Semiconductor device and manufacturing method thereof for realizing high packaging density

Abstract

In a semiconductor device in which an interlayer insulating layer is formed of a low density material (porous silica etc.) and a hole or a trench is formed in the interlayer insulating layer by processing the interlayer insulating layer and an electrically conductive material is coated on the processed surface of the hole or trench for establishing electrical connection, the density of part of the interlayer insulating layer near the processed surface of the hole or trench is increased in comparison with other parts of the interlayer insulating layer. The densification process is conducted by the elimination of microvoids near the processed surface, for example. The densification or the microvoid elimination can be conducted by use of ammonia water, vapor of ammonia water, ammonia plasma treatment, etc. By the densification process, coating of the electrically conductive material (Cu etc.) on the processed surface of the hole or trench can be conducted successfully in the following steps and thereby the manufacture of semiconductor devices of stable performance can be realized. By the use of the low density material for the interlayer insulating layer, the space between wires in the semiconductor device can be made smaller and thereby miniaturization and speeding up of semiconductor device can be attained.

What is claimed is:  
     
         1 . A semiconductor device in which an interlayer insulating layer is formed of a low density material and a hole or a trench is formed in the interlayer insulating layer by processing the interlayer insulating layer and an electrically conductive material is coated on the processed surface of the hole or trench for establishing electrical connection, wherein: 
 the density of part of the interlayer insulating layer near the processed surface of the hole or trench is increased in comparison with other parts of the interlayer insulating layer.    
     
     
         2 . A semiconductor device as claimed in  claim 1 , wherein the low density material is a porous material.  
     
     
         3 . A semiconductor device as claimed in  claim 2 , wherein the porous material is porous silica.  
     
     
         4 . A semiconductor device as claimed in  claim 3 , wherein the porous silica at least includes Si—H bonds and/or Si—CH3 bonds.  
     
     
         5 . A semiconductor device in which an interlayer insulating layer is formed of a low density material and a hole or a trench is formed in the interlayer insulating layer by processing the interlayer insulating layer and an electrically conductive material is coated on the processed surface of the hole or trench for establishing electrical connection, wherein: 
 microvoids are removed in part of the interlayer insulating layer near the processed surface of the hole or trench.    
     
     
         6 . A semiconductor device as claimed in  claim 5 , wherein the low density material is a porous material.  
     
     
         7 . A semiconductor device as claimed in  claim 6 , wherein the porous material is porous silica.  
     
     
         8 . A semiconductor device as claimed in  claim 7 , wherein the porous silica at least includes Si—H bonds and/or Si—CH3 bonds.  
     
     
         9 . A manufacturing method of a semiconductor device having an interlayer insulating layer which is formed of a low density material, comprising the steps of: 
 a processing step in which the interlayer insulating layer is processed and thereby a hole or a trench is formed in the interlayer insulating layer;    a densification step in which the density of part of the interlayer insulating layer near the processed surface of the hole or trench is increased; and    a conductive material coating step in which an electrically conductive material is coated on the processed surface of the hole or trench for establishing electrical connection.    
     
     
         10 . A manufacturing method of a semiconductor device as claimed in  claim 9 , further comprising: 
 a hydrophobic treatment step in which the processed surface of the hole or trench of the interlayer insulating layer is made hydrophobic.    
     
     
         11 . A manufacturing method of a semiconductor device as claimed in  claim 9 , wherein the densification step is conducted by use of ammonia water.  
     
     
         12 . A manufacturing method of a semiconductor device as claimed in  claim 9 , wherein the densification step is conducted by use of vapor of ammonia water.  
     
     
         13 . A manufacturing method of a semiconductor device as claimed in  claim 9 , wherein the densification step is conducted by means of ammonia plasma treatment.  
     
     
         14 . A manufacturing method of a semiconductor device as claimed in  claim 13 , wherein the ammonia plasma treatment is also used for removing photoresist which has been-used in the processing step for the formation of the hole or trench in the interlayer insulating layer.  
     
     
         15 . A manufacturing method of a semiconductor device as claimed in  claim 10 , wherein the hydrophobic treatment step is conducted by means of HMDS (hexamethyldisilazane) treatment.  
     
     
         16 . A manufacturing method of a semiconductor device as claimed in  claim 9 , wherein the low density material is a porous material.  
     
     
         17 . A manufacturing method of a semiconductor device as claimed in  claim 16 , wherein the porous material is porous silica.  
     
     
         18 . A manufacturing method of a semiconductor device as claimed in  claim 17 , wherein the porous silica at least includes Si—H bonds and/or Si—CH3 bonds.