Single-crystal – oriented-crystal – and epitaxy growth processes; – Processes of growth with a subsequent step acting on the...
Patent
1995-07-06
1997-03-11
Breneman, R. Bruce
Single-crystal, oriented-crystal, and epitaxy growth processes;
Processes of growth with a subsequent step acting on the...
117 19, C30B 1510
Patent
active
056096828
ABSTRACT:
An improved method is proposed for the preparation of a semiconductor silicon single crystal of N-type by the Czochralski process, which is free from the problem of occurrence of delayed OSFs as defects in the single crystal even after prolonged storage at room temperature based on the discovery that presence of a certain amount of aluminum in the melt of silicon contained in a fused silica glass crucible acts to suppress occurrence of delayed OSFs as a type of defects in the single crystal while copper as an impurity acts adversely in this regard. With a known fact that an about 30 .mu.m thick inner surface layer of the crucible is melted down into the silicon melt during the single crystal pulling-up process, namely, the invention proposes use of a crucible of which the inner surface layer of 30 .mu.m thickness contains aluminum in an average concentration of 40 to 500 ppm by weight while the content of copper is as low as possible not to exceed 0.5 ppb by weight. Alternatively, when the fused silica glass crucible is deficient in the content of aluminum, an amount of aluminum is introduced as a dopant into the melt of silicon in the crucible to supplement the content of aluminum in order to be sufficient to suppress delayed OSFs.
REFERENCES:
patent: 5053359 (1991-10-01), Loxley et al.
patent: 5389582 (1995-02-01), Loxley et al.
Patent Abstracts Of Japan, vol. 16, No. 329, (C-093), 17 Jul. 1992.
Patent Abstracts Of Japan, vol. 12, No. 444, (C-545), 22 Nov. 1988.
Patent Abstracts Of Japan, vol. 14, No. 446, (C-763), 25 Sep. 1990.
Patent Abstracts Of Japan, vol. 16, No. 356, (C-969), 31 Jul. 1992.
Kemmochi Katsuhiko
Sakurada Masahiro
Sato Wataru
Tomohiko Ohta
Breneman R. Bruce
Garrett Felisa
Shin-Etsu Handotai & Co., Ltd.
Shin-Etsu Quartz Co., Ltd.
LandOfFree
Method for the preparation of silicon single crystal does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for the preparation of silicon single crystal, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for the preparation of silicon single crystal will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-440060