Room-temperature and high-quality HfO2/SiO2 gate stacked film grown by neutral beam enhanced atomic layer deposition

Abstract

This study reports the fabrication of the high-quality hafnium dioxide (HfO2) film at room temperature (20–30 °C) using the neutral beam enhanced atomic layer deposition (NBEALD) we developed. The HfO2 film was fabricated using tetrakis(ethylmethylamino)hafnium (TEMAH) as the Hf precursor and O2 NB as the oxidant. Argon gas was used for the carrier and purge gases. The HfO2 film-deposition process consists of 5-s TEMAH feed, 5-s Ar purge, 5-s O2 gas injection, 20-s O2 neutral beam irradiation, and 5-s Ar purge. The HfO2 film exhibited a saturated growth per cycle of 0.18 nm/cycle and a high-quality film with low C contamination (2.7%), N contamination (3.9%), and a good O/Hf ratio (2.0) was achieved. The film also had an ideal refractive index of 1.9. Additionally, continuously grown high-quality HfO2 and silicon dioxide (SiO2) gate oxide films (stacked HfO2/SiO2 gate oxide film) were successfully fabricated at room temperature. This film has the potential to decrease the thermal budget, thus enabling high flexibility when designing semiconductor structures. These findings demonstrate the effectiveness of our NBEALD in forming high-k gate stack structures.

Emerging Plasma Nanotechnology

“…28) In this paper, we discuss the application of sub-10-nm structure fabrication technology to several devices, [12][13][14][15][16][17][18][19][20][21] a low-k film deposition technique utilizing control of polymerization reactions at the atomic level, 22) and an oxidation reaction for metal oxide (HfO 2 ) deposition. 23)…”

“…Dielectric Film 23) The transistor technical node has recently been scaled down to 5 nm, and the production of 3-nm transistors was started in 2021. Today's integrated circuits (ICs) are typically composed of metal-oxide-semiconductor field-effect transistors (MOSFETs), and the physical thickness of the conventional gate dielectric material (silicon dioxide (SiO 2 )) has become thinner.…”

“…In this study, we utilized NBEALD to fabricate high-quality HfO2 film at 30 ºC. 23) We formed an HfO2/SiO2/Si stacked structure and investigated the resultant HfO 2 /SiO 2 stacked gate oxide films. NBEALD was able to continuously form the interface SiO2 film and high-k HfO 2 film.…”

“…The precursor gas line was maintained at 100 ºC, and the chamber wall was maintained at 120 ºC to prevent precursor condensation and clogging during transport. 23) The stage temperature was controlled at 30 ºC. An Ar purge step with 30 sccm of Ar flow was applied after the precursor feed and NB irradiation steps.…”

“…in order to realize the optimum chemistry according to the material. [19][20][21] In this paper, we review the neutral beam generation technique 7,8) developed by S. Samukawa and investigate research on its application to atomic layer etching (ALE) [19][20][21] and deposition (ALD) 22,23) .…”