Effect of Oxidant on Downstream Microwave Plasma-Enhanced CVD of Hafnium Oxynitride Films

Hafnium oxynitride films were deposited using downstream microwave plasma‐enhanced (DMPE) CVD in O2, N2O, O2/He, and N2O/N2 with hafnium tetrakis‐diethylamide (Hf(NCH2CH3)4, TDEAH) as the precursor. The effects of plasma‐activated oxidant on structures and properties of deposited hafnium oxynitride films were studied. Films deposited using DMPECVD have amorphous morphologies, while films deposited using metal‐organic (MO) CVD are crystallized in the same deposition temperature range. Also, films from DMPECVD contain more interstitial oxygen atoms that degrade the electrical properties of films. Increasing the deposition temperature reduces the electrical degradation of deposited films. Oxygen radicals in plasma‐activated oxidant are regarded as the reason for amorphous structures and incorporated interstitial oxygen atoms. Hafnium oxynitride films are deposited by downstream microwave plasma‐enhanced CVD (DMPECVD). The effects of plasma‐activated oxidants on the morphology, composition, and electrical properties of deposited dielectric films are studied. Films deposited using DMPECVD have amorphous morphologies, and contain more interstitial oxygen atoms that degrade the electrical properties of films than films deposited using metal‐organic (MO)CVD.