In this study, we investigated the electrical characteristics of HfO2/La2O3/HfO2 capacitor (HLH capacitor) films. Lanthanum oxide (La2O3) and hafnium oxide (HfO2) films were deposited by an electron cyclotron resonance plasma-enhanced atomic layer deposition method (ECR-ALD). Tris(isopropyl-cyclopentadienyl)lanthanum (La(iPrCp)3) and tetrakis(ethylmethylamino) hafnium (TEMAHf) were utilized as the lanthanum and hafnium precursors, respectively. The leakage current of the HLH capacitor with 2/10/2 nm layers was about 2.20 × 10−10 A/cm2 at 1MV/cm and the dielectric constant of the film was 20.2. Based on leakage current mechanism research, the dominant conduction mechanism of the HLH capacitor is Poole-Frenkel (P-F) and space-charge-limited current (SCLC) conduction.

Keywords: hafnium oxide, lanthanum oxide, capacitor, high-k oxide.