Mitsubishi Materials Corporation

Mitsubishi Materials Silicon Corporation

Sumco Corporation

Kazuhiro Ikezawa

Hiroshi Yasuda

Hiroyuki Kojima

Koji Hosoda

Akira Tanikawa

Yoshifumi Kobayashi

Ken Nakajima

Hideki Fujiwara

Hiroaki Taguchi

Toshinori Ishii

Hiroyuki Shiraki

Tamiya Karashima

Naofumi Iwamoto

Takashi Komekyu

This silicon electrode plate for plasma etching is a silicon electrode plate for plasma etching with superior durability including silicon single crystal which, in terms of atomic ratio, contains 3 to 11 ppba of boron, and further contains a total of 0.5 to 6 ppba of either or both of phosphorus and arsenic.

Silicon electrode plate for plasma etching with superior durability

A wafer of the invention is a silicon wafer of 0.02 &OHgr;cm or less in resistivity for deposition of an epitaxial layer, and the number of crystal originated particles (COP) and the number of interstitial-type large dislocation loops (L/D) are respectively 0 to 10 per wafer. A wafer of the invention is an epitaxial wafer having an epitaxial layer being 0.1 &OHgr;cm or more in resistivity and 0.5 to 5 &mgr;m in thickness formed on this wafer by means of a CVD method. A wafer of the invention is OSF-free and hardly makes traces of COP and L/D appear on the surface of an epitaxial layer when the epitaxial layer is formed. By heat treatment in a semiconductor device manufacturing process after the epitaxial layer is formed, BMDs occur uniformly and highly in density in the wafer and a uniform IG effect can be obtained in the wafer.

Epitaxial wafer

A monocrystal pulling apparatus according to the Czochralski technique, provided with a flow controller which guides a carrier gas supplied from the top of a pulling cheer to the surface of a melt of a material forming the monocrystal and exhausts the silicon oxide vaporizing from the surface of the melt to the outside of the pulling chamber and which surrounds the pulled monocrystal near the surface of the melt and is provided partially inside a crucible, wherein the flow controller has a tubular portion which has an outer diameter smaller than the inner diameter of the crucible and extends substantially perpendicularly along the direction of downward flow of the carrier gas, a constricted diameter portion which constricts in diameter from the bottom end of the tubular portion and forms a bottom gap with the pulled monocrystal, and an engagement portion which projects out from the top of the tubular portion and forms a top gap at the outer circumference of the tubular portion of the flow controller by supporting the flow controller partially in the pulling chamber. As a result, a first flow path through which the carrier gas flows toward said bottom gap is defined between the inside of the tubular portion and the pulled monocrystal, a second flow path is defined comprised of a flow path of the carrier gas passing through the top gap and a flow path of the carrier gas passing from the first flow path through the bottom gap and then passing between the surface of the silicon melt and flow controller. The silicon oxide is exhausted together with the carrier gas through the second flow path to the outside of the pulling chamber.

Method of exhausting silicon oxide

A monocrystal pulling apparatus according to the Czochralski technique, provided with a flow controller which guides a carrier gas supplied from the top of a pulling chamber to the surface of a melt of a material forming the monocrystal and exhausts the silicon oxide vaporizing from the surface of the melt to the outside of the pulling chamber and which surrounds the pulled monocrystal near the surface of the melt and is provided partially inside a crucible, wherein the flow controller has a tubular portion which has an outer diameter smaller than the inner diameter of the crucible and extends substantially perpendicularly along the direction of downward flow of the carrier gas, a constricted diameter portion which constricts in diameter from the bottom end of the tubular portion and forms a bottom gap with the pulled monocrystal, and an engagement portion which projects out from the top of the tubular portion and forms a top gap at the outer circumference of the tubular portion of the flow controller by supporting the flow controller partially in the pulling chamber. As a result, a first flow path through which the carrier gas flows toward said bottom gap is defined between the inside of the tubular portion and the pulled monocrystal, a second flow path is defined comprised of a flow path of the carrier gas passing through the top gap and a flow path of the carrier gas passing from the first flow path through the bottom gap and then passing between the surface of the silicon melt and flow controller. The silicon oxide is exhausted together with the carrier gas through the second flow path to the outside of the pulling chamber.

System for pulling-up monocrystal and method of exhausting silicon oxide

Growing community of inventors

Tokyo, Japan

Kazuhiro Ikezawa