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

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.

2011 ◽  
Vol 178-179 ◽  
pp. 3-14 ◽  
Author(s):  
Vladimir V. Voronkov ◽  
Robert Falster

In dislocation-free silicon, intrinsic point defects – either vacancies or self-interstitials, depending on the growth conditions - are incorporated into a growing crystal. Their incorporated concentration is relatively low (normally, less than 1014 cm-3 - much lower than the concentration of impurities). In spite of this, they play a crucial role in the control of the structural properties of silicon materials. Modern silicon crystals are grown mostly in the vacancy mode and contain many vacancy-based agglomerates. At typical grown-in vacancy concentrations the dominant agglomerates are voids, while at lower vacancy concentrations there are different populations of joint vacancy-oxygen agglomerates (oxide plates). Larger plates – formed in a narrow range of vacancy concentration and accordingly residing in a narrow spatial band – are responsible for the formation of stacking fault rings in oxidized wafers. Using advanced crystal growth techniques, whole crystals can be grown at such low concentrations of vacancies or self-interstitials such that they can be considered as perfect.


2014 ◽  
Vol 64 (11) ◽  
pp. 13-18
Author(s):  
H. Yamada-Kaneta ◽  
K. Okabe ◽  
M. Akatsu ◽  
S. Baba ◽  
K. Mitsumoto ◽  
...  

2019 ◽  
Vol 33 (11) ◽  
pp. 63-72
Author(s):  
Hiroshi Yamada-Kaneta ◽  
Shotaro Baba ◽  
Yuta Nagai ◽  
Mitsuhiro Akatsu ◽  
Keisuke Mitsumoto ◽  
...  

1980 ◽  
Vol 2 ◽  
Author(s):  
A.J.R. de Kock

ABSTRACTDuring melt-growth of macroscopically dislocation free bulk silicon crystals (floating-zone and Czochralski technique) microdefects can form due to the condensation of thermal point defects (self-interstitials, vacancies). The formation of these imperfections, generally referred to as “swirl defects”, is strongly affected by the growth conditions (e.g. the crystal pulling rate) and crystal purity. The various reported defect formation models will be discussed. Special attention will be paid to the effect of doping on swirl defect formation.


2008 ◽  
Vol 19 (S1) ◽  
pp. 19-23 ◽  
Author(s):  
Hiroshi Yamada-Kaneta ◽  
Terutaka Goto ◽  
Yuichi Nemoto ◽  
Koji Sato ◽  
Masatoshi Hikin ◽  
...  

2009 ◽  
Vol 156-158 ◽  
pp. 135-138
Author(s):  
Hiroshi Yamada-Kaneta ◽  
Hajime Watanabe ◽  
Yuta Nagai ◽  
Shotaro Baba ◽  
Mitsuhiro Akatsu ◽  
...  

We confirm the following findings obtained in our previous experiment for the low-temperature elastic softening by the vacancies in boron-doped silicon crystals: (1) the steep softening that suddenly starts at 2-4 K in the cooling process, and (2) the complete disappearance of the softening by a weak magnetic field of 4 T applied along [111] direction. We further investigate in detail how the low-temperature softening at a fixed temperature responds to the applied magnetic field, to find the following characteristic anisotropy: The manner of disappearance of the softening strongly depends on the direction of the magnetic field. For the magnetic field imposed along [1-10] direction, nearly 60 % of the full softening still remains even at a strong magnetic field of 8 T, in contrast to the case of magnetic field applied along [111] direction.


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