Kabushiki Kaisha Toshiba

Shigeo Yawata

Shun-ichi Hiraki

Yoshiro Baba

Akihiko Osawa

Shizue Hori

Yoshikazu Usuki

Shigeru Moriyama

Jun-ichi Okano

Kazuhisa Shibao

The object of the present invention is to provide a method of manufacturing high-performance, high-breakdown-voltage semiconductor devices which suppresses an increase in the junction leakage current due to heavy metal contamination without increasing the number of manufacturing steps. A method of manufacturing semiconductor devices according to the invention, comprises the steps of ion-implanting one or more elements selected from a group of silicon, carbon, nitrogen, oxygen, hydrogen, argon, helium, and xenon into at least one surface of a semiconductor substrate of a first conductivity type at a dose of 1.times.10.sup.15 cm.sup.-2 or more to form a distortion layer, oxidizing the surface of the substrate to form an oxide film, ion-implanting impurities of a second conductivity type at a low concentration (a dose of less than 1.times.10.sup.15 cm.sup.-2) via the oxide film into the one surface of the substrate, ion-implanting impurities of the second conductivity type at a high concentration (a dose of 1.times.10.sup.15 cm.sup.-2 or more) via the oxide film into the other surface of the substrate, and forming a junction by heat treatment.

Semiconductor device

According to this invention, there is provided to a method of manufacturing semiconductor devices including the steps of ion-implanting at least one impurity selected from As, P, Sb, Si, B, Ga, and Al in a wafer prior to a predetermined manufactural process of semiconductor devices in the semiconductor wafer grown by the Czochralski technique, and thereafter annealing the wafer at a temperature of at least 900.degree. C. Nonuniformity of an impurity concentration of the wafer can be improved. The difference in characteristics among the semiconductor devices manufactured in the wafer is decreased, a product yield can be increased, and the quality of the semiconductor devices can be improved.

Method of rendering the impurity concentration of a semiconductor wafer

In order to eliminate unwanted crystal defects generated by an ion implantation, a semiconductor substrate or an epitaxial layer, which is selectively subjected to an impurity ion implantation, is heat-treated in an inert gas atmosphere at 850.degree. to 1050.degree. C. to recrystallize the implanted region. Thereafter, the semiconductor substrate is heat-treated at 900.degree. to 1250.degree. C. in an atmosphere containing oxygen. For eliminating abnormal growth of grain boundaries in a polycrystalline semiconductor layer deposited on an insulating film the semiconductor layer is heat-treated at 900.degree. to 1100.degree. C. in an atmosphere containing oxygen. By applying at least one of these processes to usual fabrication methods, semiconductor devices with high reliabilty such as power MOSFETs will be provided.

Method of manufacturing semiconductor device

Growing community of inventors

Hyogo, Japan

Shigeo Yawata