高k栅介质Al微掺杂HfO_2电学特性研究

Study on the Electrical Characteristic of Al Doped High kGate Dielectric

随着纳米器件的进一步微缩,Hf基高k材料已无法满足其发展需求,需要引入新的高k材料.为了减小纳米器件的等效氧化层厚度(EOT),向HfO_2中掺入Al元素,并分别在N_2、O_2氛围下,对其进行不同时间(15s、30s和60s)的后沉积退火(PDA),退火温度为650℃.结果表明,随着退火时间的增加,O_2中样品的EOT、栅极泄漏电流(I_g)以及平带电压(V_(fb))均未出现明显变化,而N_2中样品的EOT在退火时间为30s时急剧下降,V_(fb),也有所上升.最终,退火温度650℃退火时间30 s为最佳退火条件,此时EOT为0.88 nm,满足14/16 nm技术节点的要求.

With the further miniaturization of nano-devices, Hf-based high-k materials are unable to meet the need of development. The introduction of new high-k materials is required. In order to reduce the equivalent oxide thickness （F, OT） of nano-devices, HtO2 was doped with Al and subjected to post-deposi- tion annealing（PDA ） at ditterent times （15 s, 30 s and 60 s） under N2 and 02 atmosphere, respectively, and the annealing temperature is 650 ℃. The results show that with the increase of annealing time, the EOT, gate leakage current （Ig）, and flatband voltage （Vfb） of the sample in 02 did not change significant- ly, while the F, OT of the sample in N2 decreased sharply when the PDA time is 30 s. And Vfb rose too. In the final process, annealing temperature 650 ℃ and annealing time 30 s are the best annealing condition, and the F, OT is 0.88 nm, which satisfies the requirements of the 14/16 nm technology node.