4:30 PM - 4:45 PM
▲ [12p-N102-12] Low Temperature and High-Quality Neutral Beam Enhanced Atomic Layer Deposition of Hafnium Dioxide
Keywords:ALD, Hafnium dioxide thin film, Neutral beam
As the continuous scaling down of the SiO2 film as the gate oxide layer in CMOS technology in recent years was reaching its limit in terms of the size and the gate leakage current. The hafnium dioxide (HfO2) with high enough k-value, thermal stability, kinetic stability, reasonable energy gap, and good interface quality with Si make it one of the most promising candidates to replace SiO2. Neutral beam enhanced atomic layer deposition (NBEALD) method is a novel deposition technique, using the neutral beam to replace the plasma in the irradiation step of plasma enhanced (PE)ALD method. The inherent problems in the plasma process such as UV photon irradiation damage and charge-up damage could be overcome in the NBEALD process. Therefore, in this study, the high-k HfO2/SiO2/Si stacked film was continuously formed by using NBEALD system at room temperature 30℃.
About 1nm SiO2 interface layer was fabricated on the cleaned Si substrate by neutral beam oxidation (NBO) method, for SiO2/Si with better interface properties compared with the direct-contact HfO2/Si. To form the HfO2 film, TEMAH was used as a Hf precursor, O2 neutral beam was used as oxidants. Ar gas was, used as a carrier gas and purge gas. The NBEALD cycle consists 5 steps: TEMAH feed, TEMAH purge, O2 gas injection, O2 NB irradiation, O2 NB purge.
HfO2 thin film deposited by NBEALD, both carbon (2.7%) and nitrogen (3.9%) contamination ratio were low, even at low temperature 30℃. The O/Hf ratio was 2.03, which almost the same as thermal oxidation HfO2. Therefore, we succeeded to growth the low contamination HfO2/SiO2/Si stacked film at 30ºC by using NBEALD.
About 1nm SiO2 interface layer was fabricated on the cleaned Si substrate by neutral beam oxidation (NBO) method, for SiO2/Si with better interface properties compared with the direct-contact HfO2/Si. To form the HfO2 film, TEMAH was used as a Hf precursor, O2 neutral beam was used as oxidants. Ar gas was, used as a carrier gas and purge gas. The NBEALD cycle consists 5 steps: TEMAH feed, TEMAH purge, O2 gas injection, O2 NB irradiation, O2 NB purge.
HfO2 thin film deposited by NBEALD, both carbon (2.7%) and nitrogen (3.9%) contamination ratio were low, even at low temperature 30℃. The O/Hf ratio was 2.03, which almost the same as thermal oxidation HfO2. Therefore, we succeeded to growth the low contamination HfO2/SiO2/Si stacked film at 30ºC by using NBEALD.