Using Inherent Substrate-Dependent Nucleation to Promote Metal and Metal Oxide Selective-Area Atomic Layer Deposition

摘要

We report studies of thin film metal and metal oxide nucleation during ALD to promote native substrate bias and improve selectivity. Tungsten ALD using WF_6/SiH_4 onto SiO_2 proceeds when surface Si-H begins to form, allowing WF_6 reduction to W and elimination of SiF_4. In-situ analysis indicates that initial nucleation reactions can be impeded on SiO_2 by introducing reactants that help passivate active surface sites. Moreover, eliminating water during TiO_2 ALD slows metal substrate oxidation to promote nucleation delay.