Effects of annealing gas species on the electrical properties and reliability of Ge MOS capacitors with high-k Y 2O 3 gate dielectric

In this work, Ge MOS capacitors with Y 2O 3 gate dielectric were fabricated. The effects of annealing in N 2, NH 3 O 2 or NO ambient were investigated. Experimental results demonstrated that the NO annealing could improve both electrical properties and reliability of Ge MOS devices with Y 2O 3 dielectric. On the other hand, the NH 3 annealing resulted in H-related traps while the O 2 annealing suffered from extra GeO x growth, thus both degrading the performance of the devices. ©2009 IEEE.published_or_final_versionThe IEEE International Conference on Electron Devices and Solid-State Circuits (EDSSC 2009), Xi'an, China, 25-27 December 2009. In Proceedings of EDSSC, 2009, p. 243-24

Improvement on 1/f noise properties of nitrided n-MOSFET's by backsurface argon bombardment

The 1/f noise properties of nitrided n-MOSFET's bombarded by low-energy (550 eV) argon-ion beam are investigated. It is found that after bombardment, 1/f noise, and its degradation under hot-carrier stress are reduced, and both exhibit a turnaround behavior with bombardment time for a given ion energy and intensity. The physical mechanism involved is probably enhanced interface hardness resulting from bombardment-induced stress relief in the vicinity of the oxide/Si interface. Moreover, from the frequency dependence of the noise, it is revealed that the nitrided devices have a nonuniform trap distribution increasing toward the oxide/Si interface which can be modified by the backsurface bombardment.published_or_final_versio

Interface properties of NO-annealed N2O-grown oxynitride

The oxide/Si interface properties of gate dielectric prepared by annealing N2O-grown oxide in an NO ambient are intensively investigated and compared to those of O2-grown oxide with the same annealing conditions. Hot-carrier stressings show that the former has a harder oxide/Si interface and near-interface oxide than the latter. As confirmed by SIMS analysis, this is associated with a higher nitrogen peak concentration near the oxide/Si interface and a larger total nitrogen content in the former, both arising from the initial oxidation in N2O instead of O2.published_or_final_versio

Dynamic-stress-induced enhanced degradation of 1/f noise in n-MOSFET's

AC-stress-induced degradation of 1/f noise is investigated for n-MOSFET's with thermal oxide or nitrided oxide as gate dielectric, and the physical mechanisms involved are analyzed. It is found that the degradation of 1/f noise under ac stress is far more serious than that under dc stress. For an ac stress of VG = 0 approx. 0.5 VD, generations of both interface state (ΔDit) and neutral electron traps (ΔNet) are responsible for the increase of 1/f noise, with the former being dominant. For another ac stress of VG = 0 approx. VD, a large increase of 1/f noise is observed for the thermal-oxide device, and is attributed to enhanced ΔNet and generation of another specie of electron traps, plus a small amount of ΔDit. Moreover, under the two types of ac stress conditions, much smaller degradation of 1/f noise is observed for the nitrided device due to considerably improved oxide/Si interface and near-interface oxide qualities associated with interfacial nitrogen incorporation.published_or_final_versio

1/f noise in n-channel metal-oxide-semiconductor field-effect transistors under different hot-carrier stresses

Degradation mechanisms contributing to increased 1/f noise of n-channel metaloxide-semiconductor field-effect transistors (n-MOSFETs) after different hot-carrier stresses are investigated. It is demonstrated that for any hot-carrier stress, the stress-induced enhancement of 1/f noise is mainly attributed to increased carrier-number fluctuation arising from created oxide traps, while enhanced surface-mobility fluctuation associated with electron trapping at preexisting and generated fast interface states and near-interface oxide traps is also responsible under maximum substrate- and gate-current stresses. Besides thermal-oxide n-MOSFETs, nitrided-oxide devices are also used to further support the above analysis. © 1999 American Institute of Physics.published_or_final_versio

Electrical properties of different NO-annealed oxynitrides

This journal issues contain proceedings of the 2nd International Conference on Amorphous and Crystalline Insulating Thin Films II ... 1998Performances of gate dielectrics prepared by double-nitridation in NO and N2O are investigated. Stronger oxide/Si interface bonding, less charge trapping and larger charge-to-breakdown are observed for such gate dielectrics than singly NO-nitrided gate dielectric. The physical mechanisms behind the findings are attributed to larger nitrogen peak concentration located almost at the oxide/Si interface and total nitrogen content near the oxide/Si interface of these gate dielectrics.postprin

Enhanced off-state leakage currents in n-channel MOSFET's with N2O-grown gate dielectric

This paper reports on the off-state drain (GIDL) and gate current (Ig) characteristics of n-channel MOSFETs using thin thermal oxide (OX), N2O-nitrided oxide (N2ON), and N2O-grown oxide (N20G) as gate dielectrics. Important phenomena observed in N20G devices are enhanced GIDL and Ig in the low-field region as compared to the OX and N20N devices. They are attributed to heavy-nitridation-induced junction leakage and shallow-electron-trap-assisted tunneling mechanisms, respectively. Therefore, N2ON oxide is superior to N20G oxide in leakage-sensitive applications.published_or_final_versio

Electrical performance and reliability of n-MOSFETs with gate dielectrics fabricated by different techniques

In this paper, electrical characteristics and reliability of n-MOSFETs under DC/AC stress are investigated and results are compared among the devices with gate dielectrics fabricated by different techniques. From the results it is concluded that N2O nitridation is a more promising technique to incorporate nitrogen into gate oxide than NH3 nitridation both from the point of view of electrical performance and stability under CHCS and dynamic stress.published_or_final_versio

Effects of wet N 2O oxidation on interface properties of 6H-SiC MOS capacitors

Oxynitrides were grown on n- and p-type 6H-SiC by wet N 2O oxidation (bubbling N 2O gas through deionized water at 95°C) or dry N 2O oxidation followed by wet N 2O oxidation. Their oxide/SiC interfaces were investigated for fresh and stressed devices. It was found that both processes improve p-SiC/oxide but deteriorate n-SiC/oxide interface properties when compared to dry N 2O oxidation alone. The involved mechanism could be enhanced removal of unwanted carbon compounds near the interface due to the wet ambient, and hence a reduction of donor-like interface states for the p-type devices. As for the n-type devices, incorporation of hydrogen-related species near the interface under the wet ambient increase acceptor-like interface states. In summary, the wet N 2O oxidation can be used for providing comparable reliability for n- and p-SiC MOS devices, and especially obtaining high-quality oxide-SiC interface in p-type MOS devices.published_or_final_versio

A comparison between NO-annealed O2- and N2O-grown gate dielectrics

Qualities of oxynitrides prepared by annealing O2- and N2O-grown oxides in NO ambient are investigated. Harder oxide/Si interface, less charge trapping and higher charge-to-breakdown characteristics are observed in NO-annealed N2O-grown (N2ONO) oxynitride than NO-annealed O2-grown (O2NO) oxynitride. The involved mechanism lies in higher interfacial nitrogen concentration and total nitrogen content in N2ONO oxynitride than O2NO oxynitride for the same anneal temperature and time.published_or_final_versio