Influence of Negative Charging on High Rate SiC Etching for GaN HEMT MMICs

We discuss the influence of negative charging on high-rate ICP etching of SiC via-holes for GaN HEMT MMICs. There is large differential etching behavior such as etch rate, etching profile, and RIE lag between S.I.- and n-SiC substrates because of the difference in wafer heating and negative charging of the sidewall during etching between both substrates. We analyze the difference in negative charging between both substrates by simulating the etching profile.

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Comparison Of F2 Plasma Chemistries For Deep Etching Of SiC

MRS Proceedings ◽

10.1557/proc-640-h7.7 ◽

2000 ◽

Vol 640 ◽

Author(s):

K. P. Lee ◽

P. Leerungnawarat ◽

S. J. Pearton ◽

F. Ren ◽

S. N. G. Chu ◽

...

Keyword(s):

Electrical Properties ◽

Etch Rate ◽

Low Cost ◽

Surface Region ◽

High Rate ◽

Near Surface ◽

Ion Energy ◽

Deep Etching ◽

Process Pressure ◽

Via Holes

ABSTRACTA number of F2-based plasma chemistries (NF3, SF6, PF5 and BF3) were investigated for high rate etching of SiC. The most advantageous of these is SF6, based on the high rate (0.6 μm · min−1) it achieves and its relatively low cost compared to NF3. The changes in electrical properties of the near-surface region are relatively minor when the incident ion energy is kept below approximately 75 eV. At a process pressure of 5 mTorr, the SiC etch rate falls-off by ∼15 % in 30 μm diameter via holes compared to larger diameter holes (> 60 μm diameter) or open areas on the mask.

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ICP ETCHING OF RF SPUTTERED AND PECVD SILICON CARBIDE FILMS

International Journal of Modern Physics B ◽

10.1142/s0217979202010877 ◽

2002 ◽

Vol 16 (06n07) ◽

pp. 1067-1071

Author(s):

J. SHI ◽

E. F. CHOR ◽

W. K. CHOI

Keyword(s):

Silicon Carbide ◽

Amorphous Silicon ◽

Etch Rate ◽

Chemical Vapour ◽

Amorphous Silicon Carbide ◽

Icp Etching ◽

Key Factor ◽

The Difference ◽

Amorphous Sic ◽

Hydrogenated Amorphous

In this paper, we report the Inductive Coupled Plasma (ICP) etching of RF sputtered unhydrogenated amorphous silicon carbide film (a-Si0.5C0.5) , and plasma enhanced chemical vapour deposited (PECVD) hydrogenated amorphous silicon carbide films (a-Si0.3C0.7:H and a-Si0.7C0.3:H) , asprepared and annealed, using CF4/O2 chemistry. The etch rate of amorphous SiC is observed to be closely related to the hydrogen content. The mechanism of etching is studied by varying the RIE power, ICP power and pressure. It has been suggested that the removal of surface polymers (CFx) is a key factor in the etching process. In order to study the difference in etch rate between sputtered and PECVD SiC and the effects of changing Si/C ratio, IR spectra are used to reveal the bonds density in the samples.

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Peritoneal Fluid and Plasma Fibrinolytic Activity in Women with Pelvic Inflammatory Disease

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656331 ◽

1992 ◽

Vol 68 (02) ◽

pp. 102-105 ◽

Cited By ~ 15

Author(s):

P J Dörr ◽

E J P Brommer ◽

G Dooijewaard ◽

H M Vemer

Keyword(s):

Pelvic Inflammatory Disease ◽

Inflammatory Disease ◽

Peritoneal Fluid ◽

Fibrinolytic Activity ◽

Degradation Products ◽

Adhesion Formation ◽

High Rate ◽

Control Group ◽

The Difference ◽

Fibrinolytic Parameters

SummaryPrevious studies have shown that the fibrinolytic activity of peritoneum is depressed in local inflammation. We measured fibrinolytic parameters in peritoneal fluid and in plasma of 10 women with pelvic inflammatory disease (PID). Nine women, in whom laparoscopy for sterilisation was performed, served as a control group.In the peritoneal fluid of women with PID, PAI-Ag, t-PA-Ag and u-PA-Ag were many times higher than in the control group. In contrast to the antigens which may be present in inert complexes, the potentially active compounds, measured as t-PA activity and plasmin-activable scu-PA, were not significantly different in the two groups, and in none of the samples was the active enzyme tcu-PA detectable. Nevertheless, the mean peritoneal fluid TDP and FbDP concentrations were about twenty times higher in the PID group than in the control group. In plasma of PID patients, none of the parameters except u-PA-Ag differed from those in the control group. The difference between control and patient plasma u-PA-Ag was statistically significant, but too small to attach any relevance to the observation.Our data suggest that, in contrast to the classical concept of decreased fibrinolytic activity as a cause of adhesion formation, intraperitoneal fibrinolysis is enhanced in peritoneal inflammation through stimulation of the local production of t-PA and u-PA. Despite concomitant production of PAI, fibrinolysis occurs at a high rate, resulting in high levels of fibrin degradation products. Since this activated fibrinolysis does not meet the demand, therapeutic enhancement should be considered to prevent adhesions.

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Two maize cultivars of contrasting leaf size show different leaf elongation rates with identical patterns of extension dynamics and coordination

AoB Plants ◽

10.1093/aobpla/plaa072 ◽

2021 ◽

Author(s):

Tiphaine Vidal ◽

Hafssa Aissaoui ◽

Sabrina Rehali ◽

Bruno Andrieu

Keyword(s):

Genotypic Variation ◽

Leaf Size ◽

High Rate ◽

Time Interval ◽

Extension Rate ◽

Leaf Production ◽

Maize Cultivars ◽

Plant Environment ◽

The Difference ◽

Leaf Extension

Abstract Simulating leaf development from initiation to maturity opens new possibilities to model plant–environment interactions and the plasticity of plant architecture. This study analyses the dynamics of leaf production and extension along a maize (Zea mays) shoot to assess important modelling choices. Maize plants from two cultivars originating from the same inbred line, yet differing in the length of mature leaves were used in this study. We characterised the dynamics of the blade and sheath lengths of all phytomers by dissecting plants every 2–3 days. We analysed how differences in leaf size were built up and we examined the coordination between the emergence of organs and phases of their extension. Leaf extension rates were higher in the cultivar with longer leaves than in the cultivar with shorter leaves; no differences were found in other aspects. We found that (i) first post-embryonic leaves were initiated at a markedly higher rate than upper leaves; (ii) below ear position, sheaths were initiated at a time intermediate between tip emergence and appearance, while above the ear position, sheaths were initiated at a high rate, such that the time interval between the blade and sheath initiations decreased for these leaves; and (iii) ear position also marked a change in the correlation in size between successive phytomers with little correlation of size between upper and lower leaves. Our results identified leaf extension rate as the reason for the difference in size between the two cultivars. The two cultivars shared the same pattern for the timing of initiation events, which was more complex than previously thought. The differences described here may explain some inaccuracies reported in functional-structural plant models. We speculate that genotypic variation in behaviour for leaf and sheath initiation exists, which has been little documented in former studies.

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A Low-Dimensional Dissimilarity Analysis of Unilateral and Bilateral Stroke-Impacted Hand Trajectories

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.4033836 ◽

2016 ◽

Vol 138 (11) ◽

Cited By ~ 1

Author(s):

Jay Ryan U. Roldan ◽

Dejan Milutinović ◽

Zhi Li ◽

Jacob Rosen

Keyword(s):

Multidimensional Scaling ◽

Healthy Subject ◽

Motion Capture ◽

Early Phase ◽

Three Dimensional ◽

High Rate ◽

Motion Capture System ◽

Trajectory Data ◽

The Difference ◽

Low Dimensional

In this paper, we propose a quantitative approach based on identifying hand trajectory dissimilarities through the use of a multidimensional scaling (MDS) analysis. A high-rate motion capture system is used to gather three-dimensional (3D) trajectory data of healthy and stroke-impacted hemiparetic subjects. The mutual dissimilarity between any two trajectories is measured by the area between them. This area is used as a dissimilarity variable to create an MDS map. The map reveals a structure for measuring the difference and variability of individual trajectories and their groups. The results suggest that the recovery of hemiparetic subjects can be quantified by comparing the difference and variability of their individual MDS map points to the points from the cluster of healthy subject trajectories. Within the MDS map, we can identify fully recovered patients, those who are only functionally recovered, and those who are either in an early phase of, or are nonresponsive to the therapy.

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Limited Tissue Biopsies and Hematolymphoid Neoplasms

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqz107 ◽

2019 ◽

Vol 152 (6) ◽

pp. 782-798

Author(s):

Kimberly F Ingersoll ◽

Yue Zhao ◽

Grant P Harrison ◽

Yang Li ◽

Lian-He Yang ◽

...

Keyword(s):

B Cell ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Excisional Biopsy ◽

Needle Aspiration ◽

High Rate ◽

P Value ◽

History Of ◽

Primary Neoplasms ◽

The Difference

Abstract Objectives Use of fine-needle aspiration/needle core biopsy (FNA/CNB) in evaluating hematolymphoid processes has been debated. We investigate its applicability in various clinicopathologic settings. Methods We retrospectively analyzed 152 cases of FNA/CNB. Results Of 152 FNA/CNBs, 124 (81.6%) resulted in diagnoses without excisional biopsies, while 28 required subsequent excisional biopsies. Of these, 43 FNA/CNBs performed for suspected lymphoma relapse demonstrated 95.4% diagnostic rate (41/43), which was significantly better than those without history of lymphoma (77/109, 71%; odds ratio [OR], 8.5; confidence interval, 1.9-37.4). Patients with immunodeficiency also showed a high rate of diagnosis by FNA/CNB (100%). When stratified by types of disease, diffuse large B-cell lymphoma/high-grade B-cell lymphoma demonstrated a higher success rate (92.7%) than small B-cell lymphoma (79.2%), though the difference was not statistically significant (OR, 3.3; P value = .07). A subsequent excisional biopsy was required in 28 cases, 23 of which resulted in diagnoses concordant with the FNA/CNB. Five cases showed diagnostic discordance, reflecting pitfalls of FNA/CNB in unusual cases with complex pathology. Conclusions FNA/CNB is practical in evaluating most hematolymphoid lesions, with high efficacy in recurrent disease and some primary neoplasms with homogeneous/ aggressive histology, or characteristic immunophenotype.

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Small Bowel Adenocarcinomas Featuring Special AT-Rich Sequence-Binding Protein 2 (SATB2) Expression and a Colorectal Cancer-Like Immunophenotype: A Potential Diagnostic Pitfall

Cancers ◽

10.3390/cancers12113441 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3441

Author(s):

Giuseppe Neri ◽

Giovanni Arpa ◽

Camilla Guerini ◽

Federica Grillo ◽

Marco Vincenzo Lenti ◽

...

Keyword(s):

Small Bowel ◽

Colorectal Carcinoma ◽

Binding Protein ◽

Statistical Significance ◽

Expression Patterns ◽

High Rate ◽

Unknown Primary ◽

Diagnostic Pitfall ◽

Pathologic Features ◽

The Difference

Special AT-rich sequence-binding protein 2 (SATB2) is a transcription factor expressed by colonic cryptic epithelium and epithelial neoplasms of the lower gastrointestinal (GI) tract, as well as by small bowel adenocarcinomas (SBAs), though at a lower rate. Nevertheless, up to now, only small SBA series, often including a very limited number of Crohn’s disease-associated SBAs (CrD-SBAs) and celiac disease-associated SBAs (CD-SBA), have been investigated for SATB2 expression. We evaluated the expression of SATB2 and other GI phenotypic markers (cytokeratin (CK) 7 and CK20, caudal type homeobox 2 (CDX2) and alpha-methylacyl-CoA racemase (AMACR)), as well as mismatch repair (MMR) proteins, in 100 SBAs, encompassing 34 CrD-SBAs, 28 CD-SBAs and 38 sporadic cases (Spo-SBAs). Any mutual association and correlation with other clinico-pathologic features, including patient prognosis, were searched. Twenty (20%) SATB2-positive SBAs (4 CrD-SBAs, 7 CD-SBAs and 9 Spo-SBAs) were identified. The prevalence of SATB2 positivity was lower in CrD-SBA (12%) in comparison with both CD-SBAs (25%) and Spo-SBAs (24%). Interestingly, six SBAs (two CD-SBAs and four Spo-SBAs) displayed a full colorectal carcinoma (CRC)-like immunoprofile (CK7−/CK20+/CDX2+/AMACR+/SATB2+); none of them was a CrD-SBA. No association between SATB2 expression and MMR status was observed. Although SATB2-positive SBA patients showed a more favorable outcome in comparison with SATB2-negative ones, the difference did not reach statistical significance. When cancers were stratified according to CK7/CK20 expression patterns, we found that CK7−/CK20- SBAs were enriched with MMR-deficient cases (71%) and patients with CK7−/CK20− or CK7−/CK20+ SBAs had a significantly better survival rate compared to those with CK7+/CK20− or CK7+/CK20+ cancers (p = 0.002). To conclude, we identified a small (6%) subset of SBAs featuring a full CRC-like immunoprofile, representing a potential diagnostic pitfall in attempts to identify the site of origin of neoplasms of unknown primary site. In contrast with data on colorectal carcinoma, SATB2 expression is not associated with MMR status in SBAs. CK patterns influence patient survival, as CK7−/CK20− cancers show better prognosis, a behavior possibly due to the high rate of MMR-deficient SBAs within this subgroup.

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ICP Etching of 4H-SiC Substrates

Materials Science Forum ◽

10.4028/www.scientific.net/msf.740-742.825 ◽

2013 ◽

Vol 740-742 ◽

pp. 825-828 ◽

Cited By ~ 5

Author(s):

Jerome Biscarrat ◽

Jean François Michaud ◽

Emmanuel Collard ◽

Daniel Alquier

Keyword(s):

Process Parameters ◽

Plasma Etching ◽

Inductively Coupled Plasma ◽

Etch Rate ◽

Effective Technique ◽

Working Pressure ◽

Inductively Coupled ◽

Icp Etching ◽

High Etch Rate ◽

The Impact

Due to its inert chemical nature, plasma etching is the most effective technique to pattern SiC. In this paper, dry etching of 4H-SiC substrate in Inductively Coupled Plasma (ICP) has been studied in order to evaluate the impact of process parameters on the characteristics of etching such as etch rate and trenching effect. Key process parameters such as platen power and ICP coil power prove to be essential to control the SiC etch rate. On the other hand, the ICP coil power and the working pressure mainly master the trenching effect. Our results enlighten that high etch rate with minimal trenching effect can be obtained using high ICP coil power and low working pressure.

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Birth Weight Distribution as an Indicator of Environmental Effects on Fetal Development

Scandinavian Journal of Social Medicine ◽

10.1177/140349488701500103 ◽

1987 ◽

Vol 15 (1) ◽

pp. 11-17 ◽

Cited By ~ 11

Author(s):

Anders Ericson ◽

Margareta Eriksson ◽

Bengt Källén ◽

Olav Meirik

Keyword(s):

Birth Weight ◽

Weight Distribution ◽

Social Groups ◽

Marked Change ◽

High Rate ◽

Low Birth Weight Infants ◽

Birth Registry ◽

Low Socioeconomic ◽

The Difference ◽

Birth Weight Distribution

A medical birth registry was used for a geographical analysis of birth weight distribution. Nearly 900 000 Swedish singleton births, 1973–1981, were used for an analysis of the effect of some variables and for standardization for these variables. A marked change in the rate of low birth weight infants (LBW, <2 500 g) was seen in the country between 1976 and 1977. A U-formed effect of maternal age and of parity was demonstrated. A marked interaction between the effects of these two variables existed. Two social groups were compared and the well-known high rate of LBW infants associated with low socioeconomic conditions was demonstrated. Standardization for the variables mentioned influenced this effect only little but reduced the difference between the social groups concerning infants above 3.5 kg weight. The background data were used for analysis of restricted geographical areas.

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