Electronic structures utilizing etch resistant boron and phosphorus materials and methods to form same

Abstract

A dense boron-based or phosphorus-based dielectric material is provided. Specifically, the present invention provides a dense boron-based dielectric material comprised of boron and at least one of carbon, nitrogen, and hydrogen or a dense phosphorus-based dielectric comprised of phosphorus and nitrogen. The present invention also provides electronic structures containing the dense boron-based or phosphorus-based dielectric as an etch stop, a dielectric Cu capping material, a CMP stop layer, and/or a reactive ion etching mask in a ULSI back-end-of-the-line (BEOL) interconnect structure. A method of forming the inventive boron-based or phosphorus-based dielectric as well as the electronic structure containing the same are also described in the present invention.

1 . An electronic structure having layers of insulating material as intralevel or interlevel dielectrics in a wiring structure comprising:
 a preprocessed semiconducting substrate;   an interlayer or intralayer dielectric (ILD) located atop substrate, said ILD including at least one conductive feature embedded therein; and   a dense dielectric comprising either (i) boron and at least one of carbon, nitrogen and hydrogen or (ii) phosphorus and nitrogen, wherein said dense dielectric and said ILD are in intimate contact and top surfaces of said ILD and said at least one conductive feature are essentially coplanar.   
     
     
         2 . The electronic structure of  claim 1  wherein said dense dielectric comprises boron and further at least one of Si, F, P and Ge. 
     
     
         3 . The electronic structure of  claim 2  wherein said dense dielectric comprises B x C y R z  or B x N y R z  wherein x, y and z are integers that represent a range of each component and R is a substitutent selected from the group consisting of halogens, hydrogen, alkyl, aryl, alkoxy, amino and substituted amino. 
     
     
         4 . The electronic structure of  claim 1  wherein said dense dielectric has a density from about 0.9 to about 2.0 grams/cm 3 . 
     
     
         5 . The electronic structure of  claim 1  wherein said dense dielectric is a dielectric diffusion barrier layer to cap a conductive material located in a conductive feature below said dense dielectric. 
     
     
         6 . The electronic structure of  claim 5  wherein said dense dielectric is a single layer. 
     
     
         7 . The electronic structure of  claim 5  wherein said dense dielectric is a top layer of a bilayer structure. 
     
     
         8 . The electronic structure of  claim 1  wherein said dense dielectric is a buried etch stop layer located at the bottom of a conductive line located within said ILD. 
     
     
         9 . The electronic structure of  claim 1  wherein said dense dielectric is a chemical mechanical polish stop layer, wherein an upper surface of said dense dielectric is essentially coplanar with an upper surface of said conductive material. 
     
     
         10 . The electric structure of  claim 1  wherein said dense dielectric comprises phosphorus and optionally at least one of hydrogen, nitrogen, silicon, germanium and fluorine. 
     
     
         11 . A method to deposit a layer of dense boron-based dielectric on a substrate comprising:
 positioning a substrate in a chemical vapor deposition reactor;   flowing a first precursor gas including either (i) boron in combination with at least one of C, N, and H or (ii) phosphorus and nitrogen, into said CVD reactor;   providing energy to at least said first precursor gas; and   depositing a dense dielectric film comprising either (i) boron in combination with at least one of C, N, and H or (ii) phosphorus and nitrogen on said substrate.   
     
     
         12 . The method of  claim 11  wherein said dense dielectric film comprises boron and further including at least one of Si, F, P and Ge. 
     
     
         13 . The method of  claim 11  wherein said chemical vapor deposition comprises a parallel plate-type plasma reactor or a remote plasma reactor or an inductively coupled plasma reactor. 
     
     
         14 . The method of  claim 11  wherein said first precursor gas is selected from the group consisting of carborane, decaborane, borazine, substituted borazines, alkylamino substituted borazines, borazines substituted with alkoxy, fluorine or other halogens, a derivative of carborane and a fullerene cage molecule containing BN groups. 
     
     
         15 . A boron-based dielectric material comprising boron and at least one of C, N, and H, wherein said boron is present in an amount from about 5 to about 90 atomic percent, and said dielectric has a density from about 0.9 to about 2.0 gm/cm 3 . 
     
     
         16 . The boron-based dielectric material of  claim 15  wherein C is present in an amount from about 5 to about 50 atomic percent. 
     
     
         17 . The boron-based dielectric material of  claim 15  wherein N is present in an amount from about 5 to about 50 atomic percent. 
     
     
         18 . The boron-based dielectric material of  claim 15  wherein H is present in an amount from about 20 to about 60 atomic percent. 
     
     
         19 . The boron-based dielectric material of  claim 15  further comprising at least one of Si, F, P and Ge. 
     
     
         20 . A phosphorus-nitrogen-based dielectric material comprising P and N and optionally at least one of hydrogen, silicon, germanium and fluorine, said dielectric has a density from about 0.9 to about 2.0 gm/cm 3  and a phosphorus content from about 3 to about 50 atomic percent and a nitrogen content from about 3 to about 50 atomic percent.