Self-Aligned Nanopatterning and Controlled Lateral Growth by Dual-Material Orthogonal Area-Selective Deposition of Poly(3,4-ethylenedioxythiophene) and Tungsten

Despite recent advances in area-selective deposition (ASD) processes, most studies have focused on single-material ASD. Multi-material ASD processes could provide additional flexibility for fabricating semiconductor devices. In this work, we identify process requirements to sequentially combine two intrinsic ASD processes: (1) poly(3,4-ethylenedioxythiophene) (PEDOT) ASD on SiO 2 vs Si–H via oxidative chemical vapor deposition and (2) W ASD on Si–H vs SiO 2 via atomic layer deposition. Using ex situ X-ray photoelectron spectroscopy, we show that a preferred orthogonal ASD sequence involves PEDOT ASD on SiO 2 vs Si–H, followed by W ASD on Si–H vs PEDOT. We find that the properties of the individual PEDOT and W ASD materials, including resistivity, surface roughness, and growth rate, are affected by the ASD sequence. Furthermore, we successfully demonstrate that orthogonal ASD can be extended to nanoscale starting patterns. The cross-sectional scanning transmission electron microscopy (STEM) with energy-dispersive X-ray spectroscopy analysis shows that the resulting PEDOT thickness on SiO 2 depends on feature geometry and dimension. Finally, we demonstrate the feasibility that the PEDOT layer can control the lateral growth of W onto the non-growth surface.