Electrical Analysis and Investigation with Dynamic Negative and Positive Bias Stress of Hf1-xZrXO2/Metal Gate for P-MOSFETs

• Main Authors: Wu, Chi-Wei, 吳啓維
• Other Authors: Sze, Simon M.
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/24674026365770770688

碩士 === 國立交通大學 === 電子研究所 === 100 === The electrical characteristics and reliability of Hf1-xZrxO2 gate metal-oxide- semiconductor field effect transistors (MOSFETs) are investigated by analyzing experimental data from DC Id-Vg , and charge pumping measurements. We have found that higher mobility(μ), lower threshold voltage (Vth), and improved charge trapping without a significant increase in leakage current can be obtained when we increase the Zirconium content in metal gate for p-MOSFETs. This is because ZrO2 can stabilize the tetragonal phase and enhance the κ value in Hf1-xZrxO2 devices. Because of the increased VT and GIDL, we believe that hole trapping is the dominate effect under AC dynamic NBS. The gate current is found to be holes going from the channel to the gate, not electrons going from the gate to the channel. In addition, the gate leakage current is due to a series of Frenkel-Poole and tunneling current. Under Vg<VT condition, with the electric field increased, the gate leakage of Frenkel-Poole to tunneling dominant, moreover under Vg>VT condition, with the electric field increased, the gate leakage of tunneling to Frenkel-Poole dominant. And then learned that the gate current hump conditions of Frenkel-Poole>tunneling. Finally, the reliability analysis the incorporation of Zirconium or absence of components in p-MOSFETs allows the incorporation of Zirconium gate leakage become smaller, and thus inhibition of Frenkel-Poole. Afetr dynamic PBS, electrons from the substrate flow to the gate; meanwhile, cause the interface traps and the bulk traps. In the DC measurement, the bulk trap of the electron compensate for the actual measured, therefore its threshold voltage shift than the charge pumping measured threshold voltage shift is much smaller.