| 摘要 |
PURPOSE:To obtain an MOS transistor, gate threshold voltage thereof hardly varies, by forming a region of a conduction type reverse to first and second conduction type source and drain regions into the source or drain region when an IGFET is manufactured by forming the source and drain regions to a first conduction type semiconductor substrate at an interval and shaping a gate electrode between these source and drain regions through an insulating film. CONSTITUTION:The upper section of a semiconductor substrate 1 is coated with an insulating film 2, and an n<+> type region 3, a p type region 4, an n type region 5 and an n<+> type region 6 are formed on the insulating film while being mutually brought into contact. According to such constitution, the region 3 is used as an emitter, the region 4 as a base and the region 5 as a collector, thus constituting a bipolar-transistor. The region 3 is employed as a source, the region 5 as a channel and the region 6 as a drain and an MOS transistor is constituted, and a base electrode 9 is formed on the region 4 as a bipolar element and a gate electrode 8 through a gate insulating film 7 on the region 5 as an MOS element respectively. In the constitution, the built-in voltage of the bipolar element is selected in a value larger than the threshold voltage of the MOS element. |
