| Abstract: | A multi-deposition multi-annealing technique(MDMA) is introduced into the process of high-k/metal gate MOSFET for the gate last process to effectively reduce the gate leakage and improve the device's performance. In this paper, we systematically investigate the electrical parameters and the time-dependent dielectric breakdown(TDDB) characteristics of positive channel metal oxide semiconductor(PMOS) under different MDMA process conditions, including the deposition/annealing(DA) cycles, the DA time, and the total annealing time. The results show that the increases of the number of DA cycles(from 1 to 2) and DA time(from 15 s to 30 s) can contribute to the results that the gate leakage current decreases by about one order of magnitude and that the time to fail(TTF) at 63.2% increases by about several times. However, too many DA cycles(such as 4 cycles) make the equivalent oxide thickness(EOT) increase by about 1 ?A and the TTF of PMOS worsen. Moreover, different DA times and numbers of DA cycles induce different breakdown mechanisms. |
