Effect of the Hydrophilic-Lipophilic Balance (HLB) of Surfactants Included in the Post-CMP Cleaning Chemicals on Porous SiOC Direct CMP

To reduce the effective k-value for the 45-nm node, direct CMP of a porous SiOC film without a protective cap layer is required. The hydrophilic-lipophilic balance (HLB) of a surfactant included in the post-CMP cleaning chemical was found to be a parameter that determines SiOC film damage and cleaning ability after direct CMP. To suppress the k-value increase and watermark generation, we need to reduce the chemical and mechanical stress of the barrier metal CMP slurry and brush scrub cleaning. Moreover, IPA (or glycolether) cleaning and H₂/He remote plasma treatment are an effective restoring treatment after direct CMP.