Plasma Enhanced Atomic Layer Deposition of TiO2 using TDMAT and O2 plasma

Abstract

As devices are scaled down, ALD, which can be controlled to an accurate thickness was investigated for TiO2 as a spacer. We used remote plasma at lower temperatures and to reduce damage caused by ions. OES showed that the intensity of oxygen radicals was increased by applying higher power. From XPS data, the area of oxygen vacancy was reduced from 10.8% to 8.3% with increasing power, in contrast to the increase of area of metal oxide from 89.2% to 91.7%. XRR results showed density of TiO2 film at 100W of 4.09g/cm3 while density increased to 4.2g/cm3 at 500W due to oxygen radicals from the high plasma power. Also, the WER of TiO2 film was 1.72Å/min for 100W, and 0.8Å/min for 500W, and it was confirmed that denser film had good etch resistance. TEM showed that step coverage of TiO2 films was improved from 90.9% to 99.9% with increasing power.