| 摘要 |
PURPOSE:To enable a large current semiconductor switch and control circuit thereof to be formed in one chip and less man-hours by a method wherein deep N type diffused layers are selectively formed in a P type epitaxial layer to form a DSAMOS large current switch and P-ch MOS in the N type layers. CONSTITUTION:A high concentration buried layer 12 with the second conductivity is selectively formed in a part of a semiconductor substrate 11 with the first conductivity and then an epitaxial layer 13 with the second conductivity is formed on overall surface of the semiconductor substrate 11. Next, diffused layers 15, 14 are formed selectively diffusing in the parts immediately above said buried layer 12 on the surface of epitaxial layer 13 and excluding the buried layer 12 until reaching the buried layer 12 and the semiconductor substrate 11. Later, a large current switch element is formed in the diffused layer 14 excluding said buried layer 12 while semiconductor element electrically isolated from said large current switch element are formed in the diffused layer 15 including the buried layer 12 as well as the semiconductor substrate 13. |
