Integration compatible porous SiCOH dielectrics from 45 to 22 nm

Abstract

We have developed two classes of porous SiCOH (pSiCOH) dielectric for integration in back end of the line (BEOL) interconnects. Here, we compare these materials at the k values 2.4 and 2.2. Class 1 ("V1") pSiCOH has a skeleton of O-Si-O bonds, with nm scale pores and carbon bonded as Si-CH3. Class 2 ("V2") contains added Si-C-Si structures, which are chemically stable methylene groups (-CH2-) bonded between 2 Si atoms. This paper compares some properties of the dielectrics, and integration compatibility of the V1 and V2 materials is examined using damascene Cu integration results. These results indicate that V2 pSiCOH is more resistant than V1 pSiCOH to the processing damage of copper damascene integration. © 2009 Materials Research Society.