TEM Direct Observation of Gate Oxide Defects

Author(s):  
Nathan Wang ◽  
Sabbas Daniel

Abstract This paper describes the FA technique to identify very tiny defects that cause gate oxide damage. These defects as examples include crystal originated pits, gate oxide pinhole and residual. The defects may have the same electrical signature; the same kind of in gate oxide will be seen when the sample is simply deprocessed with wet chemical and observed with SEM; but they are distinctly different mechanisms. Electrical test, emission microscope, FIB and SEM were used to localize the defect and TEM for the final analysis. The application of planeview, cross-sectional and three-dimensional TEM is discussed.

1987 ◽  
Vol 107 ◽  
Author(s):  
Kyung-Ho Park ◽  
T. Sasaki ◽  
T. Iwai ◽  
M. Hasegawa ◽  
N. Sasaki

AbstractThis paper describes cross-sectional transmission electron microscopy (TEM) observation on finished 3-D MOS devices, fabricated with a laser-recrystallized SOI. The laser-recrystallized SOI contained crystal defects such as micro-twinning, grain boundaries and dislocations. It is also clearly shown that the interface roughness between the gate oxide and SOI is as much as 20 nm height, in where the interface is very smooth between the gate oxide and bulk silicon.


Author(s):  
N. Ohtani ◽  
T. Katayama ◽  
H. Yamamoto ◽  
H. Koyama

Abstract A new technique to detect gate oxide defects has been developed. This method is based on electrochemical wet (ECW) etching of Si in KOH:H 20 electrolyte. Using this method, only leaky poly-Si gates caused by gate oxide defects can be clearly observed. When applying a certain voltage to a Si substrate in KOH:H20 after exposing the polySi gates, normal poly-Si gates can be etched, but poly-Si gates shorted to the Si substrate through gate oxide defects remain unetched because of the anodic oxide which covers the leaky gate. This method has proved to be very effective in obtaining information concerning gate oxide integrity without direct observation of gate oxides, which requires complicated deprocessing and a lot of time. This technique also reveals electrical characteristics of gate oxides which may be difficult to identify by conventional physical analysis.


Author(s):  
J.L. Williams ◽  
K. Heathcote ◽  
E.J. Greer

High Voltage Electron Microscope already offers exciting experimental possibilities to Biologists and Materials Scientists because the increased specimen thickness allows direct observation of three dimensional structure and dynamic experiments on effectively bulk specimens. This microscope is designed to give maximum accessibility and space in the specimen region for the special stages which are required. At the same time it provides an ease of operation similar to a conventional instrument.


1997 ◽  
Vol 473 ◽  
Author(s):  
Heng-Chih Lin ◽  
Edwin C. Kan ◽  
Toshiaki Yamanaka ◽  
Simon J. Fang ◽  
Kwame N. Eason ◽  
...  

ABSTRACTFor future CMOS GSI technology, Si/SiO2 interface micro-roughness becomes a non-negligible problem. Interface roughness causes fluctuations of the surface normal electric field, which, in turn, change the gate oxide Fowler-Nordheim tunneling behavior. In this research, we used a simple two-spheres model and a three-dimensional Laplace solver to simulate the electric field and the tunneling current in the oxide region. Our results show that both quantities are strong functions of roughness spatial wavelength, associated amplitude, and oxide thickness. We found that RMS roughness itself cannot fully characterize surface roughness and that roughness has a larger effect for thicker oxide in terms of surface electric field and tunneling behavior.


2018 ◽  
Vol 68 (12) ◽  
pp. 2987-2991
Author(s):  
Cristina Iordache ◽  
Bogdan Vascu ◽  
Eugen Ancuta ◽  
Rodica Chirieac ◽  
Cristina Pomirleanu ◽  
...  

Temporomandibular joint (TMJ) is commonly involved in various immune-mediated rheumatic disorders accounting for significant disability and impaired quality of life. The aim of our study was to assess inflammatory and immune parameters in patients with TMJ arthritis related to rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) and to identify potential relation with severity and dysfunction of TMJ pathology. We performed a cross-sectional study in a cohort of 433 consecutive RA, 32 JIA, 258 AS, and 103 PsA. Only patients presenting with clinically significant TMJ involvement (273) related to their rheumatic condition were included in the final analysis. TMJ involvement is traditionally described in chronic inflammatory rheumatic disorders, particularly in patients with higher levels of inflammation as detected in rheumatoid arthritis and psoriatic arthritis. Disease activity and severity, as well as biological and positive serological assessments (rheumatoid factor, anti-cyclic citrullinated peptide, IL-1) remain significant determinants of the severity of TMJ arthritis.


Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 757
Author(s):  
Maged Sultan Alhammadi ◽  
Abeer Abdulkareem Al-mashraqi ◽  
Rayid Hussain Alnami ◽  
Nawaf Mohammad Ashqar ◽  
Omar Hassan Alamir ◽  
...  

The study sought to assess whether the soft tissue facial profile measurements of direct Cone Beam Computed Tomography (CBCT) and wrapped CBCT images of non-standardized facial photographs are accurate compared to the standardized digital photographs. In this cross-sectional study, 60 patients with an age range of 18–30 years, who were indicated for CBCT, were enrolled. Two facial photographs were taken per patient: standardized and random (non-standardized). The non-standardized ones were wrapped with the CBCT images. The most used soft tissue facial profile landmarks/parameters (linear and angular) were measured on direct soft tissue three-dimensional (3D) images and on the photographs wrapped over the 3D-CBCT images, and then compared to the standardized photographs. The reliability analysis was performed using concordance correlation coefficients (CCC) and depicted graphically using Bland–Altman plots. Most of the linear and angular measurements showed high reliability (0.91 to 0.998). Nevertheless, four soft tissue measurements were unreliable; namely, posterior gonial angle (0.085 and 0.11 for wrapped and direct CBCT soft tissue, respectively), mandibular plane angle (0.006 and 0.0016 for wrapped and direct CBCT soft tissue, respectively), posterior facial height (0.63 and 0.62 for wrapped and direct CBCT soft tissue, respectively) and total soft tissue facial convexity (0.52 for both wrapped and direct CBCT soft tissue, respectively). The soft tissue facial profile measurements from either the direct 3D-CBCT images or the wrapped CBCT images of non-standardized frontal photographs were accurate, and can be used to analyze most of the soft tissue facial profile measurements.


2020 ◽  
Vol 2 (4) ◽  
Author(s):  
Shweta R Singh ◽  
Bunsoth Mao ◽  
Konstantin Evdokimov ◽  
Pisey Tan ◽  
Phana Leab ◽  
...  

Abstract Background The rising incidence of infections caused by MDR organisms (MDROs) poses a significant public health threat. However, little has been reported regarding community MDRO carriage in low- and middle-income countries. Methods We conducted a cross-sectional study in Siem Reap, Cambodia comparing hospital-associated households, in which an index child (age: 2–14 years) had been hospitalized for at least 48 h in the preceding 2–4 weeks, with matched community households on the same street, in which no other child had a recent history of hospitalization. Participants were interviewed using a survey questionnaire and tested for carriage of MRSA, ESBL-producing Enterobacterales (ESBL-E) and carbapenemase-producing Enterobacterales (CPE) by culture followed by antibiotic susceptibility testing. We used logistic regression analysis to analyse associations between collected variables and MDRO carriage. Results Forty-two pairs of households including 376 participants with 376 nasal swabs and 290 stool specimens were included in final analysis. MRSA was isolated from 26 specimens (6.9%). ESBL-producing Escherichia coli was detected in 269 specimens (92.8%) whereas ESBL-producing Klebsiella pneumoniae was isolated from 128 specimens (44.1%), of which 123 (42.4%) were co-colonized with ESBL-producing E. coli. Six (2.1%) specimens tested positive for CPE (4 E. coli and 2 K. pneumoniae). The prevalence ratios for MRSA, ESBL-producing E. coli and ESBL-producing K. pneumoniae carriage did not differ significantly in hospital-associated households and hospitalized children compared with their counterparts. Conclusions The high prevalence of ESBL-E across both household types suggests that MDRO reservoirs are common in the community. Ongoing genomic analyses will help to understand the epidemiology and course of MDRO spread.


Angiology ◽  
2021 ◽  
pp. 000331972110211
Author(s):  
Buyun Jia ◽  
Chongfei Jiang ◽  
Yun Song ◽  
Chenfangyuan Duan ◽  
Lishun Liu ◽  
...  

Increased arterial stiffness is highly prevalent in patients with hypertension and is associated with cardiovascular (CV) risk. Increased white blood cell (WBC) counts may also be an independent risk factor for arterial stiffness and CV events. The aim of the study was to investigate the relationship between differential WBC counts and brachial-ankle pulse wave velocity (baPWV) in hypertensive adults. A total of 14 390 participants were included in the final analysis. A multivariate linear regression model was applied for the correlation analysis of WBC count and baPWV. Higher WBC counts were associated with a greater baPWV: adjusted β = 10 (95% CI, 8-13, P < .001). The same significant association was also found when WBC count was assessed as categories or quartiles. In addition, the effect of differential WBC subtypes, including neutrophil count and lymphocyte count on baPWV, showed the similar results. These findings showed that baPWV has positive associations with differential WBC counts in hypertensive adults.


2021 ◽  
Vol 11 (8) ◽  
pp. 3404
Author(s):  
Majid Hejazian ◽  
Eugeniu Balaur ◽  
Brian Abbey

Microfluidic devices which integrate both rapid mixing and liquid jetting for sample delivery are an emerging solution for studying molecular dynamics via X-ray diffraction. Here we use finite element modelling to investigate the efficiency and time-resolution achievable using microfluidic mixers within the parameter range required for producing stable liquid jets. Three-dimensional simulations, validated by experimental data, are used to determine the velocity and concentration distribution within these devices. The results show that by adopting a serpentine geometry, it is possible to induce chaotic mixing, which effectively reduces the time required to achieve a homogeneous mixture for sample delivery. Further, we investigate the effect of flow rate and the mixer microchannel size on the mixing efficiency and minimum time required for complete mixing of the two solutions whilst maintaining a stable jet. In general, we find that the smaller the cross-sectional area of the mixer microchannel, the shorter the time needed to achieve homogeneous mixing for a given flow rate. The results of these simulations will form the basis for optimised designs enabling the study of molecular dynamics occurring on millisecond timescales using integrated mix-and-inject microfluidic devices.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Deng Yan ◽  
Wang Yan-Fang ◽  
Zhu Shi-Yang ◽  
Ma Rui-Lin ◽  
Ding Xue-Song ◽  
...  

Abstract Background To describe the diagnostic criteria used and their application accuracy in the practice of polycystic ovary syndrome (PCOS) caring among obstetricians and gynaecologists across China. Methods This was an Online cross-sectional survey of Obstetricians and gynecologists involved in PCOS caring conducted via the largest continuing education platform of obstetrics and gynecology across China from September 2019 to November 2019. Results A total of 2,328 respondents were eligible for the final analysis. Of these, 94.5 % were general obstetricians and gynaecologists (Ge-ObGyn), and 5.5 % were reproductive endocrinologists (Re-ObGyn). Overall, the most frequently used criteria were the Androgen Excess and Polycystic Ovary Syndrome Society (AE-PCOS) criteria (48.2 %), followed by the Rotterdam criteria (35.7 %) and NIH criteria (12.1 %). Of the respondents, 31.3 % used their diagnostic criteria in their clinical practice. More respondents who chose the Rotterdam criteria could accurately apply the diagnostic criteria than those who chose the AE-PCOS criteria (41.2 % vs. 32.1 %, P < 0.001). Compared with Ge-ObGyn, Re-ObGyn were less likely to use the AE-PCOS criteria (adjusted odds ratio, 0.513; 95 % CI, 0.328–0.802; P < 0.05) and 1.492 times more likely to accurately use their criteria (95 % CI, 1.014–2.196; P < 0.05). Conclusions Less than one-third of obstetricians and gynaecologists across China could accurately use the diagnostic criteria they choose to diagnose PCOS. There is an urgent need to train obstetricians and gynaecologists on PCOS diagnosis in an effort to improve the medical care quality of patients with PCOS.


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