High voltage metal oxide semiconductor device and manufacturing method thereof

A manufacturing method of a high voltage metal oxide semiconductor (MOS) device, comprising:

• providing a semiconductor substrate having a top surface and a bottom surface opposite to the top surface in a vertical direction;
• forming a first drift region with a first conductive type in the semiconductor substrate, wherein the first drift region is located under the top surface and contacts the top surface in the vertical direction;
• forming plural second drift regions with the second conductive type in the first drift region, wherein the plural second drift regions are located under the top surface in the vertical direction;
• forming a gate on the top surface;
• forming a body region with a second conductive type in the first drift region, wherein the body region is located under the top surface and contacts the top surface in the vertical direction;
• wherein in the vertical direction, a portion of the gate is stacked above a portion of the body region, and another portion of the gate is stacked above a portion of each of the second drift region;
• forming plural source regions with the first conductive type in the body region, wherein the plural source regions is are located under the top surface and contact the top surface in the vertical direction, and neighbor the gate in a lateral direction;
• forming a drain with the first conductive type in the first drift region, wherein the drain is located under the top surface and contacts the top surface in the vertical direction, and is separated from the plural source regions by the body region and the first drift region in the lateral direction, and is separated from the body region by the first drift region in the lateral direction;
• and
• forming plural body contact regions with the second conductive type in the body region, wherein the plural body contact regions are located under the top surface and contact the top surface in the vertical direction;
• wherein the plural second drift regions are separately located along a width direction such that any two neighboring second drift regions do not contact each other in the width direction, wherein each of the second drift regions contacts the body region in the lateral direction, and each of the second drift regions is separated from the drain by the first drift region, and each of the second drift regions is separated from the source by the body region;
• wherein the plural source regions are separately located along the width direction and any two neighboring source regions are separated from each other by one of the body contact regions in the width direction, and wherein the plural body contact regions are separately located along the width direction and any two neighboring body contact regions are separated from each other by one of the source regions in the width direction, and a portion of each of the body contact regions is located right below the gate;
• wherein in the lateral direction, the plural second drift regions contact the plural body contact regions.