Phase change memory cell having a tapered microtrench

摘要

A phase change memory includes a cup-shaped heater element formed above a body. A tapered phase change region is formed on the cup-shaped heater element. The cup-shaped heater element is formed by depositing a stop layer of a first dielectric material over the body. A first sacrificial layer is deposited over the stop layer, the first sacrificial layer being of a second dielectric material that can be etched selectively with respect to the first dielectric material. An opening is etched in the first sacrificial layer and the stop layer. A heating layer is formed in the opening. The opening is filled with a filling material to obtain a structure having a cup-shaped heating region formed in the stop layer and excess portions extending over said stop layer. The excess portions by an etch selective with respect to the first dielectric material are removed.