Influence of multi-deposition multi-annealing on time-dependent dielectric breakdown characteristics of PMOS with high-/metal gate last process

• 作者: 叶甜春 张淑祥 徐昊 朱慧珑 杨红 王文武 王晓磊 王艳蓉 祁路伟 罗维春 赵超 闫江 陈大鹏
• 来源期刊: 中国物理B（英文版）
• 关键词: high-k/metal gate time dependent dielectric breakdown multi-deposition multi-annealing
• 年，卷（期）: 2015,（11）
• 页码范围: 117306-1-117306-4
• 页数: 1页
• 语种: 英文
• DOI: 10.1088/1674-1056/24/11/117306

摘要

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 depo-sition/annealing (D&A) cycles, the D&A time, and the total annealing time. The results show that the increases of the number of D&A cycles (from 1 to 2) and D&A 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 D&A cycles (such as 4 cycles) make the equivalent oxide thickness (EOT) increase by about 1 ?A and the TTF of PMOS worsen. Moreover, different D&A times and numbers of D&A cycles induce different breakdown mechanisms.