| 摘要 |
PURPOSE:To increase the circuit density by forming the uni-conducting guard region between the reverse conducting IGFET and the uni-conducting IGFET provided within the same semiconductor substrate and then setting the guard region to the same potential as the substrate. CONSTITUTION:P-type well region 12 is formed by diffusion on N-type Si substrate 11, and then N<+>-type source and drain region 13 and 14 are provided within region 12. Thus, N-channel transistor Q1 is obtained. Then N+-type region 15 is formed enclosing transistor Q1 and with contact to substrate 11, and diffusion region 15' to be the guard ring is formed within region 15 to prevent the parasitic current. At the same time, P<+>-type source and drain regions 16 and 17 are formed by diffusion within substrate 11 and being adjacent to Q1 to obtain P-channel transistor Q2 along with N<+>-type guard ring 18 provided adjacently to region 16. Then gate G1 and G2 are provided to transistor Q1 and Q2 respectively, which are connected in common to obtain input IN. The common connection is also given to region 14 and 17 to obtain output OUT, and regions 15, 16 and 18 are connected in common to be then connected to power source VDD. |
