Abstract: A CMOS transistor is provided having a relatively high breakdown voltage. The CMOS transistor includes an N-type epitaxial layer on a P-type substrate. Between the substrate and epitaxial layer are a heavily doped N-type buried layer and a heavily doped P-type base layer. An N-type sink region is proximatethe edge of the NMOS region, and twin wells are in the area surrounded with the sink region. N+ source and drain regions are formed in respective wells. As the sink region is interposed between the drain and isolation regions, a breakdown occurs between the sink and isolation regions when a high voltage is applied. Twin wells are also formed in the PMOS region P+ source and drain regions are formed in respective wells. As the N-type well surrounds the source and bulk regions, a breakdown occurs between a buried region and the isolation region when a high voltage is applied.

Abstract: A CMOS transistor is provided having a relatively high breakdown voltage. The CMOS transistor includes an N-type epitaxial layer on a P-type substrate. Between the substrate and epitaxial layer are a heavily doped N-type buried layer and a heavily doped P-type base layer. An N-type sink region is proximate the edge of the NMOS region, and twin wells are in the area surrounded with the sink region. N+ source and drain regions are formed in respective wells. As the sink region is interposed between the drain and isolation regions, a breakdown occurs between the sink and isolation regions when a high voltage is applied. Twin wells are also formed in the PMOS region P+ source and drain regions are formed in respective wells. As the N-type well surrounds the source and bulk regions, a breakdown occurs between a buried region and the isolation region when a high voltage is applied.

Abstract: There are provided a double-diffused MOS (Metal Oxide Semiconductor) transistor and a fabricating method thereof. In the double-diffused MOS transistor, a buried layer of a first conductive type and an epitaxial layer of the first conductive type are sequentially formed on a semiconductor substrate, and a gate electrode is formed on the epitaxial layer of the first conductive type with interposition of a gate insulating film. Source and drain regions of the first conductive type are formed in the surface of the epitaxial layer of the first conductive type in self-alignment and non-self-alignment with the gate electrode, respectively. A body region of a second conductive type is formed in the surface of the epitaxial layer of the first conductive type to be surrounded by the source region of the first conductive type, and a bulk bias region of the second conductive type is formed in the body region of the second conductive type under the source region of the first conductive type.

Abstract: A semiconductor device, and a method of manufacturing the same, containing a high voltage DMOS transistor, a low voltage CMOS transistor, and a bipolar transistor in a single substrate. The steps include forming an isolation layer within the substrate in an isolation region between each of a DMOS region, a CMOS region, or a bipolar region. A first oxide layer of variable thickness is formed on the substrate, a thick second oxide layer is formed on the isolation layer, and a polysilicon layer is formed on both oxide layers. The polysilicon layer is patterned to form gate patterns on the first oxide layer and resistive patterns on the second oxide layer. The gate pattern is then doped but the resistive pattern is undoped. The thickness of the first oxide layer in the DMOS region is greater than the thickness of the first oxide layer in the CMOS region.