Integrated circuit conductive contact structures including grooves and fabrication methods thereof

Abstract

An integrated circuit includes a substrate and a first insulating layer on the substrate that includes a first hole including a floor and a sidewall. A first conductive contact extends conformally on the sidewall and floor to define a groove in the first hole. A second insulating layer is provided on the first insulating layer and includes a second hole that exposes the groove. A second conductive contact is provided in the second hole and in the groove. These integrated circuits are fabricated by forming a first insulating layer on a substrate that includes a first hole including a floor and a sidewall. A first conductive contact is conformally formed on the sidewall and floor to define a groove in the first hole. A second insulating layer is formed on the first insulating layer and includes a second hole that exposes the groove. A second conductive contact is formed in the second hole and in the groove.

What is claimed is:  
     
         1 . An integrated circuit comprising: 
 a substrate;    a first insulating layer on the substrate that includes therein a first hole passing therethrough that includes a floor adjacent the substrate and a sidewall;    a first conductive contact that extends conformally on the sidewall and floor to define a groove in the first hole;    a second insulating layer on the first insulating layer remote from the substrate that includes therein a second hole passing therethrough that exposes the groove; and    a second conductive contact in the second hole and in the groove.    
     
     
         2 . An integrated circuit according to  claim 1  wherein the floor is directly on the substrate.  
     
     
         3 . An integrated circuit according to  claim 1  wherein the second conductive contact fills the second hole and the groove.  
     
     
         4 . An integrated circuit according to  claim 1  wherein the first conductive contact comprises a first barrier layer on the sidewall and floor and a first conductive layer on the first barrier layer remote from the sidewall and floor and wherein the second conductive contact comprises a second barrier layer on the first conductive layer and a second conductive layer on the second barrier layer remote from the first conductive layer.  
     
     
         5 . An integrated circuit according to  claim 4  wherein the first and second barrier layers comprise titanium and/or titanium nitride and wherein the first and second conductive layers comprise tungsten.  
     
     
         6 . An integrated circuit according to  claim 1  wherein the first conductive contact also extends onto the first insulating layer outside the first hole.  
     
     
         7 . An integrated circuit according to  claim 1  wherein the second conductive contact also extends onto the second insulating layer outside the second hole.  
     
     
         8 . An integrated circuit according to  claim 1:   wherein the first insulating layer includes a third hole and a fourth hole passing therethrough; and    wherein the second insulating layer includes a fifth hole passing therethrough that exposes the fourth hole;    the integrated circuit further comprising: 
 a third conductive contact in the third hole; and  
 a fourth conductive contact in the fourth and fifth holes.  
   
     
     
         9 . An integrated circuit according to  claim 8  further comprising: 
 a third insulating layer on the second insulating layer remote from the first insulating layer that includes therein a sixth hole that exposes the second hole;  
 the second conductive contact further extending into the sixth hole.  
 
     
     
         10 . An integrated circuit according to  claim 8  further comprising: 
 a capacitor on the second insulating layer that is electrically connected to the fourth conductive contact.  
 
     
     
         11 . An integrated circuit according to  claim 9  wherein the second conductive contact also extends onto the third insulating layer outside the sixth hole.  
     
     
         12 . An integrated circuit according to  claim 8  wherein the first hole is at least twice as wide as the third hole.  
     
     
         13 . A method of fabricating an integrated circuit comprising: 
 forming a first insulating layer on a substrate;    forming a first hole passing through the first insulating layer and including a floor adjacent the substrate and a sidewall;    conformally forming a first conductive contact on the sidewall and floor to define a groove in the first hole;    forming a second insulating layer on the first insulating layer remote from the substrate;    forming a second hole passing through the second insulating layer and exposing the groove; and    forming a second conductive contact in the second hole and in the groove.    
     
     
         14 . A method according to  claim 13  wherein the step of forming a first insulating layer on a substrate comprises forming a first insulating layer directly on the substrate such that the floor is directly on the substrate.  
     
     
         15 . A method according to  claim 13  wherein the step of forming a second conductive contact comprises forming a second conductive contact to fill the second hole and the groove.  
     
     
         16 . A method according to  claim 13:   wherein the step of conformally forming a first conductive contact comprises forming a first barrier layer on the sidewall and floor and forming a first conductive layer on the first barrier layer remote from the sidewall and floor; and    wherein the step of forming a second conductive contact comprises forming a second barrier layer on the first conductive layer and forming a second conductive layer on the second barrier layer remote from the first conductive layer.    
     
     
         17 . A method according to  claim 16  wherein the first and second barrier layers comprise chemical vapor deposited titanium and/or titanium nitride and wherein the first and second conductive layers comprise chemical vapor deposited tungsten.  
     
     
         18 . A method according to  claim 13  wherein the step of conformally forming a first conductive contact comprises conformally forming a first conductive contact on the sidewall and floor and extending onto the first insulating layer outside the first hole.  
     
     
         19 . A method according to  claim 13  wherein the step of forming a second conductive contact comprises forming a second conductive contact in the second hole, in the groove and extending onto the second insulating layer outside the second hole.  
     
     
         20 . A method according to  claim 13:   wherein the step of forming a first hole passing through the first insulating layer and including a floor adjacent the substrate and a sidewall further comprises forming a third hole passing through the first insulating layer;    wherein the step of conformally forming a first conductive contact comprises conformally forming a first conductive contact on the sidewall and floor to define a groove in the first hole and simultaneously forming a third conductive contact in the third hole;    wherein the step of forming a second insulating layer is followed by forming a third insulating layer on the second insulating layer remote from the first insulating layer that includes therein a sixth hole that exposes the second hole; and    wherein the step of forming a second conductive contact comprises forming a second conductive contact in the second hole, in the groove and in the sixth hole.    
     
     
         21 . A method according to  claim 20  further comprising: 
 forming a fifth hole in the second insulating layer;  
 forming a fourth hole in the first insulating layer beneath the fifth hole; and  
 forming a fourth conductive contact in the fourth and fifth holes.  
 
     
     
         22 . A method according to  claim 21  further comprising: 
 forming a capacitor on the second insulating layer that is electrically connected to the fourth conductive contact.  
 
     
     
         23 . A method according to  claim 20  wherein the step of forming a second conductive contact further comprises forming a second conductive contact in the second hole, in the groove, in the sixth hole and extending onto the third insulating layer outside the sixth hole.  
     
     
         24 . A method according to  claim 20  wherein the first hole is at least twice as wide as a thickness of the conformal first conductive contact.  
     
     
         25 . A method according to  claim 13  wherein: 
 the step of conformally forming a first conductive contact on the sidewall and floor to define a groove in the first hole further comprises forming a third contact hole passing through the first insulating layer; and  
 wherein the step of conformally forming a first conductive contact comprises conformally forming a first conductive contact on the sidewall and floor to define a groove in the first hole and simultaneously forming a third conductive contact in the third hole.  
 
     
     
         26 . A method according to  claim 25  wherein the step of conformally forming a first conductive contact on the sidewall and floor to define a groove in the first hole and simultaneously forming a third conductive contact in the third hole comprises: 
 conformally forming a barrier layer conductive layer on the sidewall and floor and in the third contact hole;  
 forming a conductive layer on the barrier layer in the first hole to define the groove and on the barrier layer in the third hole to fill the third hole; and  
 patterning the barrier layer conductive layer and the conductive layer to form the first conductive contact and the third conductive contact.  
 
     
     
         27 . An integrated circuit according to  claim 4  wherein the first insulating layer includes a third contact hole and a fourth contact hole passing therethrough; and 
 wherein the second insulating layer includes a fifth hole passing therethrough that exposes the fourth hole;  
 the integrated circuit further comprising: 
 a third conductive contact in the third contact hole; and  
 a fourth conductive contact in the fourth and fifth holes.  
 
 
     
     
         28 . An integrated circuit according to  claim 7  wherein the third conductive contact comprises a third barrier layer that extends conformally inside the third contact hole and a third conductive layer on the third barrier layer.  
     
     
         29 . An integrated circuit according to  claim 27  wherein the third conductive contact also extends onto the first insulating layer outside the third contact hole.  
     
     
         30 . An integrated circuit according to  claim 27  wherein the first hole is at least twice as wide as the first conductive contact.