Vacancies in Growth-Rate-Varied CZ Silicon Crystal Observed by Low-Temperature Ultrasonic Measurements

Author(s):  
Hiroshi Yamada-Kaneta ◽  
Terutaka Goto ◽  
Yuichi Nemoto ◽  
Koji Sato ◽  
Masatoshi Hikin ◽  
...  
2007 ◽  
Vol 131-133 ◽  
pp. 455-460 ◽  
Author(s):  
Hiroshi Yamada-Kaneta ◽  
Terutaka Goto ◽  
Yuichi Nemoto ◽  
Koji Sato ◽  
Masatoshi Hikin ◽  
...  

The low-temperature ultrasonic experiments are performed to measure the distribution of vacancy concentration in the ingot of the Czochralski (CZ) silicon crystal grown with the pulling rate gradually lowered. The elastic softening similar to that we recently found for the floating-zone-grown silicon crystals is observed for the so-called vacancy-rich region of the ingot which contains no voids or dislocation clusters. We further uncover that the interstitial-rich region in the ingot exhibits no such elastic softening, confirming our previous conclusion that the defects responsible for the low-temperature elastic softening are the vacancies. We also disclose that the elastic softening is absent for the ring-like oxidation stacking fault (R-OSF) region of the ingot. The measured distribution of the vacancy concentration indicates that the minority point defects are perfectly cancelled by the majority point defects during the CZ crystal growth.


2019 ◽  
Vol 3 (4) ◽  
pp. 375-385 ◽  
Author(s):  
Terutaka Goto ◽  
Hiroshi Yamada-Kaneta ◽  
Yasuhiro Saito ◽  
Yuichi Nemoto ◽  
Koji Sato ◽  
...  

2020 ◽  
Vol 96 (3s) ◽  
pp. 148-153
Author(s):  
С.Д. Федотов ◽  
А.В. Бабаев ◽  
В.Н. Стаценко ◽  
К.А. Царик ◽  
В.К. Неволин

Представлены результаты изучения морфологии поверхности и структуры слоев AlN, сформированных аммиачной МЛЭ на темплейтах 3C-SiC/Si(111) on-axis- и 4° off-axis-разориентации. Опробован технологический режим низкотемпературной эпитаксии зародышевого слоя AlN на поверхности 3C-SiC(111). Среднеквадратичная шероховатость поверхности (5 х 5 мкм) слоев AlN толщиной 150 ± 50 нм составила 2,5-3,5 нм на темплейтах 3C-SiC/Si(111) on-axis и 3,3-3,5 нм на 4° off-axis. Показано уменьшение шероховатости смачивающего слоя AlN при изменении скорости роста. Получены монокристаллические слои AlN(0002) со значениями FWHM (ω-геометрия) 1,4-1,6°. The paper presents the surface morphology and crystal structure of AlN layers formed by ammonia MBE on 3C-SiC/Si(111) on-axis and 4° off-axis disorientation. It offers the technological approach of low-temperature epitaxy of the AlN nucleation layer on the 3C-SiC (111) surface. Root mean square roughness (5 х 5 |xm) of AlN layers with thickness of 150 ± 50 nm was 2,5-3,5 nm onto on-axis templates and 3.3-3.5 nm onto 4° off-axis. It appears that the RMS roughness of the AlN surface is changing with the growth rate variation. Single-crystal AlN(0002) layers with FWHM values (ω-geometry) of 1.4-1.6° have been obtained.


2017 ◽  
Vol 15 (1) ◽  
Author(s):  
Rosa S. Santos ◽  
Marcus R. da Costa ◽  
Francisco G. Araújo

ABSTRACT Studies on age and growth of fish populations have direct application in fisheries and contribute for policies of conservation. Our aim was update information on the Micropogonias furnieri growth parameters based on sagittae otoliths annulis readings, and we expected that the studied population from Southeast Brazil can reach more longevity than the reported in the available literature. We examined 286 individuals between August-2010 and July-2011 from Ubatuba Bay, SP. The Total Length ranged 200-480 mm. The determined growth parameters were: Males, L∞ =523.4mm, k = 0.05×year-1, t0 = -8.78 year; Females L∞ = 573.5mm, k = 0.06 × year-1, t0 = -7.49 year. The MI and % of edge type evidenced the formation of one ring per year during autumn/winter, coinciding with low temperature and low growth rate. These results differed from those reported for the Vazzoler’s Population I (summer), and we detected higher longevity (45-48 years) as compared with the recorded in the available information.


2018 ◽  
Vol 22 (4) ◽  
pp. 1039-1054 ◽  
Author(s):  
Arash Farshidi ◽  
Christian Berggreen ◽  
Leif A Carlsson

This paper experimentally investigates the effects of low temperature on fracture toughness and fatigue debond growth rate in foam core sandwich composites. Mixed-mode bending specimens were statically and cyclically tested inside a climatic chamber at a low temperature (−20°C) and at room temperature (23°C) as a reference. Testing was conducted in mode I (opening) and mixed-mode I/II (opening-sliding) mode mixities. The fatigue tests results are presented according to the modified Paris–Erdogan relation. Results showed substantial fracture toughness reduction due to low temperature. Low temperature furthermore elevated the cyclic crack growth rate.


2018 ◽  
Vol 112 (4) ◽  
pp. 042101 ◽  
Author(s):  
Kevin L. Schulte ◽  
Anna Braun ◽  
John Simon ◽  
Aaron J. Ptak

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