METHOD OF FACILITATING THREE-DIMENSIONAL DEVICE LAYOUT

摘要

PROBLEM TO BE SOLVED: A device layout has a device structure including a first device and a second device formed thereon, and an active region of the second region is located inside the upper surface so as to facilitate a three-dimensional device layout. SOLUTION: For example, a highly doped N<+> polylayer is next formed on the surface. This polylayer is planarized up to an upper surface of a gate 895 to form a bit-line contact area 110. An MO dielectric layer is layed to expose the contact area 110. A metal layer 150 is next deposited so as to fill an contact opening 120. This metal layer 150 is etched for forming a bit-line conductor. The capacity of spatially positioning a device on a trench allows a more effective three-dimensional layout. As a result, the density of a device for a prescribed area can be increased.