学术报告

New Insights In Hf Based High-k Gate Dielectrics in MOSFETs

 

李名复教授

新加坡国立大学

报告人简介

Graduated from the Department of Physics, Fudan University , Shanghai

Professor in the Electrical and Computer Engineering Department of the National University of Singapore

A senior member technical staff at the Institute of Microelectronics, Singapore

Published over 300 research  papers, and two books, including " Modern Semiconductor Quantum Physics" (World Scientific in 1994 ).

Served on several international program committees and advisory committees in semiconductor conferences in Canada, China, Germany, Japan, Singapore, Taiwan China and USA .

研究领域:

l         High k gate dielectric/metal gate

l         Nano CMOS device reliability Physics

l         Metal –Semiconductor Schottky contact and its application in CMOS transistors

l       Quantum modeling and simulation of nano CMOS devices and  investigation of CMOS compatible emerging devices for the future integrated circuit applications

 

报告摘要:

I.      Two different traps (fast and slow) in HfO2 gate dielectric are identified. For the slow traps, the negative U (-U) property of trap is proposed and confirmed by the first principle calculation. Each trap can trap two electrons or two holes and lower the trap energy due to a large lattice relaxation. The observed experimental result of reduction in slow component of bias temperature instability (BTI) degradation with an increase in stress frequency can be simulated with excellent agreement, based on the concept of -U. A fast BTI component is also observed. The fast dynamic BTI degradation is increased with an increase in stress frequency. It is due to the existence of fast traps and can be simulated by the conventional trapping/de-trapping equations.

II.   Mixing Ta and La into HfO2 to form HfTaO and HfLaO gate dielectric have been studied systematically. Comparing to the HfO2 gate dielectric, the HfTaO and HfLaO have the advantages of much higher crystallization temperature, much lower charge trapping as well as the BTI degradation,  and increased channel mobility.  In addition, variation of La concentration in HfLaO/TaN or HfLaO/HfN gate stack can effectively  tune the metal work function continuously from mid gap to 4eV. Possible physical explanation  for these interesting properties are discussed.   

 

报告时间:419(周三)下午330

报告地点:物理楼二楼会议室
 
 

 

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