| 摘要 |
PURPOSE:To reduce a current amplification factor by forming an epitaxial layer and a well layer on a semiconductor substrate, forming MOSFETs on the layers, and further forming a buried layer between the epitaxial layer and the substrate. CONSTITUTION:An N-type buried layer 22 is formed on a P-type silicon semiconductor substrate 21. Then, a P-well layer 24 is formed deeply in an epitaxial layer 23 to arrive at the substrate 21. Then, P-channel MOSFET is formed at N-channel MOSFET and the layer 23 in the layer 24. At this time the P- channel MOSFET is formed on the layer 22. Accordingly, the layer 22 is disposed between the substrate 21 at the lower portion of the P-channel MOSFET and the layer 23. |
