Gate Leakage Characteristics for 28 nm HfZrOx pMOSFETs After DPN Process Treatment With Different Nitrogen Concentration

Feasibly adjusting the gate leakage and the device performance in balance is an obvious challenge. Additionally, stacking the high-k dielectric as a gate dielectric in nanonode process is an appreciate way to promote the drive current in pMOSFETs. Unfortunately, the amount of oxygen vacancy or the interfacial layer thickness on the surface channel will possibly reduce the drive current owing to the increasing magnitude of threshold voltage and increase in the gate leakage degrading the standby capability in circuit operation. To retard this disadvantage or intensify the device quality, applying a lower pressure decoupled-plasma nitridation process to obliquely reform the amount of oxygen vacancy is a feasible alternative. On the basis of tested data, the nitridation treatment in a higher N₂ concentration is better than that in a lower one, such as the improvement of gate leakage, drive current, subthreshold swing, and channel mobility in pMOSFETs, especially for shorter channel-length devices.