Modeling of hot-carrier degradation of p-MOSFET?s

Bu çalışmanın amacı, sıcak taşıyıcılar nedeniyle p-MOSFET’lerde oluşan parametre yorulmaların analog uygulamalara uygun modellenmesidir. Tümdevre elemanların çalışmaları süresince sıcak taşıyıcıların neden olduğu elektronların tuzaklara yakalanma ve/veya tuzaklar oluşturma ve/veya yüzey tuzaklar oluşturması sonucunda oksit yükü ve tuzak yoğunluğu değişmektedir. Bu güne kadar sıcak taşıyıcıların oluşumu ve modellenmesi üzerinde çok sayıda çalışma bulunmaktadır. Fakat, bu araştırmaların tamamına yakını sayısal uygulamalar, için yapılmıştır. Analog uygulamalar, sayısal uygulamalara göre bir çok noktada farklılıklar göstermektedir. Önerilen model, sıcak taşıyıcı yorulma modelini ve ömür tahmin etme modelini, analog uygulamalarına uygun olarak, tek bir model olarak yeniden geliştirmiştir. Geliştirilen modelin simülasyon sonuçları, ölçüm sonuçları ile doğrulanmaktadır.Anahtar Kelimeler: Güvenilirlik, MOSFET modelleri, sıcak taşıyıcılar, sıcak taşıyıcıların ömür tahmini, SPICE simülasyonu.The focus of this paper is the modeling of parameter degradation reliability of p-MOS transistors due to the hot-carriers under analog operation. Hot-carrier failure cause can initiate the electron trapping/generation and/or interface trap creation mechanism leading to changes of oxide charge and trap densities during device operation. A lot of efforts have been devoted to study the mechanisms due to the hot-carrier and modeling the device degradation due to these effects. However, these modelings are often performed on digital applications. Analog applications differ from digital ones by a number of points. Analog circuit reliability prediction has to take analog circuit design variables such as channel length, biasing conditions, and circuit topography into consideration. In order to achieve highest possible speed, smallest area and smallest power consumption usually L=Lmin are chosen for digital applications. However, for nearly all-analog applications this choice is inadequate because analog circuits usually use long-channel devices, the influence of hot-carrier effects on analog circuit performance has been believed to be minimal and, as a result, has been mostly overlooked. Therefore, the most important device parameters in these two application fields do not coincide. The proposed model includes a hot-carrier degradation model and a lifetime prediction model as a single model suitable for analog applications. The accuracy of the presented models has been verified with experimental data. Keywords: Hot-carrier, hot-carrier life time prediction, MOSFET models, SPICE simulation, reliability

First comprehensive assessment of the conservation status of the flora of the Çukurova Deltas, southern Turkey

The Çukurova Deltas on the southern coast of Turkey, with their high biodiversity, are one of the most important wetland and RAMSAR sites in the eastern Mediterranean basin. The total native flora comprises 600 plant taxa, including many endemic and threatened taxa. In an examination of this flora, 62 taxa (31 endemic and 31 rare taxa for Turkey) were categorized as having restricted distributions and being under threat of extinction. To assess the conservation status of the threatened flora, the IUCN Red List categories and criteria were applied at both a regional and global scale. The distribution of threatened flora in the study area was analysed in relation to four principle habitats: sand dunes (mobile or fixed) and sandy beaches (with 64.5% of all taxa), salt flats and salt water marshes (16.1%), river banks and fresh water marshes (9.7%), and field margins and roadsides (9.7%). Sand dunes and sandy beaches were identified as the most threatened habitats, being both sensitive to disturbance and heavily affected by humans. This Red Data List is a first step towards the recognition of conservation problems in the Çukurova Deltas and the need for more effective conservation of their flora. © 2005 FFI

Comparison of oxidant/antioxidant balance in COPD and non-COPD smokers

PMID = 3137103

New national and regional bryophyte records, 15

[No abstract available

Taxonomically-related word pairs evoke both N400 and LPC at long SOA in Turkish

Semantic priming in Turkish was examined in 36 right-handed healthy participants in a delayed lexical decision task via taxonomic relations using EEG. Prime-target relations included related- unrelated- and pseudo-words. Taxonomically related words at long stimulus onset asynchrony (SOA) were shown to modulate N400 and late positive component (LPC) amplitudes. N400 semantic priming effect in the time window of 300-500 ms was the largest for pseudo-words, intermediate for semantically-unrelated targets, and smallest for semantically-related targets as a reflection of lexical-semantic retrieval. This finding contributes to the ERP literature showing how remarkably universal the N400 brain potential is, with similar effects across languages and orthography. The ERP data also revealed different influences of related, unrelated, and pseudo-word conditions on the amplitude of the LPC. Attention scores and mean LPC amplitudes of related words in parietal region showed a moderate correlation, indicating LPC may be related to relationship-detection process.Ankara University Scientific Research Projects Coordination Unit [16L02000001]This research was supported by Ankara University Scientific Research Projects Coordination Unit with project number 16L02000001