Hitachi, Ltd.

Hiroo Usui

Yasuo Wada

Makoto Ohkura

Masanobu Miyao

Masao Tamura

Takashi Tokuyama

Mikio Ashikawa

Mitsumasa Koyanagi

A polycrystalline silicon film is implanted with an impurity in large amounts and is heated to be annealed, whereupon it is irradiated with a laser beam to be annealed. Thus, a polycrystalline silicon film of very low resistivity consisting of a second layer whose activated impurity concentration is equal to or below a solid solubility and a first layer whose activated impurity concentration is above the solid solubility is formed.

Stacked polycrystalline silicon film of high and low conductivity layers

A polycrystalline silicon layer is deposited by chemical vapor deposition method at a predetermined location on an oxide film grown by thermal oxidation on a surface of a monocrystal silicon substrate. Nitrogen ions are implanted in the outer surface of the polycrystalline silicon layer and the exposed surface of the oxide film. The whole surfaces are oxidized by wet oxidation so as to form a thick oxide layer at the surface of the oxide film which is not covered by the polycrystalline silicon layer.

Method for fabricating a silicon device utilizing ion-implantation and

Growing community of inventors

Machida, Japan

Hiroo Usui