Rapid thermal oxidation of silicon in ozone

Abstract

Rapid thermal oxidation (RTO) of Si in ozone gas is studied at temperatures between 200 and 550 °C, and the properties of the resulting ultrathin oxides are characterized using in situ mirror-enhanced reflection Fourier transform infrared (IR) spectroscopy. Thus, the frequency and intensity of the longitudinal optical vibrational mode of the Si–O–Si asymmetric stretching from ultrathin oxide films (<30 Å) are probed in different processing environments and related to the oxidation kinetics and interfacial layer properties. The oxidation rate in ozone is found to be comparable to the one in pure oxygen at approximately 200 °C higher temperature. Analyses of the oxidation in ozone show a fast oxidation regime followed by a slow one with activation energies of 0.13±0.01 and 0.19±0.04 eV, respectively. Two regions are also observed for the oxidation in pure O2 with activation energies of 0.20±0.03 eV for the fast oxidation regime and 0.36±0.04 eV for the slow one. X-ray photoelectron spectroscopy results and IR spectral feature frequency shifts suggest that the RTO of silicon in ozone ambient results in a thinner, less-stressed interfacial layer than the one obtained in pure O2. Preliminary electrical characterization using surface charge analyses indicates that the oxides formed in ozone are of superior quality.

Synthesis of silicon dioxide film using high-concentration ozone and evaluation of the film quality

“…However, the value of 0.15 eV for ozone oxidation was inferior to the activation energies in the range 0.06-0.1 eV measured in plasma oxidation and electron-cyclotron-resonance oxidation. 16 This result suggests that the high energy oxygen atoms in a state excited by an electronic cyclotron or plasma, which cannot be obtained by the thermal dissociation of ozone, contribute effectively to the oxidation reaction.…”

Deposition of O atomic layers on Si(100) substrates for epitaxial Si-O superlattices: investigation of the surface chemistry

“…While many studies have focused on the O 3 reaction with Si substrates for oxidation [48][49][50]. Yet, there are only a limited number of papers that have investigated the initial stages of the O 3 reaction with H-terminated Si, where the reaction can be controlled near/at the atomic layer content [21].…”

New functionalities in abundant element oxides: ubiquitous element strategy

“…• C [64] are included in figure 20. The results indicate that the irradiation-assisted oxidation can yield the same oxide thickness as the thermal oxidation, but at a substrate temperature lower by a few hundred degrees.…”

“…In this subsection, surface oxidation of Si is examined. Low-temperature formation of ultrathin oxide layers on semiconductors [63][64][65] is particularly important in the microelectronics industry for high-density device fabrication on glass or plastic substrates.…”