Phase change memory device and fabrication method thereof

Abstract

A phase change memory device is provided that includes a switching device, a bottom electrode contact in contact with the switching device and a porous spacer formed on the bottom electrode contact.

1 . A phase change memory device, comprising:
 a switching device;   a bottom electrode contact in contact with the switching device; and   a porous spacer formed on a portion of the bottom electrode contact.   
     
     
         2 . The phase change memory device of  claim 1 , wherein the porous spacer is comprised of a germanium compound. 
     
     
         3 . The phase change memory device of  claim 2 , wherein the germanium compound comprises silicon-germanium. 
     
     
         4 . The phase change memory device of  claim 2 , wherein the germanium compound comprises silicon-germanium-nitride. 
     
     
         5 . A method of manufacturing a phase change memory device, comprising the steps of:
 forming a bottom electrode contact hole to expose a switching device on a semiconductor substrate;   forming an insulating layer on a resultant structure of the semiconductor substrate including the bottom electrode contact hole by using an insulating compound having materials of different atomic sizes; and   forming an insulating spacer within the bottom electrode contact hole by selectively etching the insulating layer.   
     
     
         6 . The method of  claim 5 , wherein the step of forming an insulating layer comprises repeatedly depositing a plurality of insulating materials having different atomic sizes at least one or more times in a pre-arranged order. 
     
     
         7 . The method of  claim 5 , wherein the insulating compound comprises a germanium compound. 
     
     
         8 . The method of  claim 7 , wherein the germanium compound comprises silicon-germanium. 
     
     
         9 . The method of  claim 8 , wherein the step of forming an insulating layer comprises repeatedly depositing a silicon layer and a germanium layer at least one or more times in a pre-arranged order. 
     
     
         10 . The method of  claim 8 , wherein the insulating layer is a Ge-rich insulating layer. 
     
     
         11 . The method of  claim 8 , wherein the insulating layer is a Si-rich insulating layer. 
     
     
         12 . The method of  claim 7 , wherein the germanium compound comprises silicon-germanium-nitride. 
     
     
         13 . The method of  claim 12 , wherein the step of forming an insulating layer comprises repeatedly depositing each of a silicon layer, a germanium layer and a nitride layer at least one or more time in a pre-arranged order. 
     
     
         14 . The method of  claim 13 , wherein after forming the silicon layer, the germanium layer and the nitride layer, further carrying out purge processes, respectively,
 wherein a purge time of a purge process carried out after forming the nitride layer is two to three times longer than a purge time of a purge process carried out after forming the silicon layer and the germanium layer.   
     
     
         15 . The method of  claim 12 , wherein the insulating layer comprises a Ge-rich insulating layer. 
     
     
         16 . The method of  claim 12 , wherein the insulating layer comprises a Si-rich insulating layer. 
     
     
         17 . The method of  claim 12 , wherein the step of forming an insulating layer comprises forming a Ge-rich insulating layer by sequentially depositing a silicon layer, a germanium layer and a nitride layer at least one or more times. 
     
     
         18 . The method of  claim 12 , wherein the step of forming an insulating layer comprises forming a Si-rich insulating layer by sequentially depositing a silicon layer, a germanium layer and a nitride layer at least one or more times. 
     
     
         19 . The method of  claim 12 , wherein the step of forming an insulating layer comprises forming a Ge-rich insulating layer by sequentially depositing a silicon layer, a nitride layer and a germanium layer at least one or more times. 
     
     
         20 . The method of  claim 12 , wherein the step of forming an insulating layer comprises forming a Si-rich insulating layer by sequentially depositing a silicon layer, a nitride layer and a germanium layer at least one or more times. 
     
     
         21 . The method of  claim 5 , wherein the step of forming an insulating layer comprises depositing a plurality of insulating materials having different atomic sizes by using a chemical vapor deposition method. 
     
     
         22 . A method of manufacturing a phase change memory device, comprising the steps of:
 forming a switching device on a semiconductor substrate;   forming a bottom electrode contact hole to an upper portion of the switching device; and   forming a porous spacer on a portion of the bottom electrode contact hole.   
     
     
         23 . The method of  claim 22 , wherein the step of forming a porous spacer comprises;
 forming a porous insulating layer on a resultant structure of the semiconductor substrate including the bottom electrode contact hole; and   space-etching the porous insulating layer.   
     
     
         24 . The method of  claim 23 , wherein the porous insulating layer is formed by using a germanium compound. 
     
     
         25 . The method of  claim 24 , wherein the germanium compound comprises silicon-germanium. 
     
     
         26 . The method of  claim 25 , wherein the step of forming a porous insulating layer comprises sequentially depositing a silicon layer and a germanium layer at least one or more times. 
     
     
         27 . The method of  claim 26 , wherein the porous insulating layer comprises a Ge-rich insulating layer. 
     
     
         28 . The method of  claim 26 , wherein the insulating porous layer comprises a Si-rich insulating layer. 
     
     
         29 . The method of  claim 24 , wherein the germanium compound comprises silicon-germanium-nitride. 
     
     
         30 . The method of  claim 29 , wherein the porous insulating layer comprises a Ge-rich insulating layer. 
     
     
         31 . The method of  claim 29 , wherein the insulating layer comprises a Si-rich insulating layer. 
     
     
         32 . The method of  claim 29 , wherein after forming the silicon layer, the germanium layer and the nitride layer, further comprising carrying out purge processes respectively,
 wherein a purge time of a purge process carried out after forming the nitride layer is two to three times longer than a purge time of a purge process carried out after the silicon layer and the germanium layer.   
     
     
         33 . The method of  claim 23 , wherein the step of forming a porous insulating layer comprises depositing a plurality of insulating materials having different atomic sizes by a chemical vapor deposition method.