IMPROVED NARROW TRENCH PROFILE USING A COMPOSITE SPACER PROCESS
Original Publication Date: 1996-Aug-01
Included in the Prior Art Database: 2002-Apr-24
An advanced silicon integrated circuit process utilizes a sub-micron trench extending through a layer of polysilicon over single crystal silicon. The profile and depth of this narrow trench impact the characteristics of the device and therefore must be well controlled. Two approaches to define this trench are described and illustrated below. The Composite Spacer Process represents a significant improvement over the Niide Spacer Process and has been shown to reduce the overall variability ofthe trench. cut region may be difficult to refill with some mate- rials (such as furnace TEOS) during subsequent processing steps without leaving a void.