| 摘要 |
PURPOSE:To obtain a constant voltage output circuit suited to a monolithic IC by producing the reference voltage according to the difference of threshold voltage between the 1st and 2nd insulated gate type field effect transistors. CONSTITUTION:The p<+> type areas 4 and 5 serving as the source and the drain of an MISFET are formed on an n type semiconductor substrate 1. A gate insulated film 2 is formed on the surface of the substrate 1 between both areas 4 and 5, and a polysilicon layer is formed on the film 2. An impurity (n type) of the same conduction type as the substrate 1 is mixed into the polysilicon layer which forms a gate 6' of an MISFETQ1. While an impurity (p type) adverse to the substrate 1 is mixed into the polysilicon layer forming a gate 6 of an MISFETQ2. The threshold values of both FETs Q1 and Q2 are obtained by equations respectively, and the voltage difference between both threshold values is equal to a difference (phiMp-phiMn) of the work function. This difference can be defined as the voltage corresponding to the energy gap of the silicon. |
