Shin-etsu Chemical Co., Ltd.

Kenji Itou

Yoshihiro Kubota

Nobuo Kawada

Noboru Kimura

Kesazi Harada

Proposed is a novel vessel such as crucibles made from PBN (pyrolytic boron nitride), which is highly resistant against exfoliation of the surface layer and suitable for use, for example, as a container of the melt in the Czochralski single crystal growing of III-V Group compound semiconductor single crystals with an improvement in the serviceable life. The PBN-made vessel of the invention is characterized by specific values of several parameters including density, which should be in the range from 1.90 to 2.05 g/cm.sup.3, intensity ratio of the X-ray diffraction peaks representing the degree of orientation, heat conductivity coefficient and the like. The above mentioned advantageous serviceable life of the vessel can be obtained only when these parameter values are satisfied.

Vessel made from pyrolytic boron nitride

An improved double-layered ceramic heater, which is used for heating a semiconductor silicon wafer mounted thereon in the processing of semiconductor devices, is proposed to be freed from the problems in the prior art ceramic heaters in respects of service life and contamination of silicon wafers mounted thereon. Different from conventional ceramic heaters having a ceramic substrate plate of, for example, boron nitride provided with a heater element layer of a metal foil, the inventive ceramic heater has a substrate plate of silicon nitride and a heater element layer of graphite is formed thereon by the CVD method so that the ceramic heater is not responsible for contamination of semiconductor silicon by virtue of absence of any element which can be a disturbing dopant of the semiconductor. The problem of contamination with carbon can be solved by further providing a coating layer of silicon nitride by the CVD method.

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Gunma, Japan

Kenji Itou