Effects of high-K dielectrics with metal gate for electrical characteristics of 18nm NMOS device

Abstract

This paper presents a systematic study of various high-K materials on metal gate MOSFET for 18nm NMOS. From the study, we find a suitable combination materials between the high-K and metal gate, which has beneficial effects on the electrical characteristics of 18nm NMOS. The device shows a good improvement on its result of sub-threshold leakage current, I OFF, and drive current, I ON for different dielectric constants (k). The virtual design and fabrication of the device were performed by using Athena module. While electrical characteristic performance was simulated by using Atlas module of SILVACO software. Physical models of the 18nm NMOS were used for simulation from Al 2 O 3 , HfO 2 , and TiO 2 as the material gate dielectric, with TiSi 2 as the metal gate, which provide higher physical thickness that able to reduce the sub-threshold leakage current I OFF . Thus, excellent dielectric properties such as high-K constant, low I OFF , higher I ON , threshold voltage V TH , and electrical characteristics were demonstrated. From the simulation results of I ON and I OFF, it was proven that HfO 2 is the best dielectric material with combination of metal gate, TiSi 2 .

Enhanced performance of 19 single gate MOSFET with high permittivity dielectric material

“…The ION values resulted from the simulation shows larger values obtained (587.6µA/µm) as opposed to estimated values (456µA/µm) for a device that has WSix as metal gate whereas the simulation results for IOFF are lower (1.92pA/µm) than forecasted value (20pA/µm) is also from the device that has WSix as metal gate. The decent performance of design MOSFET is when IOFF equal to zero ampere and higher of ION value [2]. Hence, it is concluded that both high-K materials are attuned with metal gate and compatible with device transistor.…”

“…Besides, the sufficient barrier height is also obtainable due to the heat of formation and bandgap for HfO2 is 271 Kcal/mol and 5.68eV respectively and is high enough. HfO2 is thermodynamically stable with silicon substrate, high dielectric constant (~25), impurity diffusion resistance due to its high density (9.68g/cm3), along with similar lattice parameter to that of Si with a small lattice misfit (<5%) [2].…”

“…In order to overcome this problem, scholars are concentrating on the metal gate with high-K materials that is capable to be incorporated in MOSFET flow [1]. Despite that, there are several high-K materials that holds dielectric constant that is either too low or high for which may not be an appropriate of choice for alternative gate dielectric [2]. Therefore, substituting the SiO2 with high-K materials permits an amplification of gate capacitance.…”

Comparative high-k material gate spacer impact in DG-FinFET parameter variations between two structures

“…The reduction to nanometer regime has triggered the short channel effects to arise which degrades the system performance and reliability. Therefore, a fin-shaped field effect transistor (FinFET) of 16nm technology is designed along with the performance of the transistor that is improved in relation to the Moore's Law [3]. The devices performance may have been degraded via scaling process for the transistor miniaturization.…”

Influence of optimization of control factors on threshold voltage of 18 nm HfO2/TiSi2 NMOS

“…If the VTH value is not achieved, it will affect the whole system of the device and worst case, the device will not function at all. It is caused the doping fluctuations [2] Based on previous research, there are two ways to solve the problems above with the good combination between high-k dielectric and metal gate that is between HfO2 and TiSi2 [3]. Another solution is the optimization on process parameter using L27 Taguchi method.…”