Two-step nitride deposition

摘要

A method is provided for fabricating a nitride layer of the semiconductor integrated circuit on a semiconductor substrate in a processing chamber. Source gases are applied to the processing chamber and a first nitride layer is deposited over the semiconductor substrate according to the source gases. The source gases are discontinued and the processing chamber is pumped out. Source gases are again applied to the processing chamber and a second nitride layer is deposited upon the first nitride layer according to the applied source gases. The first and second nitride layers form a combined nitride layer. Four alternate embodiments are set forth. In the first embodiment a predetermined amount of time is waited between the pumpout of the processing chamber and the deposition of the second nitride layer. The amount of time can be approximately ten minutes. In the second embodiment, the processing chamber is purged with nitrogen gas prior to depositing the second nitride layer. The purge can extend for between two minutes and sixty minutes. In the third embodiment the processing chamber is purged with nitrous oxide prior to depositing the second nitride layer. In the fourth embodiment the processing chamber is purged with nitrous oxide and an oxide layer is formed upon the first nitride layer prior to depositing the second nitride layer. In each of the embodiments the first nitride layer can be between 20% and 80% of the total combined thickness of the first and second nitride layers./!