Patent ID: 6867457

Claim:
A semiconductor device having a plurality of electrothermal conversion elements and a plurality of switching elements for flowing current through the electrothermal conversion elements, respectively formed on a semiconductor substrate of a first conductivity type, wherein: each of said switching elements is an insulated gate field effect transistor comprising: a first semiconductor region of a second conductivity type opposite to the first conductivity type, said first semiconductor region being formed on a principal surface of said semiconductor substrate; a second semiconductor region of the first conductivity type for providing a channel region, said second semiconductor region being formed adjacent to said first semiconductor region; a source region of the second conductivity type formed in a surface layer of said second semiconductor region; a drain region of the second conductivity type formed in a surface layer of said first semiconductor region; and a gate electrode formed on a gate insulating film on the channel region; and a resistivity of said semiconductor substrate is 5 to 18 Ωcm, and said first semiconductor region has a depth of 2.0 to 2.2 μm along a depth direction of said semiconductor substrate and an impurity concentration of 1×10 14 to 1×10 18 /cm 3 .