Year: 2019
Type: conference-paper
Abstract: We systematically investigated characteristics of Pt-gated capacitors with four kinds of gate insulators such as Hf 0.57 Si 0.43 O x , Hf 0.64 Si 0.36 O x , HfO 2 , and Al 2 O 3 . The Hf 0.64 Si 0.36 O x films fabricated by post-deposition annealing (PDA) at 800°C in O 2 (PDO), N 2 (PDN), and 3% H 2 (PDH) ambient exhibited quite different characteristics. After PDO, the Hf 0.64 Si 0.36 O x film was partially crystallized and had a thick interfacial layer at the n-GaN/Hf 0.64 Si 0.36 O x interface, while the Hf 0.64 Si 0.36 O x films after PDN and PDH maintained an amorphous structure. The PDH capacitor exhibited an order of magnitude larger interface state density than the PDN capacitor, indicating that the PDN process can produce superior Hf 0.64 Si 0.36 O x film. The Hf 0.57 Si 0.43 O x ,Hf 0.64 Si 0.36 O x , HfO 2 , and Al 2 O 3 films after PDA at 800°C in N 2 were 15.4, 15.9, 17.6, and 9, respectively. The HfO 2 and Al 2 O 3 films consist of polycrystalline structure while the Hf 0.57 Si 0.43 O x and Hf 0.64 Si 0.36 O x films maintain an amorphous structure. The different structure strongly affected to electrical properties. The Hf 0.57 Si 0.43 O x and Hf 0.64 Si 0.36 O x capacitors showed superior electrical properties such as a minimal flatband voltage ( V fb ) hysteresis ( ≤ +70 mV) and a small V fb shift ( ≤ -0.46 V), as well asa low interface state density (~ 3 × 10 11 cm -2 eV -1 at -0.45 eV fromconduction band), and a high breakdown electric field ( ≥ 8.6 MV/cm) compared to those of the HfO 2 and Al 2 O 3 capacitors.
Source: ECS Transactions
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2979257580