Lateral power semiconductor device for high frequency power conversion system, has isolation layer formed over substrate for reducing minority carrier storage in substrate

A method of manufacturing a lateral power semiconductor device, consisting of:

• forming a substrate;
• forming an oxide layer over the substrate for reducing minority carrier storage in the substrate;
• forming a silicon layer directly on the oxide layer;
• forming a well region in the silicon layer;
• forming a source region, drain region with a lightly doped drain (LDD) region, gate region, and channel region of the lateral power semiconductor device in the well region, the channel region being disposed below the gate region between the source region and LDD drain region, the source region and drain region with LDD drain region having a first conductivity type, the channel region and well region having a second conductivity type;
• forming a first region having the second conductivity type on a surface of the lateral power semiconductor device adjacent to the source region, wherein a body diode is formed between the first region and drain region;
• and
• forming a second region having the second conductivity type in the well region below the source region and first region;
• wherein the oxide layer confines the minority carrier charge from the body diode to a depth of less than 20 micrometers from the surface of the lateral power semiconductor device.