| 摘要 |
PURPOSE: To increase the no. of usable elements by forming all devices in a protective ring and forming diffusion resistors, diodes and transistors in the same sinker region or the protective ring. CONSTITUTION: Active devices, such as n-channel longitudinal DMOS transistors 12, are formed in an n-epitaxial layer 14 formed on a B-substrate 16. The transistor 12 forms a P-main body region 17 in the layer 14 and highly doped N+ source region in the region 17. Before forming the layer 14, a retarded diffusion dopant is added to the substrate 16, to form a highly doped N+ buried layer 22. An N+ sinker region 24 is formed by the ion implantation and diffusion of a high-speed diffusion dopant in the layer 14, extending from the buried layer 22 to the surface of the wafer. Thus a configurable integrated circuit, capable of forming diffusion resistances, diodes and transistors on the region 24 or protective annulus, is obtained. |
