ATOMIC LAYER DEPOSITION OF Hf3N4/HfO2 FILMS AS GATE DIELECTRICS

摘要

The use of atomic layer deposition (ALD) to form a dielectric layer of hafnium nitride (Hf₃N₄) and hafnium oxide (HfO₂) and a method of fabricating such a combination gate and dielectric layer produces a reliable structure for use in a variety of electronic devices. Forming the dielectric structure includes depositing hafnium oxide using precursor chemicals, followed by depositing hafnium nitride using precursor chemicals, and repeating to form the laminate structure. Alternatively, the hafnium nitride may be deposited first followed by the hafnium nitride. Such a dielectric layer may be used as the gate insulator of a MOSFET, a capacitor dielectric in a DRAM, or a tunnel gate insulator in flash memories, because the high dielectric constant (high-k) of the film provides the functionality of a thinner silicon dioxide film, and because of the reduced leakage current when compared to an electrically equivalent thickness of silicon dioxide.