Gendt, “An assessment of the location of as-grown electron traps

Abstract—Replacing SiON by high-κ layers is a pressing issue for CMOS technologies. The presence of as-grown electron traps in HfO2 is a major obstacle, since they can induce threshold-voltage instability, reduce electron mobility, and result in early breakdown. Their location has not been clarified and is addressed in this letter. By selecting test conditions carefully and using sam-ples with a progressive reduction of HfO2 thickness, the authors are able to rule out that traps are piled up near the HfO2/HfSiO interface. A uniform distribution throughout HfO2 does not agree with the test data, either. Results support that trapping is negli-gible near to one or both ends of the HfO2 layer when compared with trapping in the central region. Index Terms—Defects, gate dielectrics, high-κ, instability, oxides, reliability, traps. I