Latch-Up Free CMOS Structure
Original Publication Date: 1986-Feb-01
Included in the Prior Art Database: 2005-Mar-08
This article relates generally to integrated circuit fabrication and, more particularly, to a construction technique for preventing active device latch-up. Full dielectric isolation of active CMOS devices forestalls conductive latch-up and is achieved by using oxide as a mask for growing selective epitaxy and oxygen ion implantation to produce an insulator. In Fig. 1, a layer 1 of oxide is grown on a p or n type silicon substrate 2 and selectively removed via photoresist patterning to expose the substrate. A thin epitaxial layer 3, indicated by dashed lines, is selectively grown on the exposed silicon using oxide 1 as a mask. Oxygen is implanted into the epitaxial layer 3 to form a buried oxide layer 4 approximately 3000 thick and about 2000 ˜ down from the surface of the layer 3.