III V MOSFETs

This paper presents a new technique to improve frequency performance of CMOS ring oscillator. It is based on the addition of MOS transistor to boost switching speed of the oscillator delay cell. The method can be used for simple and differential oscillator and offers a simple way to implement frequency tuning without introduction of any additional phase noise. Using 0.35 μm CMOS technology, simulation results show that applying the technique to the simple ring oscillator allows a frequency oscillation improvement of 80%. Also, simulations show that frequency improvement can reach 300 % if the technique is associated to a positive feedback.

In this work, room temperature oxidation of GaAs was investigated using ion beam oxidation (mO). In lBO, an ion beam is used to introduce oxygen athermally into the substrate, in this case GaAs. GaAs bonds are broken upon collision with the ions, making gallium and arsenic atoms readily available to react with the oxygen species. Ion beam oxidation of GaAs at room temperature was studied as a function of oxygen ion energy between 500 and is keY. The ion beam oxidized GaAs was characterized in situ by Auger electron spectroscopy (AES) and ex situ with x-ray photoelectron spectroscopy (XPS) for accurate determination of the film chemical composition. Below 1 keY, a thin oxide film is formed: it is composed of Ga 2 0 3 and AS 2 0 3 with almost no metallic arsenic, and presents insulating properties. As the ion energy increases, preferential sputtering of As and decomposition of AS 2 0 3 increase and prevent formation of an insulating film. No damage was detected by Rutherford backscattering spectrometry (RES) combined with ion channeling, in the substrate subjected to IBO below 1 keY.

The structural and chemical details of GeO 2 / Ge layers grown on In 0.15 Ga 0.85 As substrates by molecular beam deposition were studied in situ by diffraction and spectroscopic techniques. The formation of semiconductor-oxygen bonds at the Ge/ In 0.15 Ga 0.85 As interface, which may play a decisive role in dictating the quality of the Ge passivation, was assessed after using two different surface preparations, namely Ar sputtering and atomic hydrogen cleaning.

III--V junctionless gate-all-around (GAA) nanowire MOSFETs (NWFETs) are experimentally demonstrated for the first time. Source/drain resistance and thermal budget are minimized by regrowth using metalorganic chemical vapor deposition instead of implantation. The fabricated short channel (Lg = 80 nm) GaAs GAA NWFETs with extremely scaled NW width (WNW= 9 nm) exhibit excellent gm linearity at biases as low as 300 mV, characterized by the high third intercept point (2.6 dbm). The high linearity is insensitive to the bias conditions, which is favorable for low power applications.

... at 300 K. The total power input from the ion beam was at all times well below the limit for ion beam heat-ing-From the present description of ÍBO, it can be seen that the main interest of IBO is to allow oxidation at very low 1036 temperatures. Indeed, oxidation of Si has been ...