No abstract

Atomic Layer Deposition (ALD) of TiO2 has potential applications in the microelectronics industry for purposes such as formation of the copper barrier layer. In this paper, TiO2 deposition on silicon and copper substrates is studied, with a focus on the initial growth and nucleation period on different substrates. Silicon with native oxide about 1.5 nm-thick, silicon with reduced oxide <1 nm-thick, and silicon/copper patterned substrates with native oxide are tested for TiO2 deposition. The temperature-independent window on silicon is studied, and findings are used encourage selective deposition on the silicon portions of a copper-patterned silicon substrate. Selective ALD is found to be possible on silicon portions by taking advantage of the 15-20 cycle TiO2 nucleation period on copper, allowing a film approximately 2.5 nm-thick to grow on silicon while less than two monolayers grow on copper. Findings can be used in future work to further promote selective deposition of TiO2.