Optimizing pulse protocols in plasma-enhanced atomic layer deposition

We use a transient, Boltzmann equation based transport and reaction model to study atomic layer deposition (ALD) at the feature scale, and focus on improving pulse protocols. We use this model to simulate plasma-enhanced ALD and to explain growth rate dependence on pulse times for two different processes for TBTDET sourced TaN recently reported in Park et al., J. Electrochem. Soc., 149(1), C28 (2002); ALD using ammonia as the co-reactant and plasma-enhanced ALD using a hydrogen plasma. We use the calibrated chemistry models to predict surface coverage and monolayers deposited over several ALD cycles. We conclude that the monolayers per cycle can be increased relative to the experimental data by shortening the post-adsorption purge time; this decreases reactant desorption. The overall growth rate can by increased by decreasing co-reactant and post-reaction purge pulse times; they are longer than necessary.