篇題：First Demonstration of Multi-VT Stacked Ge0.87Sn0.13 Nanosheets by Dipole-Controlled ALD WNxCy Work Function Metal with Low Resistivity and Thermal Budget ≤ 400 ℃
文章出處：
Symposia on VLSI Technology and Circuits (VLSI), T15-3, 2021.
作者：Chung-En Tsai, Yu-Rui Chen, Chien-Te Tu, Yi-Chun Liu, Jyun-Yan Chen, and C. W. Liu*
任職單位及部門：台灣大學電子工程學研究所
Dipole-controlled WNxCy work function metal (WFM) by plasma-enhanced atomic layer deposition (PEALD) is integrated with stacked
GeSn nanosheet transistors to enable multi-VT with a wide tunability of 510 mV at the low process temperature ≤ 400 °C. The effective work function
(EWF) of WNxCy is modulated by the relative thicknesses of pWFM and nWFM while maintaining the constant total thickness. EWF tuning of 500
meV around Si midgap is obtained, and the best achievable resistivity of ALD WNxCy is 990 μΩ-cm, much lower than industrial ALD TiAl value
(2000 μΩ-cm). Multi-VT stacked Ge0.87Sn0.13 nanosheets are demonstrated by controlling the different group electronegativity and dipole strength at
nWFM/WNxCy:O interface.
文章摘要：
利用偶極控制電漿輔助原子層沉積之低電阻率與≤400℃熱預算之WNxCy功函數金屬(WFM)整合於堆疊鍺錫奈米片電晶體，可實現具有510mV大範圍之多臨界電壓。藉由
改變pWFM和nWFM的相對厚度，WNxCy的等效功函數可調變達500meV，並具有990μΩ-cm之電阻率，遠低於業界原子層沉積之TiAl (2000μΩ-cm)。通過控制
nWFM/WNxCy:O界面處的不同基團電負度和偶極強度，可實現多臨界電壓之堆疊鍺錫奈米片。