Reliability Improvement of Rapid Thermal Oxide Using Gas Switching

摘要

The instantaneous switch-off of the gas precursors during the ramp-down cycle in a spike ramp process is demonstrated to be an effective method to enhance the reliability of rapid thermal oxide. Due to the slow ramp-down rate (60℃-90℃/s) of a rapid thermal process, the oxidation during the slow ramp-down cycle may produce the inferior oxide, especially for ultrathin oxide. To avoid the oxidation in the slow ramp-down cycle, the oxidation precursor (oxygen) is switched off during the ramp-down cycle. The reliability of resulting oxide without oxidation during the ramp-down cycle is enhanced as compared with the conventional oxide, which is still oxidized during the ramp-down cycle.