초록
Thin (25-103$\AA$) SiO$_2$ films are grown using the rapid thermal oxidation processing at temperatures of 105$0^{\circ}C$-115$0^{\circ}C$ for 5-30 sec, in order to investigate the characteristics of ultra thin oxide. For measuring the thickness of oxide TEM, ellipsometry, and C-V method which is taken in the condition of small surface band bending are used and compared. When neglecting the small deviation affected by both interface state and moisture charge effect, those three methods described above give similar results. In order to examine the effect of rapid thermal annealing, part of samples are annealed in N$_2$ ambient. MOS capacitors are fabricated and the characteristics of I-V and C-V are measured. Measurements show that the activation energy of initial thickness of oxide grown during the ramp-up time is of 1.125eV and the activation energy of the oxidation rate is of 0.98eV. As oxidation temperature is increased, dielectric breakdown field E$_{BD}$ is decreased due to the increase of fixed charge density N$_f$ However, E$_{BD}$ is shown to be decreased as increasing the thickness of oxide. The increase of N$_f$ in the early stage of thermal annealing results in the decrease of E$_{BD}$.