High-Quality SiO₂Film Formation below 400 °C by Plasma Enhanced Chemical Vapor Deposition Using Tetraethoxysilane Source Gas

Abstract

The plasma enhanced chemical vapor deposition (PECVD) of extremely high-quality SiO2 at low temperature below 400 °C has been developed using tetraethoxysilane (TEOS). Plasma of TEOS and Ar, O2 gases was generated by a microwave (2.45 GHz) radial-line-slot-antenna (RLSA) system. The RLSA Plasma is a sort of surface-wave-plasma (SWP) and it realizes lower electron temperature (Te) with higher electron density (Ne) at the wafer position compared with conventional PECVD reactors. The physical properties were examined by 5% HF wet etching rates and thermal desorption spectroscopy. It was confirmed that the RLSA TEOS film were much better than conventional PECVD films and a high temperature oxide (HTO) with 900 °C N2 anneal treatment. Electrical properties of dielectric leakage, breakdown and negative bias charge-to-breakdown (Qbd) test also performed. The RLSA TEOS films showed far better properties among the conventional films and in much the same quality as a wet-thermal oxide grown at 950 °C. It was considered that all these properties were owing to the RLSA plasma's uniqueness of lower plasma damage and oxidization efficiency for precursors.

High Integrity SiO2Gate Insulator Formed by Microwave-Excited Plasma Enhanced Chemical Vapor Deposition for AlGaN/GaN Hybrid Metal–Oxide–Semiconductor Heterojunction Field-Effect Transistor on Si Substrate

“…Details of MW-PECVD equipment have been described in ref. 31 and the CCP-CVD is a conventional system using the standard frequency of 13.56 MHz. The thickness of SiO 2 films is around 50 nm.…”

“…30) To date, excellent properties of SiO 2 film formed on Si by MW-PECVD has been reported. 31) In this paper, high integrity SiO 2 gate insulator formed on GaN by MW-PECVD is demonstrated. Furthermore, the SiO 2 gate insulator have been applied to AlGaN/GaN hybrid MOS-HFETs.…”

High Quality SiO2/Al2O3 Gate Stack for GaN Metal–Oxide–Semiconductor Field-Effect Transistor

“…The n-type GaN layer was grown by metal organic vapor-phase epitaxy (MOVPE) system. Al 2 O 3 films were formed by ALD using trimethylaluminum (TMA)/O 3 /O 2 gases as Al and O sources at 300 C. SiO 2 films were deposited by MW-PECVD at 400 C. 38) Annealing process was performed by a furnace at several temperatures for 30 min in N 2 ambient. Ohmic electrode on the n-type GaN layer and the gate electrode on gate insulator were fabricated by sputter deposition equipment.…”

High Performance Normally-off GaN MOSFETs on Si Substrates

“…SiO 2 films were deposited below 400 o C by MW-PECVD and CCP-CVD at 800 o C by the LP-CVD on the n-type GaN layer. Details of MW-PECVD equipment have been described in [15] and the CCP-CVD and the LP-CVD are conventional systems. The thickness of SiO 2 is around 50 nm.…”