Lateral double-diffused mos transistor having multiple current paths for high breakdown voltage and low on-resistance

Abstract

A lateral double-diffused MOS (LDMOS) transistor is provided. The LDMOS transistor includes a semiconductor substrateformed of a material having p-conductivity type impurities, a drift region formed of a material having n-conductivity type impurities on the semiconductor substrate, a first buried layerof p-type material and a second buried layerformed of n-type material. Layersandare arranged at the boundary between the semiconductor substrate and the drift region. A first well regionof p-type material contacts the first buried layern-type in a first portionof the drift region. A first source regionconductivity in a predetermined upper region of the first well region, a drain region formed of a material having second conductivity type impurities in a predetermined region of the drift region, the drain region being spaced a predetermined gap apart from the first well region, a third buried layer formed of a material having first conductivity type impurities in a second region of the drift region, the third buried layer being overlapped with a part of an upper portion of the first buried layer, a second well region formed of a material having first conductivity type impurities in the second region of the drift region, the second well region being overlapped with the third buried layer, a second source region formed of a material having second conductivity type impurities in a predetermined upper region of the second well region, a gate insulating layer formed in a first channel region inside the first well region and in a second channel region inside the second well region, a gate electrode formed on the gate insulating layer, a source electrode formed to be electrically connected to the first source region and the second source region, and a drain electrode formed to be electrically connected to the drain region.