Quantified Uniformity and Selectivity of TiO₂ Films in 45‐nm Half Pitch Patterns Using Area‐Selective Deposition Supercycles

Abstract

Area-selective deposition (ASD) shows great promise for sub-10 nm manufacturing in nanoelectronics, but significant challenges remain in scaling to ultrasmall dimensions and understanding feature-dependent nonuniformity and selectivity loss. This work addresses these problems by simultaneously quantifying uniformity and selectivity for passivation/deposition/etch supercycles in 45 nm half-pitch TiN/SiO 2 line/space patterns. This work employs three selective processes that are uniquely suited for supercycle processing: dimethylamino-trimethylsilane (DMA-TMS) inhibition, TiO 2 atomic layer deposition (ALD), and HBr/BCl 3 plasma etch. The DMA-TMS inhibition selectively passivates the SiO 2 nongrowth surface without affecting deposition on the TiN and TiO 2 growth surfaces. The plasma etch removes TiO 2 defect particles at a faster rate than the conformal TiO 2 film or SiO 2 lines. Using three supercycles of this process, this work demonstrates 8 nm of TiO 2 with 88% uniformity and ≈100% selectivity according to transmission electron microscopy (TEM), a 2×improvement in film thickness from previous reports in similar nanoscale patterns. Integrated consideration of uniformity and selectivity at specific feature scales will facilitate the effective design of selective deposition processes for nanoscale electronic devices.