摘要 |
Techniques disclosed herein include increasing pattern density for creating high-resolution contact openings, slots, trenches, and other features. A conformal spacer is applied on a bi-layer or tri-layer mandrel (multi-layer) or other relief feature. The conformal spacer thus wraps around the mandrels and is also deposited on an underlying layer. A fill material is deposited to fill gaps or spaces between sidewall spacers. A CMP planarization step then removes substrate stack material down to a material interface of the bi-layer or tri-layer mandrel, with a middle or lower material of the mandrel being a CMP-stop material. This technique essentially cuts off or removes rounded features such as upper portions of sidewall spacers, thereby providing a spacer material with a planar top surface that can be uniformly etched and transferred to underlying layers. |