Effect of nitrogen sputtering pressure on the electronic properties of LiPON solid-state electrolyte

This study focuses on optimizing the sputtering deposition parameters to grow a LiPON solid-state electrolyte. Specifically, this study examines the impact of nitrogen deposition pressure on the electronic properties of LiPON solid-state electrolytes. Through a combination of scanning electron microscope analysis, X-ray diffraction studies, and chemical spectroscopy techniques, the study found that high nitrogen deposition pressure (20 mTorr) results in the formation of a discharge space with high-species concentration that reduces the mean free path of the ejected Li₃PO₄ target atoms. This leads to the growth of low-thickness films ( \(t=107 nm\) $t=107nm$ ) that lack nitrogen content and have a high-energy bandgap ( \({E}_{g}=4.69 eV\) $E_g=4.69eV$ ). On the other hand, low nitrogen deposition pressure (5 mTorr) results in the formation of a discharge space with low-species concentration that allows for the growth of thicker sputtered films ( \(t=315 nm\) $t=315nm$ ) with the correct stoichiometry of the LiPON phase. This leads to a lower energy bandgap ( \({E}_{g}=4.51 eV\) $E_g=4.51eV$ ).