Multilayer structure comprising a phase change material layer and method of producing the same

Abstract

A method of producing a multilayer structure is provided, wherein the method comprises forming a phase change material layer onto a substrate, forming a protective layer, forming a further layer on the protective layer, patterning the further layer in an first patterning step, patterning the protective layer and the phase change material layer by a second patterning step. In particular, the first patterning step may be an etching step using chemical etchants. Moreover, electrodes may be formed on the substrate before the phase change material layer is formed, e.g. the electrodes may be formed on one level, e.g. may form a planar structure and may not form a vertically structure.

1 . A multilayer structure comprising:
 a substrate;   a first electrode and a second electrode each including an interior portion and an exterior portion;   a first embedded conductor path connected to the first electrode and a second embedded conductor path connected to the second electrode, the first embedded conductor path and the second embedded conductor path being configured and arranged to carry electricity to the first electrode and the second electrode respectively; and   a phase change material layer extending laterally between the first electrode and the second electrode and covering the interior portions of the first electrode and the second electrode, the phase change material layer being patterned by a sputter dominated process, the patterning leaving the exterior portions of the first electrode and the second electrode exposed relative to the phase change material layer.   
     
     
         2 . The multilayer structure of  claim 1 , wherein the sputter dominated process is a highly anisotropic sputter dominated process. 
     
     
         3 . The multilayer structure of  claim 1 , further including an insulating protective layer covering the phase change material layer, wherein the insulating protective layer is patterned by the sputter dominated process. 
     
     
         4 . The multilayer structure of  claim 3 , wherein the phase change material and the insulating protective layer are patterned by the sputter dominated process in a single etching step. 
     
     
         5 . The multilayer structure of  claim 1 , wherein the first embedded conductor path and the second embedded conductor are formed from metal. 
     
     
         6 . The multilayer structure of  claim 1 , further including a passivating layer covering the phase change material layer and both the interior and exterior portions of the first electrode and the second electrode. 
     
     
         7 . The multilayer structure of  claim 1 , further including a first protective layer disposed on the phase change material, and a second protective layer disposed on the first protective layer. 
     
     
         8 . The multilayer structure of  claim 1 , wherein a portion of the substrate electrically isolates the first and second embedded conductor paths. 
     
     
         9 . The multilayer structure of  claim 8 , wherein a surface of the portion of the substrate separating the first and second embedded conductor paths is covered by the phase change material layer that extends laterally between the first electrode and the second electrode. 
     
     
         10 . A multilayer structure comprising:
 a substrate;   two electrodes arranged on the substrate;   a phase change material layer including a portion of the phase change material layer connecting the two electrodes; and   a protective layer arranged on the phase change layer, the protective layer including a first portion of the protective layer, located on the portion of the phase change material layer connecting the two electrodes and having a first non-zero thickness, and a second portion of the protective layer having a second thickness that is less than the first thickness by an amount that is sufficient to use the first portion of the protective layer as a mask to etch phase change material under the second portion of the protective layer in a single step of etching.   
     
     
         11 . The multilayer structure of  claim 10 , wherein the portion of the phase change material layer connecting the two electrodes is located on the substrate. 
     
     
         12 . The multilayer structure of  claim 10 , further including a photoresist layer covering the first portion of the protective layer. 
     
     
         13 . The multilayer structure of  claim 10 , further including two embedded conductive pathways, each pathway configured and arranged to carry electricity to a respective and different one of the two electrodes. 
     
     
         14 . The multilayer structure of  claim 10 , wherein the second portion of the protective layer is patterned using fluorine-based chemistry. 
     
     
         15 . The multilayer structure of  claim 10 , further including
 a bottom anti-reflective coating layer covering the first and second portions of the protective layer; and   a photoresist layer, deposed on the anti-reflective coating layer, covering the first portion of the protective layer.   
     
     
         16 . A multilayer structure comprising:
 a substrate;   two electrodes arranged on the substrate;   a phase change material layer including a portion of the phase change material layer connecting the two electrodes; and   a protective layer, arranged on the phase change material layer, that is patterned by a sputter dominated process.   
     
     
         17 . The multilayer structure of  claim 16 , further including two embedded conductive pathways, wherein a first of the two conductive pathways is connected to a first of the two electrodes, and a second of the two conductive pathways is connected to a second of the two electrodes. 
     
     
         18 . The multilayer structure of  claim 16 , wherein the protective layer an insulator. 
     
     
         19 . The multilayer structure of  claim 16 , wherein the two electrodes each include an interior portion and exterior portion. 
     
     
         20 . The multilayer structure of  claim 19 , wherein the portion of the phase change material layer connecting the two electrodes covers the interior portions of the two electrodes.