Enabling single-wafer low temperature radical oxidation

This paper reports the study of low temperature radical oxidation by using highly concentrated ozone gas in a single-wafer rapid thermal processor. As device structures continue to shrink in geometry, integration of new materials and the complexity of process flows demand growth of high quality oxides with reduced thermal budget. This requirement poses a major challenge for thermal oxidation since lowering the process temperature causes degradation of oxide film quality, in general. Based on the fact that RadOxtrade have already demonstrated unique advantages in a variety of applications for current devices, it is expected that enabling radical oxidation at lower temperature would be beneficial for advanced devices. Highly concentrated ozone gas was employed as the source of radicals. The ozonator used for this study is capable to produce a gas mixture up to 90 vol% ozone (in oxygen) safely by adsorption/desorption technique. Several design of experiments (DOE) were carried out for thickness and thickness non-uniformity study, and film properties were compared with baseline processes using non-contact electrical measurements