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/SiO2 line/space patterns. This work employs three selective processes that are uniquely suited for supercycle processing: dimethylamino-trimethylsilane (DMA-TMS) inhibition, TiO2 atomic layer deposition (ALD), and HBr/BCl3 plasma etch. The DMA-TMS inhibition selectively passivates the SiO2 nongrowth surface without affecting deposition on the TiN and TiO2 growth surfaces. The plasma etch removes TiO2 defect particles at a faster rate than the conformal TiO2 film or SiO2 lines. Using three supercycles of this process, this work demonstrates 8 nm of TiO2 with 88% uniformity and approximate to 100% selectivity according to transmission electron microscopy (TEM), a 2ximprovement 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.