Process for fabricating an ONO floating-gate electrode in a two-bit EEPROM device using rapid-thermal-chemical-vapor-deposition

摘要

A process for fabricating an ONO floating-gate electrode in a two-bit EEPROM device includes the formation of a first and second oxide layers using a high-temperature-oxide (HTO) deposition process in which the HTO process is carried out at a temperature of about 700 to about 800° C. The process further includes the sequential formation of a first silicon oxide layer, a silicon nitride layer, and a second silicon oxide layer using an RTCVD process in which the silicon nitride layer is not exposed to ambient atmosphere prior to the formation of the top oxide layer. The formation of the first and second oxide layers using an RTCVD process provides an improved two-bit EEPROM memory device by reducing charge leakage in the ONO floating-gate electrode.