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US 2020/0006490 A1Published application
High voltage device and manufacturing method thereof
AssigneeRichtek Technology Corporation
InventorTsung-Yi Huang
Life of this patent
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Abstract
An N-type high voltage device includes: a semiconductor layer, a well region, a floating region, a bias region, a body region, a body contact, a gate, a source and a drain. The floating region and the bias region both have P-type, and both are formed in a drift region in the well region. The bias region is electrically connected with a predetermined bias voltage, and the floating region is electrically floating, to increase a breakdown voltage of the high voltage device and suppressing turning-ON a parasitic transistor in the high voltage device.
Claims16
A high voltage device comprising:
- a semiconductor layer formed on a substrate, wherein the semiconductor layer has a top surface and a bottom surface opposite to the top surface in a vertical direction;
- a well region having a first conductivity, wherein the well region is formed beneath the top surface and in contact with the top surface;
- a floating region having a second conductivity, wherein the floating region is formed in the well region, beneath the top surface and in contact with in the top surface, the floating region having a first impurity concentration;
- a bias region having the second conductivity, wherein the bias region is formed in the well region, beneath the top surface and in contact with the top surface, the floating region having a second impurity concentration;
- a body region having the second conductivity, wherein the body region is formed beneath and in contact with the top surface and contacts the well region in a channel direction, the body region having a third impurity concentration, wherein the third impurity concentration is higher than the first impurity concentration and the second impurity concentration;
- a body electrode having the second conductivity, wherein the body electrode is formed in the body region, beneath the top surface and in contact with the top surface, to serve as an electrical contact of the body region;
- a gate formed on the top substrate, wherein a portion of the body region is located below the gate and in contact with the gate, to provide an inversion region of the high voltage device during ON operation of the high voltage device;
- and
- a source and a drain having the first conductivity, the source and the drain being formed beneath the top surface and in contact with the top surface in the vertical direction, wherein the source and the drain are respectively located at two lateral sides of the gate, the source being located in the body region, and the drain being located in the well region and away from the body region;
- wherein a portion of the well region between the body region and the drain serves as a drift region during ON operation of the high voltage device;
- wherein the floating region and the bias region are both in the drift region;
- wherein the bias region is electrically connected with a predetermined bias voltage and the floating region is electrically floating.
9 more elements
A manufacturing method of a high voltage device, comprising:
- forming a semiconductor layer on a substrate, wherein the semiconductor layer has a top surface and a bottom surface opposite to the top surface in a vertical direction;
- forming a well region having a first conductivity, wherein the well region is formed beneath the top surface and in contact with the top surface;
- forming a floating region having a second conductivity, wherein the floating region is formed in the well region, beneath the top surface and in contact with in the top surface, the floating region having a first impurity concentration;
- forming a bias region having the second conductivity, wherein the bias region is formed in the well region, beneath the top surface and in contact with the top surface, the floating region having a second impurity concentration;
- forming a body region having the second conductivity, wherein the body region is formed beneath and in contact with the top surface and contacts the well region in a channel direction, the body region having a third impurity concentration, wherein the third impurity concentration is higher than the first impurity concentration and the second impurity concentration;
- forming a body electrode having the second conductivity, wherein the body electrode is formed in the body region, beneath the top surface and in contact with the top surface, to serve as an electrical contact of the body region;
- forming a gate formed on the top substrate, wherein a portion of the body region is located below the gate and in contact with the gate, to provide an inversion region of the high voltage device during ON operation of the high voltage device;
- and
- forming a source and a drain having the first conductivity, the source and the drain being formed beneath the top surface and in contact with the top surface in the vertical direction, wherein the source and the drain are respectively located at two lateral sides of the gate, the source being located in the body region, and the drain being located in the well region and away from the body region;
- wherein a portion of the well region between the body region and the drain serves as a drift region during ON operation of the high voltage device;
- wherein the floating region and the bias region are both in the drift region;
- wherein the bias region is electrically connected with a predetermined bias voltage and the floating region is electrically floating.
9 more elements
Dependencies are inferred from the claim text.