Patent ID: 9117797
Filing Date: 2015-08-25
Classification: H01L

Abstract:
1. A high-voltage semiconductor device comprising: a second conductivity type well region which is formed on a first conductivity type semiconductor substrate and includes a logic circuit formation region and a withstand voltage region surrounding the logic circuit formation region; a first conductivity type well region which is formed on the semiconductor substrate so as to surround the withstand voltage region; a transistor which includes a second conductivity type drain region selectively formed in a surface layer of the second conductivity type well region between the withstand voltage region and the logic circuit formation region and having a higher concentration of impurities than the withstand voltage region, and a second conductivity type source region selectively formed in the surface layer of the second conductivity type well region, and which uses the withstand voltage region between the drain region and the source region as a drift region and uses the first conductivity type well region as a base region; an opening region which is provided locally in the second conductivity type well region between the drain region and the logic circuit formation region so as to prevent the second conductivity type well region from lying all over the opening region in a depth direction; and a conductive path which electrically connects the drain region with a logic circuit in the logic circuit formation region; the high-voltage semiconductor device further comprising: a shield layer which is formed on a first insulating layer formed on a surface of the opening region and which is connected to a negative electrode side of a power supply connected to the logic circuit in the logic circuit formation region.