초록 ▼

A method is disclosed for planarizing interlevel dielectric layers in semiconductor wafers extremely smoothly. The key aspect of the disclosure is a buried stop layer that is ion implanted into the interlevel layer. It is shown that the stop layer can be formed at precise depths from the surface of

A method is disclosed for planarizing interlevel dielectric layers in semiconductor wafers extremely smoothly. The key aspect of the disclosure is a buried stop layer that is ion implanted into the interlevel layer. It is shown that the stop layer can be formed at precise depths from the surface of the oxide layer and in a mostly planar surface. When the oxide layer with the buried stop layer is chemical/mechanically polished in the conventional manner, polishing stops at the stop layer yielding also a planar surface. The planarity of the polished surface can be extremely refined by first forming an extremely refined stop layer. The latter is accomplished by first planarizing the surface of the oxide layer in a number of ways before implanting the stop layer. It is further shown that when nitrogen atoms are used as the species for implanting, the resulting stop layer acquires a hardness very favorable for being differentiated from the softer oxide layer. Such abrupt difference in hardness provides a very precise polishing endpoint. At the same time, overpolishing of the interlevel layer is avoided.

대표청구항 ▼

A method of forming a polish stop layer for chemical/mechanical polishing (CMP) of semiconductor wafers comprising the steps of: providing a wiring layer comprising aluminum on said wafer; providing an oxide layer on said wiring layer; ion implanting atoms in said oxide layer to form a polish stop l

A method of forming a polish stop layer for chemical/mechanical polishing (CMP) of semiconductor wafers comprising the steps of: providing a wiring layer comprising aluminum on said wafer; providing an oxide layer on said wiring layer; ion implanting atoms in said oxide layer to form a polish stop layer; and chemical/mechanical polishing (CMP) said oxide layer.