Semiconductor switch device
AssigneeRohm Co., Ltd.
InventorMasaru Takaishi
Life of this patent
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Abstract
Provided is a semiconductor device in which on-resistance is largely reduced. The semiconductor device includes an n type epitaxial layer in which each region between neighboring trenches becomes a channel, and a plurality of embedded electrodes each of which is formed on an inner surface of each trench via a silicon oxide film. The plurality of embedded electrodes include two types of embedded electrodes to which voltages are applied separately. By blocking each region between neighboring trenches with a depletion layer formed around every trench, current flowing through each region between the neighboring trenches is interrupted. By deleting the depletion layer formed around the trench filled with the embedded electrode, current can flow through each region between neighboring trenches.
Claims14
A semiconductor device comprising:
- a semiconductor layer of one conductivity type including a plurality of trenches arranged with predetermined spaces, so that each region between the neighboring trenches becomes a channel;
- and
- a plurality of embedded electrodes each of which is formed on an inner surface of each of the plurality of trenches via an insulator film so as to fill in each of the plurality of trenches,
- the semiconductor device switching between an on state and an off state according to a voltage applied to the plurality of embedded electrodes,
- wherein the plurality of trenches have substantially the same width and substantially the same depth as one another,
- wherein all semiconductor material adjacent the trenches is of the one conductivity type,
- wherein a concentration of an impurity of the one conductivity type is substantially the same in the channel of the semiconductor layer and in a region of the semiconductor layer on a bottom side of the plurality of trenches,
- wherein the plurality of embedded electrodes include two types, which are a first embedded electrodes and second embedded electrodes to which voltages are applied separately, and
- wherein
- in the off state, each depletion layer formed around any of the plurality of trenches blocks a region between the neighboring trenches, and
- in the on state, a depletion layer, formed around any of the plurality of trenches in which the first type of embedded electrode is embedded, disappears to permit current to flow through the region between the neighboring trenches.
A semiconductor device comprising:
- a semiconductor layer of one conductivity type including a plurality of trenches arranged with predetermined spaces, so that each region between the neighboring trenches becomes a channel;
- a first embedded electrode filled in a predetermined trench among the plurality of trenches via an insulator film;
- and
- a second embedded electrode filled in a trench other than the trench filled with the first embedded electrode, so as to be applied with a voltage separately from the first embedded electrode and to have a Schottky contact with the semiconductor layer inside the trench,
- the semiconductor device switching between an on state and an off state according to a voltage applied to the plurality of embedded electrodes,
- wherein the plurality of trenches have substantially the same width and substantially the same depth as one another,
- wherein semiconductor material neighboring the trenches is only of the one conductivity type,
- wherein a concentration of an impurity of the one conductivity type is substantially the same in the channel of the semiconductor layer and in a region of the semiconductor layer on a bottom side of the plurality of trenches, and
- wherein
- in the off state, every depletion layer formed around the trenches blocks a region between the neighboring trenches, and
- in the on state, a depletion layer, formed around any of the plurality of trenches in which the first type of embedded electrode is embedded, disappears to permit current to flow through the region between the neighboring trenches.
Dependencies are inferred from the claim text.