A strategy is presented for modeling of performance variation in polycrystalline thin film transistors (TFTs) due to grain size variation. A Poisson area scatter is used to model the number of grains ...in a TFT, which is converted to grain size and substituted into physically based models for threshold and mobility. An increase in device variation is predicted as the device and grain sizes converge through scaling or process changes. Comparison of the model with measurements of NMOS TFTs results in reasonable agreement.
A 2 GHz acoustic phase measurement system has been developed and used for in-situ monitoring of thin film thickness and temperature in silicon wafer processing. Initial evaporation experiments in a ...vacuum station have shown a film thickness resolution of approximately 1000 AA with a potential resolution to approximately 1 AA. The potential of this system for making temperature measurements has also been explored, and initial experiments in an oven have shown a temperature resolution of 0.01 K.< >
Temperature measurements of silicon wafers in semiconductor processing conditions using acoustic techniques are being investigated. Theoretical models for the temperature dependence of zeroth-order ...Lamb waves have been developed. Initial experimental data for zeroth-order antisymmetric Lamb waves and acoustic waves through a layer of ambient above the silicon wafer have been obtained. The temperature measurement of the layer of ambient is expected to have sensitivities better than +or-1 degrees C, and it is expected that this measurement will yield the temperature of the bulk of the wafer as well.< >
Indian society includes a large number of first-generation learners, especially from the poor & disadvantaged parts of the population. Research on this group is briefly reviewed. Characteristics of ...first-generation learners in Ru, semi-Ru, & Ur areas (N = 31, 86, & 83 pupils, respectively) are compared. Ru Ss tend to be older, but are roughly on a level with semi-Ru & Ur Ss in cognitive development; the latter two groups display few differences. 5 Tables, 13 References. W. H. Stoddard
Objective
To evaluate the long‐term risk of further gynaecological surgery and cancer in women with endometriosis.
Design
Cohort study.
Setting
Scotland.
Participants
281 937 women with nearly ...5 million person years (4 923 628) of follow up from 1981 to 2010.
Methods
In this national population‐based study we compared 17 834 women with a new surgical diagnosis of endometriosis with 83 303 women with no evidence of endometriosis at laparoscopy, 162 966 women who underwent laparoscopic sterilisation, and 17 834 age‐matched women from the general population. Cox proportional hazards regression was used to calculate crude and adjusted hazard ratios with 95% confidence intervals.
Main outcome measures
Risk of further gynaecological surgery, number and type of repeat surgery and time to repeat surgery from the diagnosis of endometriosis. Cancer outcomes included subsequent risk of all cancer, gynaecological and non–gynaecological cancers.
Results
Women with endometriosis had a significantly higher risk of further surgery when compared with women with no evidence of endometriosis at laparoscopy hazard ratio (HR) 1.69, 95% (confidence interval) CI 1.65–1.73, women who had undergone laparoscopic sterilisation (HR 3.30, 95% CI 3.23–3.37) and age‐matched women from the general population (HR 5.95, 95% CI 5.71–6.20). They also have an increased risk of ovarian cancer when compared with general population counterparts (HR 1.77, 95% CI 1.08–2.89) or those with laparoscopic sterilisation (HR 1.75, 95% CI 1.2–2.45).
Conclusion
Women with surgically diagnosed endometriosis face an increased risk of multiple surgery. They have a higher chance of developing ovarian cancer in comparison with the general population and women with laparoscopic sterilisation.
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Women with endometriosis face an increased risk of recurrent surgery and developing ovarian cancer.
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Women with endometriosis face an increased risk of recurrent surgery and developing ovarian cancer.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Objective
To determine pregnancy outcomes in women with endometriosis.
Design
A national population based cohort study using record linkage.
Setting
Scotland.
Participants
A cohort of 14 655 women ...followed up over a 30‐year period (1981–2010).
Methods
In a nationwide Scottish study, we compared pregnancy outcomes in 5375 women with surgically confirmed endometriosis with outcomes in 8710 women without endometriosis who were pregnant during the same time period. Data were analysed using univariable and multivariable logistic regression after adjusting for confounding factors.
Main outcome measures
Outcome measures evaluated included miscarriage, ectopic pregnancy, stillbirths and other pregnancy complications such as hypertensive disorders of pregnancy, antepartum and postpartum haemorrhage, operative delivery and preterm births. The outcomes were presented as adjusted odds ratios (OR) with 95% confidence intervals (CI).
Results
On multivariable analysis, after adjusting for age, parity, socio‐economic status and year of delivery, women with endometriosis when compared to women without endometriosis, had a significantly higher risk of early pregnancy complications with adjusted OR (95% CI) of 1.76 (1.44, 2.15) and 2.70 (1.09, 6.72) for miscarriage and ectopic pregnancy, respectively. A previous diagnosis of endometriosis was associated with a significantly increased risk of adjusted OR (95% CI) placenta praevia 2.24 (1.52, 3.31), unexplained antepartum haemorrhage 1.67 (1.39, 2.00), postpartum haemorrhage 1.30 (1.61, 1.46) and preterm births 1.26 (1.07, 1.49) in pregnancies progressing beyond 24 weeks.
Conclusion
Endometriosis predisposes women to an increased risk of early pregnancy loss and later pregnancy complications.
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Endometriosis predisposes women to an increased risk of early pregnancy loss and later pregnancy complications.
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Endometriosis predisposes women to an increased risk of early pregnancy loss and later pregnancy complications.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
This paper presents a unified approach for the accurate extraction of specific contact resistivity (ρ c ) for ohmic contacts. Using 2-D simulations, which account for the current flow, or crowding ...around the contact window, we have analysed the resistance data obtained from the Cross Bridge Kelvin Resistor, the Contact End Resistor, and the Transmission Line Tap Resistor. For each particular structure, a universal set of curves is derived that allows accurate determination of ρ c , given the geometry of the structure. The values obtained for ρ c are independant of the test structure type, its geometry and the contact area. The data suggests that in the past researchers have overestimated ρ c , and that contact resistance will not limit device performance even with submicron design rules.
A major limitation for future scaling of CMOS is the rapidly increasing contact resistance 1. An improved understanding of the behavior of the submicron contacts that will be used by the next decade ...requires experimental data and useful theoretical models. No experimental data are available in the literature to date for the resistance of sub-halfmicron contacts. This paper reports new findings on contacts of Al, TiN, PtSi, and CVD W to Si with sizes as small as 0.25 gm. The measured resistance values are compared to that obtained using a 2-D model and the discrepencies are discussed.
Degradation in ultrathin dielectric films due to high-field stress is a critical concern in ULSI technology. We investigate here the link between trap-generation and breakdown as a function of five ...technologically relevant parameters, namely stress-current density (10/sup -3/-10/sup 1/ A/cm/sup 2/), oxide thickness (70-250 A), stress temperature (25-100 /spl deg/C), charge-injection polarity (gate vs substrate), and nitridation of pure oxide (using N/sub 2/O). For all five parameters, a strong correlation has been observed between oxide degradation and the generation of new traps by physical bondbreaking.< >
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