A NOVEL STI SCHEME TO PREVENT FOX RECESS DURING PRE-CMP HF DIP

摘要

ABSTRACTA NOVEL STI SCHEME TO PREVENT FOX RECESS DURING PRE-CMP HF DIPA new method is provided for the creation of STI regions.STI trenches are created in the surface of a substrate followingconventional processing. A layer of STI oxide is deposited and,using an exposure mask that is a reverse mask of the mask that isused to create the STI pattern, impurity implants are performedinto the surface of the deposited layer of STI oxide. In view ofthese processing conditions, the layer of STI oxide overlying thepatterned layer of etch stop material is exposed to the impurityimplants. This exposure alters the etch characteristics of thedeposited layer of STI oxide where this STI oxide overlies thepatterned layer of etch stop material. The etch rate of theimpurity exposed STI oxide is increased by the impurityimplantation, resulting in an etch overlying the patterned etchstop layer that proceeds considerably faster than the etch of theSTI oxide that is deposited overlying the created STI trenches.With the significantly faster etch of the STI oxide where thisoxide has been exposed to impurity implantation, the STI oxideremoval can be equalized between the STI oxide that overlies thepatterned etch stop layer and the oxide that has been depositedover the STI trenches.FIGURE 9