Metal-insulator-metal capacitors based on lanthanum oxide high-κ dielectric nanolayers fabricated using dense plasma focus device

Abstract

Metal-insulator-metal (MIM) capacitors with lanthanum oxide (La2O3) high-κ dielectric, for potential applications in mixed-signal integrated circuit (IC), have been fabricated using a dense plasma focus device. The electrical characteristics and morphological properties of the fabricated nanodevices are studied. The MIM capacitors were further annealed to enhance the electrical properties in terms of the low leakage current density, the high capacitance density, and the improved capacitance voltage linearity. The minimum leakage current densities of ∼1.6 × 10−9 A/cm2 and ∼2.0 × 10−10 A/cm2 at −1 V are obtained along with the maximum capacitance densities of ∼17.96 fF/μm2 at 100 kHz and ∼19.10 fF/μm2 at 1 MHz, 0 V for as-fabricated and annealed MIM capacitors having 15 nm thick dielectric layers as measured using ellipsometry. The nanofilms with the minimum root mean square roughness of ∼10 nm are examined using atomic force microscopy. The results are superior compared to some other MIM capacitors and can be optimized to achieve the best electrical parameters for potential applications in radio frequency (RF)/mixed signal ICs. The high frequency C-V measurements indicate an increase in the capacitance density upon increasing the frequency which supports the possibility of potential high-frequency/RF applications of the MIM capacitors.