characterise the main processes involved in the ion beam synthesis of crystalline SiC. Then, a multiple step implantation has been defined to obtain a continuous stoichiometric SiC layer. The analysis of the implanted samples has corroborated the formation of such a layer, with abrupt interfaces with the surface and substrate Si regions.Chapter 3 finishes with a detailed study of the etch-stop properties of the ion beam synthesised layers. The excellent etch selectivity between these layers and the Si regions has allowed the fabrication of test micromechanic structures such as membranes, bridges and other self-standing simple structures. The attainment of these kinds of structures based on the ion beam synthesised layers constitutes an important conclusion, as it demonstrates its ability for the development of micromachined devices.The study of the ion beam synthesis of SiC is extended to SiGe substrates in Chapter 4. In principle, the aim of this study is to improve the understanding of the mechanisms involved, in order to determine the influence of parameters such as the chemical composition, strain and bond length of the target material. Moreover, the possible modification of the synthesised phases by the incorporation of Ge atoms in a Si(x_y)Ge(x)C(y) ternary alloy is also investigated.This study is performed in a way similar to that previously done in Si. Firstly, the synthesis and recrystallisation of amorphous layers is investigated. After that, the analysis of high temperature processes in crystalline substrates is performed.Finally, some general conclusions are written in chapter 5.

Quan es planteja la possibilitat d'implantació d'un mercat de futurs i opcions sobre bestiar en viu es requereix conèixer les implicacions que comporten i, a més a més, els condicionants de l'entorn per determinar la idoneïtat de la seva implantació.En aquesta investigació, en primer lloc, és realitza una anàlisi dels principals mercats de futurs i opcions sobre bestiar en viu, investigant l'origen i l'evolució que han tingut, les causes que han propiciat la situació actual i, a la vegada, identificant tots els contractes de futurs i opcions sobre bestiar en viu que s'han comercialitzat i que es comecialitzen actualment. En segon lloc, s'analitza l'eficiència dels mercats de futurs sobre bestiar en viu -a partir d'investigacions realitzades, sobretot, als EUA- tot i que el concepte d'eficiència, en aquest context, no ha estat sempre el mateix al llarg dels anys, ja que han variat les situacions socioculturals. Malgrat que en molts estudis s'han arribat a conclusions poc contundents i, en ocasions, contradictòries entre elles, d'acord amb la majoria de les investigacions s'ha trobat que aquests mercats són eficients, tant en l'accepció clàssica com en l'accepció global.Tanmateix, cada un dels aspectes relacionats amb l'eficiència en l'accepció global s'analitzen individualment. És a dir, s'analitza la capacitat de predicció dels preus d'aquests contractes, les implicacions de les estratègies de cobertura de bestiar en viu, la reacció dels preus d'aquests contractes a la nova informació, la integració i la relació dominant-satèl·lit entre els mercats de futurs sobre bestiar en viu i els mercats al comptat, les implicacions del comportament dels operadors d'aquests mercats i, finalment, el problema del lliurament d'aquests contractes.En tercer lloc, s'analitzen les repercussions dels mercats d'opcions sobre contractes de futurs que tenen com a producte subjacent bestiar en viu. En quart lloc, amb els resultats de l'anàlisi de l'eficiència dels mercats de futurs sobre bestiar en viu i de les repercussions de les opcions, s'analitzen els beneficis potencials que podria reportar la implantació d'un mercat d'aquestes característiques en territori català.Tanmateix, els beneficis d'un mercat de futurs i opcions només es poden produir si el mercat té una bona acceptació i els contractes tenen èxit. En cinquè lloc, doncs, s'analitzen les causes dels èxits i fracassos d'aquest tipus de contractes i el procés d'innovació que segueixen aquests mercats. En sisè lloc, s'analitzen els condicionants que es tenen en el territori català per la implantació d'un mercat de futurs sobre bestiar en viu aprofundint, sobretot, els condicionats que fan referència a l'entorn productiu del bestiar: l'emmagatzemabilitat o el procés de formació de preus; la homogeneïtat; la variabilitat de preus; la importància econòmica i la competitivitat del mercat; l'existència de contractes a termini; el risc de Base d'altres contractes; els costos de liquiditat; l'estructura i l'activitat del mercat.Finalment, es fan propostes sobre les característiques que haurien de tenir els contractes de futurs i els contractes d'opcions sobre bestiar en viu, així com sobre les característiques del mercat, en base a totes les anàlisis realitzades, per garantir un bon funcionament i l'èxit dels contractes. / When it is planning the possibility of implantation of one livestock futures and options market, it is necessary to know the implications that they have and, over-more, the condicionants of the territory in order to determine if that implantation is adequate.In this investigation, in the first place, an analysis of the main livestock futures and options markets has been realised, determining the origin and the evolution that they have been, the factors that have contributed to the nowadays situation and also identifying all the futures and options contracts they have been traded.Secondly, it has been analysed the livestock futures markets efficiency, according to investigations realised mostly in the USA. Nevertheless, the efficiency concept, in this context, has changed over the time.Every aspect related to the efficiency has also been analysed. That is to say, the forecasting capacity of these contracts prices, the implications of the hedges strategies, the prices reaction to new information, the integration and the dominant-satellite relationship between the futures and the cash markets, the implications of the operator's behaviour of these markets and, finally, the problem of the delivery of these contracts.In the third place, the repercussions of the options markets over the futures contracts who have as underlying product the livestock have been analysed.Fourthly, based in the results of the efficiency analysis of the futures markets and the repercussions of the options contracts, it has been analysed the potential benefits that could offer the implantation of one of these markets in the catalan territory.Nevertheless, the benefits of one futures and options market only can be obtained if the market has a good acceptance and the contracts have success. So, In the fifth place, it has been analysed the factors that can contribute to the success or failure of these contracts and the innovation process these markets follow.In the sixth place, the condicionants or the catalan territory have been analysed in order to implant a futures and options market, putting an especial interest in the livestock production environment: the storage capacity or the price discovery process, the homogeneity, the price's variability, the importance and the competitiveness of the market, the existence of forward contracts, the Basis risk of other contracts, the liquidity costs, the structure and the activity of the market. Finally, proposals about the appropriate characteristics of the futures and options contracts and also about the market have been presented, based in all the previous analysis, in order to guarantee a good performance and the success of the contracts.

Material addicional: http://hdl.handle.net/10230/20652 / En aquesta tesi es duu a terme una anàlisi de la implantació de la terminologia en l’ús amb l’objectiu de trobar les causes que expliquen l’èxit o el fracàs de les propostes denominatives. Partim de la premissa que existeix un conjunt de factors que influencien positivament o negativament la implantació terminològica. En aquest treball estudiem la implantació en l’ús de la terminologia normalitzada de l’àmbit de la informàtica i les tecnologies de la informació i la comunicació (TIC) en un corpus especialitzat. Establim una metodologia de treball que ens permet d’obtenir dades quantitatives i qualitatives per a la recerca de factors d’implantació i, a continuació, ens proposem d’estudiar-ne alguns, que tenen a veure amb aspectes lingüístics (brevetat de les denominacions i acostament formal i semàntic amb el terme original), socio¬lingüístics (àmbit d’ús de la terminologia, via d’entrada dels termes en un àrea temàtica determinada i concurrència terminològica) i procedimentals (difusió dels termes a través de diccionaris generals i especialitzats). L’anàlisi ens proporciona dades empíriques per confirmar que alguns dels aspectes àmpliament tractats en la bibliografia són efectivament factors d’implantació. / This work presents a terminology implantation analysis with the aim to find the causes explaining the success or failure of terms in real language use. We depart from the premise that there are factors which influence terminology implantation in a positive o negative way. Our study analyses the implantation of standardised terms of Computer Science and Information and Communication Technologies (ICT) in a specialised corpus. We establish a specific methodology in order to obtain quantitative and qualitative data for the research of implantation factors. In this work we study some of these factors, especially those related with linguistic aspects (brevity of terms and formal and semantic proximity to the original term), sociolinguistic aspects (field of use, entry of terms in a specific domain and terminological competition) and procedural aspects (term dissemination through general and specialised dictionaries). The results obtained provide empirical data to confirm some of the aspects widely discussed in the literature as real implantation factors.