Atomic Layer Deposition of the Solid Electrolyte LiPON

Abstract

High Resolution Image Download MS PowerPoint Slide We demonstrate an atomic layer deposition (ALD) process for the solid electrolyte lithium phosphorousoxynitride (LiPON) using lithium tert -butoxide (LiO t Bu), H 2 O, trimethylphosphate (TMP), and plasma N 2 ( P N 2 ) as precursors. We use in-situ spectroscopic ellipsometry to determine growth rates for process optimization to design a rational, quaternary precursor ALD process where only certain substrate–precursor chemical reactions are favorable. We demonstrate via in-situ XPS tunable nitrogen incorporation into the films by variation of the P N 2 dose and find that ALD films over approximately 4.5% nitrogen are amorphous, whereas LiPON ALD films with less than 4.5% nitrogen are polycrystalline. Finally, we characterize the ionic conductivity of the ALD films as a function of nitrogen content and demonstrate their functionality on a model battery electrode—a Si anode on a Cu current collector.