Experimental study of interface traps in MOS capacitor with Al-doped HfO_2

摘要

Interface trap density (D-it) in a metal oxide semiconductor (MOS) capacitor with an aluminum-doped hafnium oxide (Al:HfO2) layer is investigated using the conductance method. Three device-under-tests (DUTs) were fabricated to investigate the impact of Al concentration in HfO(2)on D-it. Note that the atomic layer deposition cycle ratio of HfO2:Al(2)O(3)for DUT A, B, and C was varied from 3:1, 5:1, and 10:1, respectively. It was observed that the extracted D(it)of DUT C is 3.84 x 10(13)cm(-2)eV(-1)(which is the lowest value in the three DUTs). In addition, the measured leakage current of DUT C is the lowest. The optimum Al concentration in Al:HfO(2)would pave a new road for future CMOS technology.