Zugl.: München, Univ. der Bundeswehr, Diss., 2009

Techn. Universiẗat, Diss., 2005--Berlin.

Though the concept of junctionless field effect transistor (JLFET) is old, it was not possible to fabricate a useful JLFET device, as it requires a very shallow channel region. Very recently, the emergence of new and advanced technologies has made it possible to create viable JLFET devices using nanowires. This work aims to computationally investigate the interplay of quantum size-quantization and random dopant fluctuations (RDF) effects in nanoscale JLFETs. For this purpose, a 3-D fully atomistic quantum-corrected Monte Carlo device simulator has been integrated and used in this work. The size-quantiza¬tion effect has been accounted for via a param¬eter-free effec¬tive potential scheme and benchmarked against the NEGF approach in the ballistic limit. To study the RDF effects and treat full Coulomb (electron-ion and electron-electron) interactions in the real-space and beyond the Poisson picture, the simulator implements a corrected-Coulomb electron dynamics (QC-ED) approach. The essential bandstructure and scattering parameters (energy bandgap, effective masses, and the density-of-states) have been computed using an atomistic 20-band nearest-neighbour sp3d5s* tight-binding scheme. First, an experimental device was simulated to evaluate the validity of the simulator. Because of the small dimension, quantum mechanical confinement was found to be the dominant mechanism that significantly degrades the current drive capability of nanoscale JLFETs. Surface roughness scattering is not as prominent as observed in conventional MOSFETs. Also, because of its small size, the performance of the device is prone to the effect of variability, for which a discrete doping model was proved essential. Finally, a new JLFET was designed and optimized in this work. The proposed device is based on a gate-all-around silicon nanowire. Source/drain length is 32.5 nm and channel length is 14 nm. Gate contact length is 9 nm. The EOT (equivalent oxide thickness) is 1 nm. It has a metal gate with a workfunction of 4.55 eV. The source, channel and drain regions are n-type with a doping density of 1.5×1019 cm-3. Detailed simulation shows that the two most influential mechanisms that degrade the drive capability are quantum mechanical confinement and Coulomb scattering. Surface roughness scattering is found to be very weak. In addition, thinner nanowire is more prone to Coulomb scattering exhibiting a reduced ON-current (ION). Simulation results show that silicon nanowires with a side length (width and depth) of 3 nm and a doping density of 1.5×1019 cm-3 produce satisfactory drive current.

Tunnel à effet de champ (TFET) et un nouveau composant MOS à rétroaction que nous avons nommé le Z2-FET.Le Z2-FET est envisagé pour la logique faible consommation et pour les applications mémoire compatibles avecles technologies CMOS avancées. Nous avons étudié de manière systématique des TFETs avec différents oxydesde grille, matériaux et structures de canal, fabriqués sur silicium sur isolant totalement déserté (FDSOI). Lesmesures de bruit à basse fréquence (LFN) sur TFETs montrent la prédominance d'un signal aléatoiretélégraphique (RTS), qui révèle sans ambiguïté le mécanisme d’effet tunnel. Un modèle analytique combinantl’effet tunnel et le transport dans le canal a été développé, montrant un bon accord entre les résultatsexpérimentaux et les simulations.Nous avons conçu et démontré un nouveau dispositif (Z2-FET, pour pente sous le seuil verticale et zéroionisation par impact), qui présente une commutation extrêmement abrupte (moins de 1 mV par décade decourant), avec un rapport ION / IOFF >109, un large effet de hystérésis et un potentiel de miniaturisation jusqu'à 20nm. La simulation TCAD a été utilisée pour confirmer que la commutation électrique du Z2-FET fonctionne parl'intermédiaire de rétroaction entre les flux des électrons et trous et leurs barrières d'injection respectives. LeZ2-FET est idéalement adapté pour des applications mémoire à un transistor. La mémoire DRAM basée sur leZ2-FET montre des performances très bonnes, avec des tensions d'alimentation jusqu'à 1,1 V, des temps derétention jusqu'à 5,5 s et des vitesses d'accès atteignant 1 ns. Une mémoire SRAM utilisant un seul Z²-FET estégalement démontrée sans nécessité de rafraichissement de l’information stockée.Notre travail sur le courant GIDL intervenant dans les MOSFETs de type FDSOI a été combiné avec leTFET afin de proposer une nouvelle structure de TFETs optimisés, basée sur l'amplification bipolaire du couranttunnel. Les simulations de nouveau dispostif à injection tunnel amélioré par effet bipolaire (BET-FET) montrentdes résultats prometteurs, avec des ION supérierus à 4mA/��m et des pentes sous le seuil SS inférieures à 60mV/dec sur plus de sept décades de courant, surpassant tous les TFETs silicium rapportés à ce jour.La thèse se conclut par les directions de recherche futures dans le domaine des dispositifs à pente sous leseuil abrupte. / This thesis is dedicated to studying sharp switching devices, including the tunneling field-effect-transistor(TFET) and a new feedback device we have named the Z2-FET, for low power logic and memory applicationscompatible with modern silicon technology. We have extensively investigated TFETs with various gate oxides,channel materials and structures, fabricated on fully-depleted silicon-on-insulator (FD-SOI) substrates.Low-frequency noise (LFN) measurements were performed on TFETs, showing the dominance of randomtelegraphy signal (RTS) noise, which reveals the tunneling mechanism. An analytical TFET model combiningtunneling and channel transport has been developed, showing agreement with the experimental and simulationresults.We also conceived and demonstrated a new device named the Z2-FET (for zero subthreshold swing andzero impact ionization), which exhibits extremely sharp switching with subthreshold swing SS < 1 mV/dec,ION/IOFF current ratio reaching 109, gate-controlled hysteresis and scalability down to 20 nm. The Z2-FEToperates with feedback between carriers flow and their injection barriers. The Z2-FET is used for one-transistordynamic random access memory (DRAM) with supply voltage down to 1.1 V, retention time up to 5.5 s andaccess speed reaching 1 ns. The static RAM (SRAM) application is also demonstrated without the need ofrefreshing stored data.Following our work on gate-induced drain leakage (GIDL) current in short-channel FD-SOI MOSFETs andon TFET operating mechanisms, we propose a new class of optimized TFETs with enhanced ION, based on thebipolar amplification of the tunneling current. Simulations of the bipolar-enhanced tunneling FET (BET-FET),combining the TFET with a heterojunction bipolar transistor, show promising results, with ION > 4×10-3 A/��mand SS < 60 mV/dec over 7 decades of current, outperforming all silicon-compatible TFETs reported to date.The thesis concludes with future research directions in the sharp-switching device arena.

Magister Educationis (Adult Learning and Global Change) - MEd(AL) / This paper documents a case study of the Innovation and Development Divisions of two public FET Colleges. The research asked the following question:How do FET College educators explain the role and function of college occupational training units. / South Africa

Magister Commercii (Industrial Psychology) - MCom(IPS) / Research on stress has indicated that people in the helping professions dealing with people, especially those in the teaching profession, are particularly prone to emotional distress. However, information regarding the stress-related emotions specifically experienced by academic lecturers at institutions of Further Education and Training is not abundant. University teaching has traditionally been conceived of as a relatively stress-free occupation, or at least has been seen in this way by outsiders. Nevertheless, there is overwhelming evidence attesting to the fact that academia is a highly stressful occupation.The contemporary academic context in South Africa is characterised by changes such as the incorporation of colleges and the merging of universities and technikons, now referred to as universities of technology. Consequences such as financial predicaments, insecurity of employees, short-term contract positions, fewer fringe benefits, increasing emotional disturbance and stress, are unavoidable. Although they are not highly paid in comparison to professionals in the commercial sector, academics have been envied for their tenure, light workloads, flexibility and freedom to pursue their own research.Concerns about academic stress have been articulated over the past three decades. Research conducted in the United Kingdom (UK), United States of America (USA), Australia and New Zealand has identified several key stressors commonly associated with stress among academic staff. These include work overload, time constraints, lack of promotion opportunities, inadequate recognition, inadequate salary, changing job role, inadequate management and/or participation in management, inadequate resources and funding and student interactions. Other sources of stress, such as high self-expectations, poor interactions with colleagues, inequality in the system and lack of regular performance feedback have been highlighted in a few studies. Although some studies found high levels of stress relating to work relationships, control, resources and communication and job insecurity, excessive overload and work-life imbalance are among the most frequently reported stressors by academics. Since academics do not represent an homogeneous group of professionals, it is considered inappropriate to examine academic stress without taking all their professional and personal characteristics into account. Research has shown that workload, inadequate salaries and a lack of public recognition were perceived as more significant sources of pressure by men than by women, whilst job insecurity, isolation from colleagues, a lack of institutional recognition of worth and work politics were more salient for women. Since academia is still largely a male dominated occupation, female academics may experience more stressors and strains than their male counterparts due to a lack of role models, less socialisation from women from their own rank, gender stereotypes and increased role conflict as they endeavour to balance roles at work and at home. Researchers have also noted the importance of age-based differences, and conventionally believe that stress universally declines with chronological age.Data was collected through a biographical questionnaire and the Experience of Work and Life Circumstances Questionnaire (WLQ). A convenience sample of lecturers in an FET College (n=150) completed the questionnaires, which were analysed using the Statistical Package for the Social Sciences (SPSS), version 20. Statistical procedures for data analysis include: T-Test, Multiple Regression Analysis and Analysis of Variance (ANOVA).The results in the current research reveal that there are statistically significant differences in stress levels of academic staff at the FET college based on gender, age, race, marital status and tenure. Based on the responses obtained, 35.33% of the variance in total stress could be explained by Organisational functioning, Task aspects, Salary, benefits and personnel policies, Extra-organisational factors and Career aspects, and suggest that other unexplored variables could explain the variance in stress levels experienced by academics at the FET college.

Synen på kroppar och kroppsideal har förändrats i det svenska samhället. Feta kroppar passar inte in i dagens kroppsideal som synliggörs främst genom media. Däremot har feta kroppar ansetts som ett problematiskt fenomen en relativ kort tid. Mycket av tidigare forskning om kroppsideal lägger större vikt på barn i högre årskurser vilket gör det relevant att undersöka ämnet även i mellanstadiet då förhållandet till den egna kroppen är en viktig del av en växande persons självbild. Lärare förmedlar oundvikligt normer i undervisningen och därför är det viktigt att vara medveten om sina explicita och implicita värderingar om hur en kropp ska se ut. Syftet med denna studie var att öka kunskapen om lärares uppfattningar om kroppsideal samt om sitt arbete med kroppsideal i undervisningen. Det undersöks även hur lärares svar kan tolkas ur ett normkritiskt perspektiv. Studiens teoretiska utgångspunkt var den normkritiska teorin och data insamlades genom semistrukturerade intervjuer med fokus på lärarnas egna tankar och åsikter. Analysen av intervjuerna resulterade i åtta olika underteman. Det som framkom var att samhällets kroppsideal om en vältränad och/ eller smal kropp reflekteras i lärarnas syn på kroppsideal, och att de uppgav att kränkningar mot feta kroppar förekom på deras skolor. Lärarnas syn på orsaker till övervikt var att den huvudsakligen beror på kost- och träningsvanor och de uppfattade övervikt som något problematiskt och ohälsosamt. De flesta av de intervjuade lärarna försökte väva in innehållet kroppsideal i undervisningen men uttryckte en viss osäkerhet och problematik kring detta. Lärarna uppvisade även varierande åsikter om innehållets relevans i mellanstadiet trots att kroppsideal står med i läroplanens kunskapskrav för årskurs 4–6. Det var dock svårt att dra slutsatser från materialet rörande om lärarna gav uttryck för normkritiska förhållningssätt till kroppsideal, samt om de erbjöd eleverna en mer nyanserad bild av hur olika kroppar kan se ut i undervisningen.

A dissertation submitted to the Faculty of Education in fulfilment of the requirements for the Degree of Doctor of Education in the Department of Curriculum and Instructional Studies at the University Of Zululand, 2016 / The inclusion of the subject, Life Orientation, in the school curriculum for a democratic education dispensation was the realisation of the recommendation of the National Education Crisis Committee or NECC (1992) in its research for a curriculum model for a post-apartheid society (CUMSA) and Educational Renewal Strategy (ERS). The NECC (1992: 79) emphasised that lifestyle education was essential for a post-apartheid curriculum in order to incorporate knowledge of and guidance on religion, economic education and physical education, to be directed at norms, values, personal convictions and attitude to life (including an emphasis on openness to and acceptance of the convictions and attitudes of others). However, studies have highlighted that Life Orientation is generally considered an appendage, an additional subject that is perceived as being of lesser importance in the school curriculum (Chisholm, 2000; Jansen, 1997; Christie, 1999). Such claims are based on the following facts: Life Orientation has the least number of periods in the school timetable; there is no formal assessment of the Life Orientation knowledge, skills, values and attitudes; learners’ performance in Life Orientation counts for less on their school-leaving certificates, than their performance in other subjects; and there is no accountability on the part of teachers with regard to learners’ performance in the subject. Therefore, results obtained in the subject do not add value in the certification process of the learner in the Further Education and Training (FET) Band. While reforms and changes have been introduced in the South African schooling curriculum for a democratic political and social dispensation, educational researchers (Chisholm, 2000; Jansen, 1997; Christie, 1999) have highlighted the challenges facing the successful implementation of the new curriculum. This study considers the mediation of the subject curriculum to be the main challenge in the successful implementation of the national curriculum statement, which provides teachers with guidelines on why, what and how classroom practice ought to be. Through the lens of the tuition of a specific subject, this study considers the competence of teachers in mediating Life Orientation in the FET Phase. This study attempted to answer the following research questions: • What paradigm informs the mediation strategies of teachers of Life Orientation? • How do teachers’ mediation strategies align content, intended outcomes and assessment for daily learning activities? • Why do teachers perceive their mediation strategies as being congruent with the attainment of the Life Orientation curriculum statement and learning outcomes? This study targeted teachers involved in the teaching of Life Orientation in the FET Phase: that is, Grades 10, 11 and 12 teachers in schools in the vicinity of the Pinetown District. A mixed method design was used to investigate teachers’ perceptions and competencies in teaching Life Orientation in the Further Education and Training band. Both quantitative and qualitative data collection instruments were used to collect data from the participants. The researcher used open-ended questionnaires for data collection with regard to the perspectives on a mediating role for the effective teaching of Life Orientation in the FET band. The research was conducted with Grades 10, 11 and 12 Life Orientation (L.O.) teachers. There are 167 secondary schools under Pinetown District and the questionnaires were administered in 30 of the 167 secondary schools. A total of 60 teachers, that is, 2 teachers per school, teaching Grades 10, 11 and 12 were used as respondents to the questionnaires in order to answer the research question. The purpose of the survey questionnaire was to collect information regarding L.O.’s academic value, L.O. teachers’ preparedness and L.O. mediation strategies. Interviews were also used to collect qualitative data from the participants who were teachers who teach Life Orientation in the FET phase. According to McMillan and Schumacher (2010), in-depth interviews use open-response questions to obtain data on participants’ meanings regarding how individuals conceive of their world and how they explain or make sense of the important events in their lives. According to the collected data, the participants felt very strong about the importance and the academic value of the subject LO in the FET curriculum. They emphasised that the subject was invaluable in the effective teaching of the learners at this stage in order to prepare them for future careers and as future citizens. They felt a need for the subject to be recognised and to be treated with some degree of the value it deserves within the curriculum. It was mentioned by the participants that the teachers who teach the subject have to be well-prepared and trained, and also that they need to have a specialised knowledge and understanding for the effective teaching and learning of the subject to happen. Over and above they have to be passionate about the subject, and be willing to sacrifice their time and talents to develop themselves and to teach better. A variety of mediation strategies that are learner-centred were identified as the best strategies to teach the subject, in order to improve and develop learner knowledge and understanding around the subject. Strategies that keep learners fully involved in their learning and development were seen as the best strategies. Participants felt that learners learn better when they find information on their own and when they interact with others to develop knowledge and understanding. This study recommends that Life Orientation must be treated in the same manner as other subjects in the curriculum and that this needs to be shown in the allocation of time to teach the subject. It is very disturbing to learn that this subject is sacrificed a lot to benefit other priority subjects in the FET curriculum. It should always be remembered that this subject was introduced for the purpose of a holistic development of the learners. With the identified academic value of the subject, L.O., it is without doubt that the subject is indispensable within the FET curriculum.

A dissertation submitted to the Faculty Of Education in fulfillment of the requirements for the Degree Of Master Of Education in the Department Of Foundations of Education at the University Of Zululand, 2018 / Principals are facing challenges in managing the teaching of Agricultural Sciences in the FET band, and this leads to some schools phasing out Agricultural Sciences. The aim of this study was to investigate the factors contributing to challenges principals experience in managing the teaching Agricultural Sciences in the FET band. The study adopted mixed methods approach and used quantitative and qualitative methods. Questionnaires were used to collect quantitative data and were completed by forty teachers. An interview schedule was employed to collect qualitative data, and ten principals were interviewed. Simple random sampling was used to select participants for quantitative data and purposive sampling was employed in the selection of participants for qualitative data. Quantitative data was analyzed through the Statistical Package for Social Science (SPSS) version 24 while qualitative data was analyzed thematically. The study revealed that principals lack managerial skills in the teaching of Agricultural Sciences. It was recommended that principals should be capacitated in managerial skills of teaching the subject, and this should be a continuous process because of the constant curriculum changes. / National Research Foundation of South Africa (Grant Number:CPT160513164973 and 105246)

A dissertation submitted to the Faculty of Education in fulfillment of the requirements for the Degree of Masters in Education in the Department of Curriculum and Instructional Studies at the University of Zululand, 2018 / This study aimed at determining the role that Life Orientation teachers (LO) play in preparing Further Education and Training (FET) phase learners for Post schooling education (PSE) in Bhekuzulu circuit, Zululand District. The objectives of the study were to (a) establish the role that LO teachers play in preparing FET phase learners for post schooling education in Bhekuzulu circuit, (b) find out whether there are support programmes available to enable LO teachers support their learners for their post schooling education, (c) establish the type of challenges that LO teachers face which hinder them from supporting and preparing FET learners for post schooling education. A mixed-methods research approach was used in a case study constituted of 70 participants. To this end, the questionnaire and focus group interviews (FGIs) were used to collect data. A qualitative thematic content analysis was used to analyse data, by grouping similar themes. Furthermore, a quantitative data analysis was used to quantify the phenomenon by analysing patterns and trends of the respondents. The findings reveal that teachers do support FET learners in preparation for PSE with the little skills and knowledge they possess. However, the major challenge that prevailed in this study is that LO teachers are not trained to provide CG; most of these teachers do not have specialisation in teaching LO and/or CG. Other challenges that prevailed were the insufficient time allocated to teach LO, lack of CG resources, negative attitudes towards LO as subjects by teachers as well as school management teams. Moreover, the study found a lack of CG programmes in schools and poor implementation of these programmes, poor subjects groupings offered in schools, poor learners’ efficacy in career choices and lack of community support. The study recommends that the Provincial Department of Basic Education should train all LO teachers using accredited service providers to enable teachers to provide CG to learners in a meaningful way. Secondly, more time should be allocated to LO especially in the teaching of careers and career choices. Lastly, schools should be provided with common basic CG programmes to be implemented by all schools and be monitored intensively by the CG officials. / National Research Foundation Of South Africa (Grant Number:CP160513164973 and 105246)