A semiconductor device includes a plurality of epitaxial layers stacked over a supportive substrate, a first buried impurity region formed to share the supportive substrate with a lowermost epitaxial layer among the multiple epitaxial layers, one or more second buried impurity regions formed to be coupled with the first buried impurity region and share an N.sup.th epitaxial layer and an (N+1).sup.th epitaxial layer among the multiple epitaxial layers, where N is a natural number, a body region formed in an uppermost epitaxial layer among the multiple epitaxial layers and a deep well formed in the uppermost epitaxial layer to surround the body region and to be coupled with the second buried impurity regions that share the uppermost epitaxial layer.

A semiconductor device is provided. The device includes a substrate having a first conductivity type. The device further includes a drain region, a source region, and a well region disposed in the substrate. The well region is disposed between the drain region and the source region and having a second conductivity type opposite to the first conductivity type. The device further includes a plurality of doped regions disposed within the well region. The doped regions are vertically and horizontally offset from each other. Each of the doped regions includes a lower portion having the first conductivity type, and an upper portion stacked on the lower region and having the second conductivity type.

An LDFET is disclosed. A source region is electrically coupled to a source contact. A lightly doped drain (LDD) region has a lower dopant concentration than the source region, and is separated from the source region by a channel. A highly doped drain region forms an electrically conductive path between a drain contact and the LDD region. A gate electrode is located above the channel and separated from the channel by a gate dielectric. A shield plate is located above the gate electrode and the LDD region, and is separated from the LDD region, the gate electrode, and the source contact by a dielectric layer. A control circuit applies a variable voltage to the shield plate that: (1) accumulates a top layer of the LDD region before the transistor is switched on; and (2) depletes the top layer of the LDD region before the transistor is switched off.

The present invention provides a method of forming a passivation layer of a MOS device, and a MOS device. The method of forming a passivation layer of a MOS device includes: forming a substrate; forming a dielectric on the substrate; patterning the dielectric to expose a part of the substrate; forming a metal on the exposed part of the substrate, and the dielectric; forming a TEOS on the metal; forming a PSG on the TEOS; and forming a silicon nitrogen compound on the PSG. Therefore, the cracks problem of the passivation can be alleviated.

A semiconductor device having a first load terminal, a second load terminal and a semiconductor body is presented. The semiconductor body comprises an active region configured to conduct a load current between the first load terminal and the second load terminal and a junction termination region surrounding the active region. The semiconductor body includes a drift layer arranged within both the active region and the junction termination region and having dopants of a first conductivity type at a drift layer dopant concentration of equal to or less than 10.sup.14 cm.sup.3; a body zone arranged in the active region and having dopants of a second conductivity type complementary to the first conductivity type and isolating the drift layer from the first load terminal; a guard zone arranged in the junction termination region and having dopants of the second conductivity type and being configured to extend a depletion region formed by a transition between the drift layer and the body zone; a field stop zone arranged adjacent to the guard zone, the field stop zone having dopants of the first conductivity type at a field stop zone dopant concentration that is higher than the drift layer dopant concentration by a factor of at least 2; a low doped zone arranged adjacent to the field stop zone, the low doped zone having dopants of the first conductivity type at a dopant concentration that is lower than the drift layer dopant concentration by a factor of at least 1.5, wherein the body zone, the guard zone, the field stop zone and the low doped zone are arranged in the semiconductor body such that they exhibit a common depth range (DR) of at least 1 m along a vertical extension direction (Z).

In a general aspect, a high-voltage metal-oxide-semiconductor (HVMOS) device can include comprising a first gate dielectric layer disposed on a channel region of the HVMOS device and a second gate dielectric layer disposed on at least a portion of a drift region of the HVMOS device. The drift region can be disposed laterally adjacent to the channel region. The second gate dielectric layer can have a thickness that is greater than a thickness of the first gate dielectric layer.

A high voltage semiconductor device includes a semiconductor substrate, a first drift region, a gate structure, a first sub gate structure, a first spacer structure, a second spacer structure, and a first insulation structure. The first drift region is disposed in the semiconductor substrate. The gate structure is disposed on the semiconductor substrate and separated from the first sub gate structure. The first sub gate structure and the first insulation structure are disposed on the first drift region. The first spacer structure is disposed on a sidewall of the gate structure. The second spacer structure is disposed on a sidewall of the first sub gate structure. At least a part of the first insulation structure is located between the first spacer structure and the second spacer structure. The first insulation structure is directly connected with the first drift region located between the first spacer structure and the second spacer structure.

A method of making a semiconductor device includes forming a first polysilicon structure over a first portion of a substrate. The method further includes forming a first spacer on a sidewall of the first polysilicon structure, wherein the first spacer has a concave corner region between an upper portion and a lower portion. The method further includes forming a protective layer covering an entirety of the first spacer and the first polysilicon structure, wherein the protective layer has a first thickness over the concave corner region and a second thickness over the first polysilicon structure, and a difference between the first thickness and the second thickness is at most 10% of the second thickness.

A method includes: forming a barrier layer in a substrate; depositing a first dielectric layer over the substrate; forming a patterned mask layer over the first dielectric layer; patterning the first dielectric layer into a first sublayer of a gate dielectric layer; converting at least part of the patterned mask layer into a second sublayer of the gate dielectric layer; depositing a second dielectric layer adjacent to the first and second sublayers to serve as a third sublayer of the gate dielectric layer; and depositing a gate electrode over the gate dielectric layer.

A semiconductor structure includes: a semiconductor substrate; a gate dielectric layer over the semiconductor substrate; and a gate electrode over the gate dielectric layer. The gate dielectric layer includes a first portion and a second portion thinner than the first portion, wherein the gate electrode is over the first portion and the second portion, and the first portion includes a third portion including nitrogen and enclosed by the first portion.