摘要
Gadolinium oxide(Gd2O3) film has potential as a candidate gate dielectric to replace Hf O2. In this work,we provide a simple method by trace Ta(~1%) doping to significantly improve the dielectric properties of Gd2O3 film. And effects of annealing temperatures of Ta-doped Gd2O3(GTO) films are investigated in detail. Results show that GTO film annealed at 500℃ exhibits excellent performance as a novel gate dielectric material for integrated circuit, showing a small surface roughness of 0.199 nm, a large band gap of 5.45 e V, a high dielectric constant(k) of 21.2 and a low leakage current density(Jg) of 2.10 × 10^-3A/cm^2.All properties of GTO films are superior to pure Gd2O3 films and these GTO films meet the requirements for next-generation gate dielectrics. In addition, impedance spectrum is first used to analyze the equivalent circuit of GTO based metal-oxide-semiconductor(MOS) capacitors, which represents a new insight to understand observed electrical behaviors.
Gadolinium oxide（Gd2O3） film has potential as a candidate gate dielectric to replace Hf O2. In this work,we provide a simple method by trace Ta（～1%） doping to significantly improve the dielectric properties of Gd2O3 film. And effects of annealing temperatures of Ta-doped Gd2O3（GTO） films are investigated in detail. Results show that GTO film annealed at 500℃ exhibits excellent performance as a novel gate dielectric material for integrated circuit, showing a small surface roughness of 0.199 nm, a large band gap of 5.45 e V, a high dielectric constant（k） of 21.2 and a low leakage current density（Jg） of 2.10 × 10-3A/cm2.All properties of GTO films are superior to pure Gd2O3 films and these GTO films meet the requirements for next-generation gate dielectrics. In addition, impedance spectrum is first used to analyze the equivalent circuit of GTO based metal-oxide-semiconductor（MOS） capacitors, which represents a new insight to understand observed electrical behaviors.
基金
supported financially by the Project of Ministry of Science and Technology of the People’s Republic of China (No. 2017YFB0405902)
the National Natural Science Foundation of China (Nos. 51431001, 51771002, 21771006, U1607126 and 21621061)
Beijing Municipal Commission of Science and Technology (No. Z17110000091702)
