| 摘要 |
PURPOSE:To form guard rings in narrow width and to permit high integration by performing oxidating isolation after forming diffusion layers serving as guard rings at concave sections provided for the oxidating isolation in an LSI incorporated a Schottky barrier diode (SBD). CONSTITUTION:An SiO2 film 4 and an Si3N4 film 5 are stacked on an N<-> epitaxial layer 3 to form concave sections 6 by using the film 5 as a mask and shallow P type diffusion regions 7 are uniformly formed in the concave sections 6 and the depth of the regions 7 prescribes guard rings for an SBD. Next, the film 5 is used as a mask by keeping the film 5 intact and Si in the concave sections 6 is selectively oxided to grow SiO2 layers reaching as far as a substrate 1 and isoplanar structure is formed. Next, high concentration N<+> regions 2a, 2b for taking out electrodes are formed by selectively etching the film 4, furthermore, P type and N<+> type regions 9, 10 are formed at the part forming an N-P-N bipolar transistor and electrodes 11-15 are formed by patterning Al to compose an SBD with guard rings. |
