Denso Corporation

Nippondenso Co., Ltd.

Noriyuki Iwamori

Hiroaki Himi

Takeshi Kuzuhara

Yasushi Higuchi

Mitsutaka Katada

Hiroyuki Yamane

Tsutomu Kawaguchi

Masahiko Ishii

Akira Kuroyanagi

Shoji Miura

Mikimasa Suzuki

Takashi Suzuki

Hirofumi Funahashi

Atsushi Komura

Manabu Koike

Kenji Nakashima

Jiro Sakata

An epitaxial layer is formed on a high-resistance semiconductor substrate containing interstitial oxygen at a high concentration, and then a heat treatment is performed to the semiconductor substrate at a high temperature in an oxidizing atmosphere. Accordingly, a stratiform region of SiOis formed by deposition at an interface between the epitaxial layer and the semiconductor substrate. As a result, an apparent SOI substrate for an SOI semiconductor device can be manufactured at a low cost.

Method for manufacturing semiconductor substrate

In a semiconductor device such as MOSFET, a single crystal semiconductor substrate is provided. An epitaxitial layer is formed on the single crystal semiconductor substrate. A p-well regions are formed on the epitaxitial layer, respectively, and nsource regions are formed on the p-well regions, respectively. A gate electrode is formed through a gate insulation film on a part of each p-well region and that of each nsource region. The gate electrode is covered with an insulation film. On the insulation film, a source electrode is formed so that the n-channel MOSFET includes body diodes BD imbedded therein. A drain electrode is formed on the single crystal semiconductor substrate. A cluster-containing layer is implanted in the single crystal semiconductor substrate as a gettering layer so that the cluster-containing layer contains a cluster of nitrogen.

Semiconductor device

An epitaxial layer is formed on a high-resistance semiconductor substrate containing interstitial oxygen at a high concentration, and then a heat treatment is performed to the semiconductor substrate at a high temperature in an oxidizing atmosphere. Accordingly, a stratiform region of SiO is formed by deposition at an interface between the epitaxial layer and the semiconductor substrate. As a result, an apparent SOI substrate for an SOI semiconductor device can be manufactured at a low cost.

A semiconductor device having an enhancement-type MOS structure which can prevent large leakage current is disclosed. A high-concentration region for threshold-value regulation use formed in a channel region below a gate electrode in an enhancement-type transistor is caused to be contiguous with a source region and not contiguous with a drain region. Herein, the distance between the high-concentration region and the drain region is set so as to preclude the depletion layer extending from the drain region side from reaching the high-concentration region. Therefore, the electrical field in the depletion layer does not become the critical field which causes avalanche or Zener breakdown, and so leakage current can be caused to be reduced.

Semiconductor device and fabrication process thereof

In a method of manufacturing a semiconductor device, after performing ion-implantation and before forming an oxide film, a silicon substrate is disposed within a furnace to undergo a heat treatment at a temperature equal to or higher than 950&deg; C. for a specific time period (equal to or longer than 15 minutes). When performing the heat treatment and when raising a temperature up to the heat treatment temperature, oxygen is supplied together with nitrogen gas (inert gas). A supply amount of oxygen is controlled to be equal to or less than 5% when raising the temperature up to the heat treatment temperature, and to be equal to or less than 2% when performing the heat treatment. After the heat treatment, the oxidation film is formed. As a result, crystal defects (OSFs) are prevented from being produced on the silicon substrate surface.

Method of manufacturing semiconductor device

Enhancement-type semiconductor having reduced leakage current

Growing community of inventors

Okazaki, Japan

Noriyuki Iwamori