| 摘要 |
PURPOSE: A high-voltage semiconductor device having a high-voltage isolation region is provided to improve reliability, by forming an n-type epitaxial layer and an n¬+ type buried layer so that an impact ionization occurs in the n¬+ type buried layer earlier than in the surface area of the device. CONSTITUTION: An epitaxial layer(402) of the second conductivity type is formed on a semiconductor substrate(401) of the first conductivity type. The first diffusion region of the first conductivity type is formed in a high-voltage region and a high-voltage isolation region. A buried layer of the second conductivity type is formed in a high-voltage metal-oxide-semiconductor(MOS) transistor and between the substrate and the epitaxial layer. A source region of the first conductivity type is formed on the buried layer, separated from the buried layer. A drain region of the first conductivity type is formed on the epitaxial layer, separated from the source region. A resistor element transmits the signal from the high-voltage MOS transistor to a low-voltage region, formed in the low-voltage region. A gate insulation layer(410) is formed on the channel region formed on the epitaxial layer of the high-voltage MOS transistor. A gate electrode(411) is formed on the gate insulation layer. A source electrode(412) is in contact with the source region. A drain electrode(413) is connected to the resistor element through the high-voltage isolation region, and is in contact with the drain region. |
