# Remarkably High Dielectric Constant and Capacitance Density by Ni/ZrO2/TiN Using Nanosecond Laser and Surface Plasma Effect

## TL;DR

A new laser-based annealing method improves the dielectric properties of ZrO2 in capacitors, enabling higher performance for advanced electronics.

## Contribution

A novel surface plasma effect using a 532 nm nanosecond laser achieves record-high dielectric constant and capacitance density in Ni/ZrO2/TiN capacitors.

## Key findings

- A dielectric constant of 67.8 and capacitance density of 75 fF/μm2 were achieved using 15 ns pulsed laser annealing.
- The surface plasma effect on TiN enables effective annealing of ZrO2 at laser energy densities of 16.2 J/cm2.
- Enhanced crystallinity of cubic-phase ZrO2 is responsible for the improved dielectric performance.

## Abstract

Rapid thermal annealing (RTA) has been widely used in semiconductor device processing. However, the rise time of RTA, limited to the millisecond (ms) range, is unsuitable for advanced nanometer-scale electronic devices. Using sub-energy bandgap (EG) 532 nm ultra-fast 15 nanosecond (ns) pulsed laser annealing, a record-high dielectric constant (high-κ) of 67.8 and a capacitance density of 75 fF/μm2 at −0.2 V were achieved in Ni/ZrO2/TiN capacitors. According to heat source and diffusion equations, the surface temperature of TiN can reach as high as 870 °C at a laser energy density of 16.2 J/cm2, effectively annealing the ZrO2 material. These record-breaking results are enabled by a novel annealing method—the surface plasma effect generated on the TiN metal. This is because the 2.3 eV (532 nm) pulsed laser energy is significantly lower than the 5.0–5.8 eV energy bandgap (EG) of ZrO2, making it unabsorbable by the ZrO2 dielectric. X-ray diffraction analysis reveals that the large κ value and capacitance density are attributed to the enhanced crystallinity of the cubic-phase ZrO2, which is improved through laser annealing. This advancement is critical for monolithic three-dimensional device integration in the backend of advanced integrated circuits.