Top-gate zinc tin oxide thin-film transistors with high bias and environmental stress stability

• Published in: Applied physics letters Vol. 104; no. 25
• Main Authors: Fakhri, M., Theisen, M., Behrendt, A., Görrn, P., Riedl, T.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 23-06-2014
• Subjects: ALUMINIUM OXIDES; Aluminum oxide; Applied physics; Atomic layer epitaxy; BENCHMARKS; Bias; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DAMAGE; DEPOSITION; DIELECTRIC MATERIALS; Dielectrics; ENCAPSULATION; Energetic particles; Gas permeation; High temperature; Laminates; LAYERS; Metal oxides; Semiconductor devices; STABILITY; STRESSES; Thin film transistors; THIN FILMS; TIN ADDITIONS; Tin oxides; TRANSISTORS; ZINC OXIDES; Zirconium dioxide; ZIRCONIUM OXIDES
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4885362

Top gated metal-oxide thin-film transistors (TFTs) provide two benefits compared to their conventional bottom-gate counterparts: (i) The gate dielectric may concomitantly serve as encapsulation layer for the TFT channel. (ii) Damage of the dielectric due to high-energetic particles during channel deposition can be avoided. In our work, the top-gate dielectric is prepared by ozone based atomic layer deposition at low temperatures. For ultra-low gas permeation rates, we introduce nano-laminates of Al2O3/ZrO2 as dielectrics. The resulting TFTs show a superior environmental stability even at elevated temperatures. Their outstanding stability vs. bias stress is benchmarked against bottom-gate devices with encapsulation.