| 摘要 |
PURPOSE:To enhance the accuracy of a reference voltage generator by introducing an n type impurity in high density to one of a pair of gate electrodes, and then introducing the equal amount of p type impurity to both the gate electrodes, thereby forming n type and p type gate electrodes. CONSTITUTION:After a gate film 27 is formed in the stage of forming a reference voltage generator utilizing the difference of the threshold values of a pair of p type MOSFETs, a polysilicon 29 is accumulated on the overall surface, a mask 30 is formed on a part of a substrate 21, and phosphorus ions are injected in a high density. After the respective gate electrodes are formed by photoetching, a mask 35 is covered on a P type well region, B ions are injected in the amount less than the phosphorus ions to convert the gate electrode 36 into a p type, and p<+> type diffused layers 37-39 are concurrently formed. Thereafter, a mask 40 is formed at the side of the substrate, phosphorus or arsenic is introduced, and diffused layers 41, 42 are formed. Thus, the equal amount of the B are introduced to a pair of the gates of the p type MOSFETs to allow the variations of the threshold values at the aging time to become in the same degree, resulting in the high accuracy of the semiconductor integrated circuit device. |
