<p> Tantalum thin film resistors have been reactively sputtered in oxygen and nitrogen simultaneously. The films studied had resistivities ranging from 400μΩ-cm to 3 x 10^4 μΩ-cm. The corresponding TCR values ranged from -50 ppm/°C to -2,000 ppm/°C. Conductance-temperature measurements show that electrical conduction in discontinuous films of metallic islands (typically 100 A°) largely surrounded by regions of Ta2O5 (typically 50 A°) may be due to a tunneling mechanism of negative TCR operating concurrently with a metallic mechanism of positive TCR via interconnected metallic islands.</p> <p> Irradiation of these discontinuous films by 150 keV protons produces a conductance increase which is attributed to an enhanced tunneling mechanism via electronic defect levels in the inter-island oxide regions. During irradiation of these films at 30°K, the conductance change increases and approaches apparent saturation. This nonlinearity is attributed to a combination of spontaneous recombination and close-pair thermal annealing. The number of unstable sites surrounding each defect is found to be ≥ 4. Thermal recovery of the conductance proceeds in two main stages: Stage A (34°K to 150°K) is attributed to close-pair or correlated recombination; Stage B (150°K to 300°K) is attributed to uncorrelated migration of defects to gap-island interfaces, as is indicated by the greatly reduced Stage B annealing which is observed for continuous, polycrystalline films of Ta2O5, having a typical grain size of 1,500 A°. Negative annealing stages (characterized by a conductance increase) indicate a metallic conduction process via connected metallic islands.</p> <p> For 286°K irradiation of discontinuous films, the conductance initially increases with fluence in a nonlinear fashion until a threshold fluence is reached, at which point the conductance decreases with fluence. The nonlinearity of the conductance increase is attributed to trapping of mobile radiation-produced defects at gap-island interfaces during irradiation. The subsequent conductance decrease is attributed to a shift in the Fermi level, and thus the height of the tunneling barrier, as the result of the formation of unequal concentrations of stable radiation-produced donor and aeceptor defects since unequal concentrations of these defects can be expected to annihilate at the gap-island interface. The absence of this conductance decrease in continuous polycrystalline films is consistent with this model, since the absence of gap-island interfaces is expected to result in equal concentrations of stable donor and acceptor levels being produced.</p> <p> The observed negative increase in TCR with fluence is attributed to an increase in the proportion of the tunneling mechanism of negative TCR (as the result of radiation-produced defects in the inter-island oxide regions) relative to the proportion of the metallic conduction mechanism of positive TCR. The difference between the TCR recovery after irradiation at 30°K (little recovery between 150°K and 300°K) and the conductance recovery (about 50 percent of the recovery occurs between 150°K and 300°K) is attributed to the expected greater influence of metallic recovery on the annealing of the film TCR relative to the annealing of the film conductance.</p> / Thesis / Doctor of Philosophy (PhD)

The backprojection-then-filtering algorithm was applied to proton CT data to reconstruct a map of proton stopping power relative to water (RSP) in air, water and bone. Backprojections were performed along three commonly used path estimates for the proton: straight line path, cubic spline path, and most likely path. The proton CT data was obtained through simulations using the GEANT4 simulation toolkit. Two elliptical phantoms were inspected, and an accuracy of 0.2% and 0.8% was obtained for the RSP in water and bone respectively in the region of interest, while the RSP of air was significantly underestimated.

Frente à crescente necessidade de que novas tecnologias sejam capazes de operar com confiabilidade em ambientes hostis, a análise dos efeitos da radiação ionizante em dispositivos semicondutores se tornou um ramo de pesquisa em contínua ascensão, contribuindo para o desenvolvimento de tecnologias estratégicas e promovendo o aprimoramento científico e o desenvolvimento tecnológico da humanidade. Por outro lado, a atual tecnologia CMOS de fabricação de circuitos integrados apresenta sinais de limitação, em grande parte, devido às características físicas inerentes ao seu princípio de funcionamento, sendo necessário, portanto, que dispositivos com novos mecanismos de operação e geometrias sejam desenvolvidos. Dentre eles, transistores de tunelamento induzido por efeito de campo (TFET) se destacam por apresentarem menor corrente de dreno quando desligados e a possibilidade de se atingir inclinações de sublimiar abaixo do limite teórico estabelecido por dispositivos MOSFET de 60 mV/déc à temperatura ambiente, permitindo-se a redução da tensão de alimentação dos transistores para cerca de 0,5 V. Buscando contribuir com as necessidades destas duas áreas de pesquisa, neste projeto de mestrado, foi analisado o comportamento de TFETs de silício com porta tripla, fabricados sobre lâmina SOI (silício sobre isolante), submetidos a até 10 Mrad(Si) de dose acumulada total enquanto não polarizados, gerada por uma fonte de prótons de 600 keV de energia. Em uma análise inicial, após exposição de dispositivos de 1 µm de largura de aleta a uma dose de 1 Mrad(Si), foi possível observar uma redução no nível corrente de dreno de estado ligado do dispositivo (ION ? 300 pA) de até 10%, não associada à uma alteração da corrente de porta. Além disso, o efeito da radiação nesses transistores reduz de 10% para 2% quando se aumenta o comprimento do canal de 150 nm para 1 µm. As razões para ambos os fenômenos foram discutidas com base na competição entre os efeitos de divisão da corrente de dreno na primeira e segunda interfaces e do aumento da resistência de canal em dispositivos mais longos. Para uma análise em função da dose acumulada total, dispositivos SOI TFET e SOI MOSFET, ambos de porta tripla, foram caracterizados eletricamente 14 dias após cada etapa de irradiação. De maneira geral, dispositivos de ambas as tecnologias, com largura de aleta igual a 40 nm, apresentaram baixa susceptibilidade aos efeitos cumulativos da radiação ionizante. No entanto, quando considerados dispositivos com largura de aleta muito maior que a altura da aleta (WFIN = 1 µm), nos quais a influência das portas laterais sobre o acoplamento eletrostático do canal é praticamente inexistente, transistores túnel-FET se destacaram positivamente. Esses dispositivos se mostraram resistentes aos efeitos de dose ionizante total (TID) mesmo para doses de 5 Mrad(Si), enquanto os transistores SOI MOSFET apresentaram uma variação gradual de seus parâmetros a cada dose acumulada. Um exemplo disso é a variação observada na inclinação de sublimiar, de 32,5% nos transistores SOI MOSFET e 5,6% nos transistores SOI TFET. Somente após 10 Mrad(Si) de irradiação por prótons é que os TFETs de aleta larga apresentaram variações mais significativas em sua curva de transferência (ID x VG). Tanto para a configuração como tipo P quanto para a configuração como tipo N, notou-se um deslocamento de até 80 mV da curva de transferência do dispositivo para a esquerda, provocado, segundo análise via simulações, pelas cargas fixas positivas geradas pela irradiação no óxido enterrado do dispositivo. Adicionalmente, foi possível observar um aumento da corrente de tunelamento assistido por armadilhas (TAT) nesses dispositivos, provocada pelo aumento da densidade de estados de interface causada também pelos efeitos de TID. O aumento de TAT foi reconhecido como o principal responsável pela degradação de 23,3% da inclinação de sublimiar dos TFETs, com WFIN igual 1 µm, após 10 Mrad(Si). Apesar das mudanças observadas, foi possível se sugerir, através da comparação com transistores SOI MOSFET de dimensões equivalentes, que transistores de tunelamento induzido por efeito de campo podem, futuramente, se tornar referência no quesito imunidade aos efeitos de dose ionizante total. / In light of the increasing need for new technologies to be able to operate reliably in harsh environments, the analysis of the effects of ionizing radiation on semiconductor devices has become a continually rising field of research, contributing to the development of strategic technologies and promoting scientific improvement and technological development of humankind. On the other hand, the current CMOS technology for the manufacture of integrated circuits shows signs of limitation, mostly, due to the physical characteristics inherent to its operating principle, thus, it is necessary that devices with new operating mechanisms and geometries be developed. Among them, tunnel field-effect transistors (TFET) stand out because of its lower OFF state current and the possibility of reaching subthreshold swing below the theoretical limit established by MOSFET devices of 60 mV/dec at room temperature, allowing to reduce transistors supply voltage to about 0.5 V. In order to contribute with both areas, the behavior of silicon based triple gate TFETs fabricated on a SOI (silicon-on-insulator) substrate and exposed to a total cumulative dose of 10 Mrad (Si) (while not biased) generated by a 600 keV proton beam was analyzed. In an initial analysis after exposure of 1 µm width devices to 1 Mrad(Si), it was possible to observe an ON state current reduction (ION ? 300 pA) up to 10%, not associated to a gate current change. Beyond that, irradiation effects on these devices reduce from 10% to 2% with the channel length increasing from 150 nm to 1 µm. The reasons behind these phenomena were discussed based on the competition between a high channel resistance present in longer devices and the TFET drain current reduction due to the irradiation. For a total cumulative dose analysis, triple gate SOI TFET and triple gate SOI MOSFET devices were characterized 14 days after each irradiation phase. In general, devices of both technologies, with 40 nm fin width, presented low susceptibility to the cumulative effects of ionizing radiation. However, for devices with fin width larger than fin height (WFIN = 1 µm) in which the influence of side gates on the electrostatic coupling of the channel is weak, tunnel-FET transistors have stood out. These devices were resistant to the effects of total ionizing dose (TID) even for doses as high as 5 Mrad(Si), while SOI MOSFET transistors showed a gradual variation of their parameters at each accumulated dose. The variation observed for the subthreshold swing, for example, was about 32.5% for SOI MOSFET devices and 5.6% for SOI TFET devices. TFETs with wider fin have shown significant variations on its transfer characteristic (ID x VG) only after 10 Mrad(Si) of proton irradiation. For both P-type and N-type configurations, it was observed a shift of the transfer curve to the left up to 80 mV caused by, according to simulations, the positive fixed charges generated in the buried oxide by irradiation. In addition, it was possible to observe a trap assisted tunneling (TAT) current increase caused by interface states promoted by TID effects. The increase of TAT was recognized as the main responsible for the degradation of 23.3% of the subthreshold swing of the TFETs after 10 Mrad(Si). In spite of the observed changes, it was possible to suggest, through comparison with SOI MOSFET devices of equivalent dimensions, which tunnel field-effect transistors may become a reference when considering immunity against total ionizing dose effects.

Frente à crescente necessidade de que novas tecnologias sejam capazes de operar com confiabilidade em ambientes hostis, a análise dos efeitos da radiação ionizante em dispositivos semicondutores se tornou um ramo de pesquisa em contínua ascensão, contribuindo para o desenvolvimento de tecnologias estratégicas e promovendo o aprimoramento científico e o desenvolvimento tecnológico da humanidade. Por outro lado, a atual tecnologia CMOS de fabricação de circuitos integrados apresenta sinais de limitação, em grande parte, devido às características físicas inerentes ao seu princípio de funcionamento, sendo necessário, portanto, que dispositivos com novos mecanismos de operação e geometrias sejam desenvolvidos. Dentre eles, transistores de tunelamento induzido por efeito de campo (TFET) se destacam por apresentarem menor corrente de dreno quando desligados e a possibilidade de se atingir inclinações de sublimiar abaixo do limite teórico estabelecido por dispositivos MOSFET de 60 mV/déc à temperatura ambiente, permitindo-se a redução da tensão de alimentação dos transistores para cerca de 0,5 V. Buscando contribuir com as necessidades destas duas áreas de pesquisa, neste projeto de mestrado, foi analisado o comportamento de TFETs de silício com porta tripla, fabricados sobre lâmina SOI (silício sobre isolante), submetidos a até 10 Mrad(Si) de dose acumulada total enquanto não polarizados, gerada por uma fonte de prótons de 600 keV de energia. Em uma análise inicial, após exposição de dispositivos de 1 µm de largura de aleta a uma dose de 1 Mrad(Si), foi possível observar uma redução no nível corrente de dreno de estado ligado do dispositivo (ION ? 300 pA) de até 10%, não associada à uma alteração da corrente de porta. Além disso, o efeito da radiação nesses transistores reduz de 10% para 2% quando se aumenta o comprimento do canal de 150 nm para 1 µm. As razões para ambos os fenômenos foram discutidas com base na competição entre os efeitos de divisão da corrente de dreno na primeira e segunda interfaces e do aumento da resistência de canal em dispositivos mais longos. Para uma análise em função da dose acumulada total, dispositivos SOI TFET e SOI MOSFET, ambos de porta tripla, foram caracterizados eletricamente 14 dias após cada etapa de irradiação. De maneira geral, dispositivos de ambas as tecnologias, com largura de aleta igual a 40 nm, apresentaram baixa susceptibilidade aos efeitos cumulativos da radiação ionizante. No entanto, quando considerados dispositivos com largura de aleta muito maior que a altura da aleta (WFIN = 1 µm), nos quais a influência das portas laterais sobre o acoplamento eletrostático do canal é praticamente inexistente, transistores túnel-FET se destacaram positivamente. Esses dispositivos se mostraram resistentes aos efeitos de dose ionizante total (TID) mesmo para doses de 5 Mrad(Si), enquanto os transistores SOI MOSFET apresentaram uma variação gradual de seus parâmetros a cada dose acumulada. Um exemplo disso é a variação observada na inclinação de sublimiar, de 32,5% nos transistores SOI MOSFET e 5,6% nos transistores SOI TFET. Somente após 10 Mrad(Si) de irradiação por prótons é que os TFETs de aleta larga apresentaram variações mais significativas em sua curva de transferência (ID x VG). Tanto para a configuração como tipo P quanto para a configuração como tipo N, notou-se um deslocamento de até 80 mV da curva de transferência do dispositivo para a esquerda, provocado, segundo análise via simulações, pelas cargas fixas positivas geradas pela irradiação no óxido enterrado do dispositivo. Adicionalmente, foi possível observar um aumento da corrente de tunelamento assistido por armadilhas (TAT) nesses dispositivos, provocada pelo aumento da densidade de estados de interface causada também pelos efeitos de TID. O aumento de TAT foi reconhecido como o principal responsável pela degradação de 23,3% da inclinação de sublimiar dos TFETs, com WFIN igual 1 µm, após 10 Mrad(Si). Apesar das mudanças observadas, foi possível se sugerir, através da comparação com transistores SOI MOSFET de dimensões equivalentes, que transistores de tunelamento induzido por efeito de campo podem, futuramente, se tornar referência no quesito imunidade aos efeitos de dose ionizante total. / In light of the increasing need for new technologies to be able to operate reliably in harsh environments, the analysis of the effects of ionizing radiation on semiconductor devices has become a continually rising field of research, contributing to the development of strategic technologies and promoting scientific improvement and technological development of humankind. On the other hand, the current CMOS technology for the manufacture of integrated circuits shows signs of limitation, mostly, due to the physical characteristics inherent to its operating principle, thus, it is necessary that devices with new operating mechanisms and geometries be developed. Among them, tunnel field-effect transistors (TFET) stand out because of its lower OFF state current and the possibility of reaching subthreshold swing below the theoretical limit established by MOSFET devices of 60 mV/dec at room temperature, allowing to reduce transistors supply voltage to about 0.5 V. In order to contribute with both areas, the behavior of silicon based triple gate TFETs fabricated on a SOI (silicon-on-insulator) substrate and exposed to a total cumulative dose of 10 Mrad (Si) (while not biased) generated by a 600 keV proton beam was analyzed. In an initial analysis after exposure of 1 µm width devices to 1 Mrad(Si), it was possible to observe an ON state current reduction (ION ? 300 pA) up to 10%, not associated to a gate current change. Beyond that, irradiation effects on these devices reduce from 10% to 2% with the channel length increasing from 150 nm to 1 µm. The reasons behind these phenomena were discussed based on the competition between a high channel resistance present in longer devices and the TFET drain current reduction due to the irradiation. For a total cumulative dose analysis, triple gate SOI TFET and triple gate SOI MOSFET devices were characterized 14 days after each irradiation phase. In general, devices of both technologies, with 40 nm fin width, presented low susceptibility to the cumulative effects of ionizing radiation. However, for devices with fin width larger than fin height (WFIN = 1 µm) in which the influence of side gates on the electrostatic coupling of the channel is weak, tunnel-FET transistors have stood out. These devices were resistant to the effects of total ionizing dose (TID) even for doses as high as 5 Mrad(Si), while SOI MOSFET transistors showed a gradual variation of their parameters at each accumulated dose. The variation observed for the subthreshold swing, for example, was about 32.5% for SOI MOSFET devices and 5.6% for SOI TFET devices. TFETs with wider fin have shown significant variations on its transfer characteristic (ID x VG) only after 10 Mrad(Si) of proton irradiation. For both P-type and N-type configurations, it was observed a shift of the transfer curve to the left up to 80 mV caused by, according to simulations, the positive fixed charges generated in the buried oxide by irradiation. In addition, it was possible to observe a trap assisted tunneling (TAT) current increase caused by interface states promoted by TID effects. The increase of TAT was recognized as the main responsible for the degradation of 23.3% of the subthreshold swing of the TFETs after 10 Mrad(Si). In spite of the observed changes, it was possible to suggest, through comparison with SOI MOSFET devices of equivalent dimensions, which tunnel field-effect transistors may become a reference when considering immunity against total ionizing dose effects.

Bakgrund: Varje år insjuknar 300 barn i cancer varav cirka 30% av dessa diagnostiseras med hjärntumör. Protonstrålning har sedan 2015 varit ett bra behandlingsalternativ för att minska seneffekterna av strålningen. I dagsläget görs all protonstrålning i Uppsala. Barn med cancer vill vara delaktiga i sin vård och behandling och ålderanpassad information är då viktigt. Syfte: Att beskriva barnsjuksköterskans erfarenhet av att förbereda barn med hjärntumör inför protonstrålning på annan ort. Metod: Sju stycken kvalitativa intervjuer genomfördes med sjuksköterskor. Insamlat material analyserades med kvalitativ innehållsanalys (Elo och Kyngäs 2008). Resultat: Resultatet presenterar tre kategorier: Att nå barnet beskriver vikten av att ha barnet i fokus och anpassa informationen utifrån individen. Att möta utmaningar belyser tidens betydelse för hur förberedelserna blir, att det upplevdes som svårare att förbereda barn när det utförs på annan ort. Att inge trygghet beskriver sjuksköterskans roll att vara en trygg punkt för familjen samt att se till hela familjen. Konklusion: Konklusionen av studien är att barnsjuksköterskorna är medvetna om vikten av att göra barn delaktiga i förberedelser för att främja hälsa samt att tidens påverkan spelar in när sjuksköterskan ska förbereda och nå fram till barnet. / Background: Every year, 300 children are diagnosed with cancer, of which about 30% are diagnosed with brain tumor. Proton radiation therapy has been a good treatment alternative since 2015 to reduce the late effects of radiation. At the moment, all proton radiation therapy in Sweden is carried out in Uppsala. Children with cancer want to participate in their care and treatment and age-appropriate information is therefore important. Purpose: To describe the pediatric nurse's experience in preparing children with brain tumors for proton radiation therapy in another location. Method: Seven qualitative interviews were conducted with nurses. Collected material was analyzed with qualitative content analysis (Elo &amp; Kyngäs, 2008). Result: The result presents three categories: Reaching the child describes the importance of having the child in focus and adapting the information based on the individual. Facing challenges highlights the importance of time and how it affects the preparations, it was perceived as more difficult to prepare children getting treatment in another location. Providing security describes the nurse's role to be a safe point for the family and to look after the whole family. Conclusion: The conclusion of the study is that the pediatric nurses are aware of the importance of children’s’ participation in their preparation, to promote health and that time plays an influential role in the preparation and the nurse’s ability to connect with the children.

The boundaries of human space exploration continue to expand with new technology and discoveries making it even more important to investigate the effects of space on biological systems. Although humans have explored space in small increments, reproductive studies must be conducted to determine if stable short- or long-term residences for humans can exist in space. This study explored the effects of whole-body proton radiation on uterine smooth muscle known as the myometrium. Two types of mice utilized in this study were C57BL/6 and B6.129S6Cybbtm1Din/J NOX2 knockout mice. C57BL/6 mice are standard laboratory mice that were used to represent the wildtype treatment group (N=18). The B6.129S6Cybbtm1Din/J NOX2 knockout mice have the NADPH Oxidase 2 gene shut off and represented the NOX2 Knockout treatment group (N=18). A third treatment group was made up of half of the C57BL/6 mice and were fed apocynin (N=18). Apocynin has been shown to inhibit NAPDH oxidase production in mice. NADPH Oxidase 2 is involved in the production of deleterious Reactive Oxygen Species (ROS); thus, apocynin should reduce the production of ROS in mice exposed to radiation. Different doses of radiation (0Gy, 0.5Gy, and 2.0Gy) were applied to the myometrium creating three different treatment subgroups within each mouse strain. The mice received 250 MeV protons at an approximate dose rate of 70cGy/ minute. Myometrium tissue was obtained one week following the radiation treatment. The uteri were removed, embedded, sectioned, and stained in hematoxylin and eosin solution. Thickness was determined by taking five measurements each of the outer longitudinal layer length, the inner circular layer length and the total length of both layers of the myometrium for three individual pieces of tissue for each animal. A one-way analysis of variance (ANOVA) was used to determine statistical differences between the groups and subgroups. Wildtype control mice exposed to 2.0Gy (N=5) of radiation had the thickest outer longitudinal layers compared to wildtype mice exposed to 0Gy (N=5) and 0.5Gy (N=6) (p=0.005, p=0). In the apocynin fed and Knockout treatment groups, the subgroups exposed to 0Gy had the thickest layers compared to their respective subgroups exposed to 0.5Gy and 2.0Gy. The apocynin fed mice exposed to 0Gy (N=6) outer longitudinal layer was statistically significantly thicker than the apocynin-fed mice exposed to 0.5Gy (p=0.004; N=6). The inner circular layer of the apocynin-fed mice exposed to 0.5Gy was statistically significantly thicker than the apocynin-fed mice exposed to 2.0Gy (p=0.001; N=6). Amongst the treatment groups, the wildtype control versus the apocynin fed mice exposed to 0Gy showed the apocynin-fed group to have the thicker outer longitudinal layer (p=0.003) and combined layers (p=0.001). Overall, the knockout group showed no statistical difference when compared to the wildtype control group. Further studies are necessary to reduce the possible confounding effect of the estrous cycle in the mice. The different phases of the mice estrus cycle may inadvertently affect the mouse uterine thickness due to the fluctuations in hormones. This study will add to the limited research regarding the female reproductive system in hopes of expanding the knowledge needed to actualize space colonization.

GaN-HEMTs (Gallium Nitride-based High Electron Mobility Transistors) have, thanks to the large band gap of GaN, electrical properties that are suitable for applications of high electrical voltages, high currents, and fast switching. The large band gap also gives GaN-HEMTs a high resistance to radiation. In this degree project, the effects of 2 MeV proton irradiation of GaN-HEMTs constructed on both silicon carbide and silicon substrates are investigated. 20 transistors per substrate were irradiated in the particle accelerator 5 MV NEC Pelletron in the Ångström laboratory at Uppsala University. These transistors were exposed to radiation doses in the range of 10^11 to 10^15 protons/cm^2. The analysis shows that both transistors on silicon, as well as silicon carbide, are unaffected by proton irradiation up to a dose of 10^14 protons/cm^2. GaN-on-Si transistors show less influence of radiation than GaN-on-SiC transistors. The capacitances between gate and drain as well as drain and source for both GaN-on-SiC and GaN-on-Si HEMTs show hysteresis as a function of forward and backward gate voltage sweeps for the radiation dose of 10^15 protons/cm^2. / GaN-HEMTs (Galliumnitridbaserade High Electron Mobility Transistors) har tack vare det stora bandgapet i GaN goda elektriska egenskaper som lämpar sig för höga elektriska spänningar, höga strömmar och snabb växling mellan av- och på-tillstånd. Det stora bandgapet ger även GaN-HEMTs ett stort motstånd mot strålning.I detta examensarbete undersöks effekterna av 2 MeV protonbestrålning av GaN-HEMTs. Dessa HEMTs är konstruerade på både kiselkarbid- och kiselsubstrat.20 transistorer per transistorsubstrat bestrålades i partikelacceleratorn 5 MV NEC Pelletron i Ångströmslaboratoriet vid Uppsala Universitet. Dessa transistorer utsattes för strålningsdoser inom intervallet 10^11 till 10^15 protoner/cm^2. Resultaten visar att både tranisistorer på kisel såsom kiselkarbid är opåverkade av strålning upp till en dos av 10^14 protoner/cm^2. GaN-på-Si-transistorer visar en mindre påverkan av protonstrålning än GaN-på-SiC-transistorer. Ytterligare uppstod hysteresis för kapacitanser mellan gate och drain och mellan gate och source som en funktion av fram- och bakriktad gate-spänning efter en strålningsdos av 10^15 protoner/cm^2.

The objective of this work is to provide a comprehensive analysis of the small-signal and broadband noise performance of highly scaled silicon-based field-effect transistors (FETs), and develop high-frequency noise models for robust radio frequency (RF) circuit design. An analytical RF noise model is developed and implemented for scaled Si-CMOS devices, using a direct extraction procedure based on the linear two-port noise theory. This research also focuses on investigating the applicability of modern CMOS technologies for extreme environment electronics. A thorough analysis of the DC, small-signal AC, and broadband noise performance of 0.18 um and 130 nm Si-CMOS devices operating at cryogenic temperatures is presented. The room temperature RF noise model is extended to model the high-frequency noise performance of scaled MOSFETs at temperatures down to 77 K and 10 K. Significant performance enhancement at cryogenic temperatures is demonstrated, indicating the suitability of scaled CMOS technologies for low temperature electronics. The hot-carrier reliability of MOSFETs at cryogenic temperatures is investigated and the worst-case gate voltage stress condition is determined. The degradation due to hot-carrier-induced interface-state creation is identified as the dominant degradation mechanism at room temperature down to 77 K. The effect of high-energy proton radiation on the DC, AC, and RF noise performance of 130 nm CMOS devices is studied. The performance degradation is investigated up to an equivalent total dose of 1 Mrad, which represents the worst case condition for many earth-orbiting and planetary missions. The geometric scaling of MOSFETs has been augmented by the introduction of novel FET designs, such as the Si/SiGe MODFETs. A comprehensive characterization and modeling of the small-signal and high-frequency noise performance of highly scaled Si/SiGe n-MODFETs is presented. The effect of gate shot noise is incorporated in the broadband noise model. SiGe MODFETs offer the potential for high-speed and low-voltage operation at high frequencies and hence are attractive devices for future RF and mixed-signal applications. This work advances the state-of-the-art in the understanding and analysis of the RF performance of highly scaled Si-CMOS devices as well as emerging technologies, such as Si/SiGe MODFETs. The key contribution of this dissertation is to provide a robust framework for the systematic characterization, analysis and modeling of the small-signal and RF noise performance of scaled Si-MOSFETs and Si/SiGe MODFETs both for mainstream and extreme-environment applications.