Interactions of Metal-Organic PEALD TaN with Ultra-Low k Dielectric Materials

Abstract

Both dense and porous patterned ultra-low k (ULK) substrates have been characterized in terms of their interaction with TaN grown by plasma enhanced atomic layer deposition (PEALD). The conformal nature of the deposited TaN films by PEALD was demonstrated on a patterned dense oxide substrate. For the case of ULK dielectric materials with a dielectric constant of 2.55 (ULK2.55), penetration of TaN into the ULK matrix was observed for porous ULK2.55 while dense ULK2.55 did not exhibit any significant penetration of TaN. Both hydrogen plasma-based PEALD TaN and ammonia plasma-based PEALD TaN processes were shown to display a similar interaction with ULK2.2. A dielectric pore-sealing layer applied on patterned ULK2.2, prior to the deposition of TaN, enabled a significant reduction in PEALD TaN penetration as observed at ULK sidewalls.