SONOS memory cells having non-uniform tunnel oxide and methods for fabricating same

摘要

Methods for forming a memory cell are disclosed. A method includes forming a source-drain structure in a semiconductor substrate where the source-drain structure includes a rounded top surface and sidewall surfaces. An oxide layer is formed on the top and sidewall surfaces of the source-drain structure. The thickness of the portion of the oxide layer that is formed on the top surface of the source-drain structure is greater than the thickness of the portion of the oxide layer that is formed on the sidewall surfaces of the source-drain structure.