Structures Electrically Connecting Aluminum and Copper Interconnections and Methods of Forming the Same

Abstract

A structure and formation method for electrically connecting aluminum and copper interconnections stabilize a semiconductor metallization process using an inner shape electrically connecting the aluminum and copper interconnections. To this end, a copper interconnection is disposed on a semiconductor substrate. An interconnection induction layer and an interconnection insertion layer are sequentially formed on the copper interconnection to have a contact hole exposing the copper interconnection. An upper diameter of the contact hole may be formed to be larger than a lower diameter thereof. A barrier layer and an aluminum interconnection are filled in the contact hole. The aluminum interconnection is formed not to directly contact the copper interconnection through the contact hole.

1 . A structure electrically connecting aluminum and copper interconnections, comprising.
 an interconnection induction layer and an interconnection insertion layer defining a contact hole, having a step difference on a sidewall of the contact hole such that a width of the contact hole narrows from an upper part of the contact hole to a lower part thereof and formed of nitride and oxide respectively.   
   
   
       2 . The structure according to  claim 1 , wherein the nitride comprises silicon nitride or a material having at least one of metal and non-metal atoms in a lattice of the silicon nitride. 
   
   
       3 . The structure according to  claim 1 , wherein the oxide comprises silicon oxide and a material having at least one of metal and non-metal atoms in a lattice of the silicon oxide. 
   
   
       4 . A structure electrically connecting aluminum and copper interconnections, comprising:
 an interconnection induction layer, an interconnection filling layer and an interconnection insertion layer defining a contact hole, having respective step differences therebetween on a sidewall of the contact hole such that a width of the contact hole narrows from an upper part of the contact hole to a lower part thereof, and formed of first nitride, second nitride and oxide, respectively.   
   
   
       5 . The structure according to  claim 4 , wherein the first and second nitrides comprise a nitrogen-rich material and a silicon-rich material, respectively. 
   
   
       6 . The structure according to  claim 4 , wherein the first and second nitrides comprise a silicon-rich material and a nitrogen-rich material, respectively. 
   
   
       7 . The structure according to  claim 4 , wherein the oxide comprises silicon oxide or a material having at least one of metal and non-metal atoms in a lattice of the silicon oxide. 
   
   
       8 . A structure electrically connecting aluminum and copper interconnections, comprising:
 an interconnection induction layer and an interconnection insertion layer defining a contact hole, having a first step difference on a sidewall of the contact hole such that a width of the contact hole narrows from an upper part of the contact hole to a lower part thereof, and formed of first nitride and oxide, respectively; and   a contact spacer disposed on the sidewalls of the contact hole to have a second step difference corresponding to the first step difference of the sidewall and formed of second nitride.   
   
   
       9 . The structure according to  claim 8 , wherein the first and second nitrides comprise a material having silicon and nitrogen in a same ratio. 
   
   
       10 . The structure according to  claim 8 , wherein the first and second nitrides comprise a silicon-rich material and a nitrogen-rich material, respectively. 
   
   
       11 . The structure according to  claim 8 , wherein the first and second nitrides comprise a nitrogen-rich material and a silicon-rich material, respectively. 
   
   
       12 . A method of forming a structure electrically connecting aluminum and copper interconnections, the method comprising:
 preparing an interconnection induction layer formed of nitride;   forming an interconnection insertion layer formed of oxide on the interconnection induction layer;   forming a first hole sequentially penetrating the interconnection insertion layer and the interconnection induction layer; and   forming a second hole in the interconnection insertion layer by enlarging the first hole to partially expose a top surface of the interconnection induction layer, the first and second holes forming one contact hole including the first and second holes.   
   
   
       13 . The method according to  claim 12 ., wherein forming the first hole comprises:
 forming a photoresist layer having an opening on the interconnection insertion layer;   etching, sequentially, the interconnection insertion layer and the interconnection induction layer using the photoresist layer as an etching mask, and   removing the photoresist layer from the interconnection insertion layer.   
   
   
       14 . The method according to  claim 13 , wherein forming the second hole comprises:
 etching the interconnection insertion layer through the first hole using the interconnection induction layer as an etch buffer layer,   wherein the etching process is performed using one of wet and dry etchants.   
   
   
       15 . The method according to  claim 12 , wherein the oxide is formed of silicon oxide or a material having at least one of metal and non-metal atoms in a lattice of the silicon oxide. 
   
   
       16 . The method according to  claim 12 , wherein the nitride is formed of silicon nitride or a material having at least one of metal and non-metal atoms in a lattice of the silicon nitride. 
   
   
       17 . A method of forming a structure electrically connecting aluminum and copper interconnections, the method comprising:
 preparing an interconnection induction layer formed of first nitride;   forming, sequentially, an interconnection filling layer formed of second nitride and an interconnection insertion layer formed of oxide on the interconnection induction layer;   forming a first hole sequentially penetrating the interconnection insertion layer, the interconnection filling layer and the interconnection induction layer;   forming a second hole in the interconnection insertion layer and the interconnection filling layer by enlarging the first hole to partially expose a top surface of the interconnection induction layer; and   forming a third hole in the interconnection insertion layer by enlarging the second hole to partially expose a top surface of the interconnection filling layer, the first to third holes forming one contact hole.   
   
   
       18 . The method according to  claim 17 , wherein forming the first hole comprises:
 forming a photoresist layer having an opening on the interconnection insertion layer;   etching, sequentially, the interconnection insertion layer, the interconnection filling layer and the interconnection induction layer through the opening using the photoresist layer as an etching mask; and   removing the photoresist layer from the interconnection insertion layer.   
   
   
       19 . The method according to  claim 18 , wherein forming the second hole comprises:
 etching the interconnection insertion layer and the interconnection filling layer through the first hole using the interconnection induction layer as an etch buffer layer,   wherein the etching process is performed using one of wet and dry etchants.   
   
   
       20 . The method according to  claim 19 , wherein forming the third hole comprises:
 etching the interconnection insertion layer through the second hole using the interconnection filling layer and the interconnection induction layer as etch buffer layers,   wherein the etching process is performed using one of wet and dry etchants.   
   
   
       21 . The method according to  claim 17 , wherein the first and second nitride layers are formed of a silicon-rich material and a nitrogen-rich material, respectively. 
   
   
       22 . The method according to  claim 17 , wherein the first and second nitride layers are formed of a nitrogen-rich material and a silicon-rich material, respectively. 
   
   
       23 . The method according to  claim 17 ., wherein the oxide is formed of silicon oxide or a material having at least one of metal and non-metal atoms in a lattice of the silicon oxide. 
   
   
       24 . A method of forming a structure electrically connecting aluminum and copper interconnections, the method comprising:
 preparing an interconnection induction layer formed of first nitride;   forming an interconnection insertion layer formed of oxide on the interconnection induction layer;   forming a first hole sequentially penetrating the interconnection insertion layer and the interconnection induction layer;   forming a second hole in the interconnection insertion layer by enlarging the first hole to partially expose a top surface of the interconnection induction layer, the first and second holes forming one contact hole; and   forming a contact spacer covering a sidewall of the one contact hole and formed of second nitride.   
   
   
       25 . The method according to  claim 24 , wherein forming the first hole comprises:
 forming a photoresist layer having an opening on the interconnection insertion layer;   etching, sequentially,, the interconnection insertion layer and the interconnection induction layer using the photoresist layer as an etching mask; and   removing the photoresist layer from the interconnection insertion layer.   
   
   
       26 . The method according to  claim 25 , wherein forming the second hole comprises:
 etching the interconnection insertion layer through the first hole using the interconnection induction layer as an etch buffer layer,   wherein the etching process is performed using one of wet and dry etchants.   
   
   
       27 . The method according to  claim 24 , wherein the first and second nitrides are formed of a material having silicon and nitrogen in the same ratio. 
   
   
       28 . The method according to  claim 24 , wherein the first and second nitrides are formed of nitrogen-rich nitride and silicon-rich nitride, respectively. 
   
   
       29 . The method according to  claim 24 , wherein the first and second nitrides are formed of silicon-rich nitride and nitrogen-rich nitride, respectively. 
   
   
       30 . The method according to  claim 24 ., wherein the oxide is formed of silicon oxide or a material having at least one of metal and non-metal atoms in a lattice of the silicon oxide.