In Shik Han

Conduction Mechanism and Reliability Characteristics of a Metal–Insulator–Metal Capacitor with Single ZrO2 Layer

In this paper, the electrical characteristics and reliability of ZrO2-based metal–insulator–metal (MIM) capacitors are investigated. High capacitance density of 15.3 fF/µm2 was achieved for ZrO2 MIM capacitors, which is acceptable for the reported MIM capacitors. Schottky emission at the low field region is not a dominant mechanism, and Frenkel–Poole emission is the dominant mechanism at the high electric field region. The extracted dynamic constant and trap energy level were 4.013 and 0.963 eV, respectively. The reduced trap energy level with increasing electric field is due to a rise in the field-induced barrier-lowering effect. The variation of α as a function of stress time under constant voltage stress (CVS) gradually decreases, while the variation of ΔCstress/C0 under CVS increases because the generation of new dipoles in the high-κ dielectric under CVS may cause charge trapping in the high-κ dielectric.

Comparison of Multilayer Dielectric Thin Films for Future Metal–Insulator–Metal Capacitors: Al2O3/HfO2/Al2O3 versus SiO2/HfO2/SiO2

In this paper, two kinds of multilayered metal–insulator–metal (MIM) capacitors using Al2O3/HfO2/Al2O3 (AHA) and SiO2/HfO2/SiO2 (SHS) were fabricated and characterized for radio frequency (RF) and analog mixed signal (AMS) applications. The experimental results indicate that the AHA MIM capacitor (8.0 fF/µm2) is able to provide a higher capacitance density than the SHS MIM capacitor (5.1 fF/µm2), while maintaining a low leakage current of about 50 nA/cm2 at 1 V. The quadratic voltage coefficient of capacitance, α gradually decreases as a function of stress time under constant voltage stress (CVS). The parameter variation of SHS MIM capacitors is smaller than that of AHA MIM capacitors. The effects of CVS on voltage linearity and time-dependent dielectric breakdown (TDDB) characteristics were also investigated.

Time-dependent dielectric breakdown of La2O3-doped high-k/metal gate stacked NMOSFETs

Time-dependent dielectric breakdown (TDDB) characteristics of La2O3-doped high-k dielectric in Hf-based high-k/TaN metal gate stack were studied. Unlike the abrupt breakdown in the conventional SiO2 , dielectric breakdown behaviors of La-incorporated HfON and HfSiON dielectrics show progressive breakdown characteristics. Moreover, the extracted Weibull slope beta of breakdown distribution is in the range of 0.87-1.19, and it is independent on capacitor areas and stress conditions. Moreover, field dependence of TBD and stress-induced leakage current strongly suggest that the E-model is more applicable to explain in TDDB of La-incorporated high-k dielectric in Hf-based high-k/metal gate stack structure.

A comprehensive and comparative study of interface and bulk characteristics of nMOSETs with la-incorporated high-k dielectrics

Reported herein is a comprehensive and comparative study on NMOSFETs with HfLaSiON and HfLaON gate dielectric with an equivalent oxide thickness (EOT) of 0.9 nm (Tinv~1.2 nm). Digital and analog performances as well as reliability characteristics are compared in detail. It is shown that HfLaSiON has a strong relationship with the interface characteristics due to low barrier height, while HfLaON with the bulk trap characteristics due to greater bulk trap density.

Test Structures for Accurate UHF C-V Measurements of Nano-Scale CMOSFETs with HfSiON and TiN Metal Gate

Test structures for accurate UHF capacitance-voltage (C-V) measurements of high performance CMOSFETs with Hf-based high-k dielectric and TiN metal gate are analyzed. It is shown that series resistance or substrate resistance between the channel region and body contact plays a role in UHF C-V measurements. The substrate resistance beneath the gate region also impacts accurate UHF C-V measurements. Therefore, minimization of series resistance through short gate lengths with a minimum distance between the source/drain and body contact is highly desired for an accurate evaluation of gate dielectric thickness using UHF C-V measurements.

Dependency of 1/f noise on initial oxidation method in nano-CMOS technology

In this paper, it is presented that flicker (1/f) noise of ultra thin gate oxide can be improved by initial oxidation and subsequent plasma nitridation(PN). PN which raises Nitrogen peak upward from the Si/Oxide interface to gate polysilicon/Oxide interface is adopted mainly to improve the life time such as Negative-Bias Temperature Instability (NBTI) and hot carrier in Nano CMOS technology. Three different types of initial oxidation prior to plasma nitridation are investigated. One is slow thermally grown oxide(STO) in very small Oxygen ambient, another is rapid thermally grown oxide(RTO) and the other is grown in Nitrous oxygen ambient (NO). Oxide thickness of all splits is about 14.5< Then, it is shown that STO has the lowest drain current noise power (Sid) among the splits. The interface trap densitie (Dit) of each oxide is characterized using charge pumping method. Finally, we reached a conclusion that the 1/f noise can be significantly reduced by initial STO and Plasma Nitridation in Nano CMOS technology.