ULTRA LOW K (ULK) SiCOH FILM AND METHOD

Abstract

The present invention provides a multiphase, ultra low k film which exhibits improved elastic modulus and hardness as well as various methods for forming the same. The multiphase, ultra low k dielectric film includes atoms of Si, C, O and H, has a dielectric constant of about 2.4 or less, nanosized pores or voids, an elastic modulus of about 5 or greater and a hardness of about 0.7 or greater. A preferred multiphase, ultra low k dielectric film includes atoms of Si, C, O and H, has a dielectric constant of about 2.2 or less, nanosized pores or voids, an elastic modulus of about 3 or greater and a hardness of about 0.3 or greater. The multiphase, ultra low k film is prepared by plasma enhanced chemical vapor deposition in which one of the following alternatives is utilized: at least one precursor gas comprising siloxane molecules containing at least three Si—O bonds; or at least one precursor gas comprising molecules containing reactive groups that are sensitive to e-beam radiation. Electronic structures including the multiphase, ultra low k film are also disclosed.

1 . An electronic structure comprising at least a multiphase, ultra low k film including atoms of Si, C, O and H, said film having a dielectric constant of about 2.4 or less, nanosized pores or voids, an elastic modulus of about 5 or greater and a hardness of about 0.7 or greater. 
   
   
       2 . An electronic structure comprising multiphase, ultra low k dielectric film including atoms of Si, C, O and H, said film having a dielectric constant of about 2.4 or less, nanosized pores or voids, an elastic modulus of about 5 or greater and a hardness of about 0.7 or greater and a dense region at the top surface of said film. 
   
   
       3 . The electronic structure of  claim 1  wherein said multiphase, ultra low k film is an interlevel or intralevel dielectric of a back-end-of-the-line (BEOL) wiring structure. 
   
   
       4 . The electronic structure of  claim 1  wherein said multiphase, ultra low k film is a cap or diffusion barrier of a BEOL wiring structure. 
   
   
       5 . The electronic structure of  claim 1  wherein said multiphase, ultra low k film is a hard mask or a polish stop layer for a BEOL wiring structure