A rigorous method of obtaining the Cu diffusivities in various SiO 2-based dielectric materials is proposed. The diffusion profile of Cu ions in a dielectric material is first simulated and the resulting flatband voltage shift (ΔVFB) is compared with the experimental results obtained by C-V measurements after bias-temperature stressing (BTS). The evolution of the Cu concentration in dielectric materials is evaluated using a one-dimensional finite differential method with two unknown parameters, the diffusivity, and the maximum solid solubility of Cu ions in the dielectric material. C-V measurements are conducted at 1 MHz to measure the ΔV FB value of Cu/SiO2/Si capacitors before and after BTS at an electric field of +1.0 MV/cm and in the temperature range between 200 and 275°C. With this process, the Cu diffusivities in thermally grown SiO 2, oxynitride and SiO2 deposited by plasma-enhanced chemical vapor deposition, and methyl-doped SiO2 are found to be 2.22 × 10-3 exp(-1.54 eV/kT), 3.09 × 10-5 exp(-1.34 eV/kT), 2.59 × 10-5 exp(-1.18 eV/kT), and 6.07 × 10-9 exp(-0.71 eV/kT), respectively.
Bibliographical noteFunding Information:
This work was supported by Samsung Electronics Co., Ltd. The authors are grateful to the Brain Korea 21 scholarship funded by the Ministry of Education, Korea. This work was supported by the Nano Systems Institute-National Core Research Center (NSI-NCRC) program of KOSEF, Korea.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)