1/f CHANNEL NOISE AT HIGH DRAIN CURRENT IN MOS TRANSISTORS

Abstract

Communicated by L. K. J. VandammeOn account of low resistivity contacts and of a newly developed device, the investigation of the 1/f noise at high drain current has been made possible. Therefore, it has been acknowledged that the correlated carrier number and mobility fluctuations model were not able to satisfactorily explain the 1/f noise within this particular region. Indeed, the fundamental mobility fluctuations were also generating 1/f fluctuations and were furthermore, taking over at high biases. It eventually came to light that the fundamental mobility fluctuations along with the sole oxide charge fluctuations were accurately modeling the noise all over the measurement range, allowing us to notice that the fundamental mobility fluctuations were generating the same amount of 1/f fluctuations as the induced mobility added to the cross correlated ones.

Importance of Si surface flatness to realize high-performance Si devices utilizing ultrathin films with new material system

“…9(b). The MOSFET fabricated on the flat Si surface has lower normalized noise spectral density which is a consequence of the strong influence of the surface roughness scatterings and D it [42,43]. Further decrease of 1/f noise would be possible by reducing the Si surface roughness to the level of atomically flat, and it will progress the ultralow noise MOSFET applications even with the high-k gate insulator.…”

Performances of accumulation-mode n- and p-MOSFETs on Si(110) wafers

“…The strength between the induced mobility fluctuations and the fluctuations of the oxide charge is expressed by the Coulomb parameter α, and the α values are generally found close to 10 4 V•s=C for electrons and 10 5 V•s=C for holes in silicon MOSFETs. 6,[40][41][42][43][44] The sign before α can be negative or positive, depending on not only the type of device (n or p) but also the type of defects, although the plus sign is almost always used for both n-and p-MOSFETs. In Eq.…”

“…Actually, the ΔQ ox − Δμ ind formalism has been extensively employed for several decades and has until now accurately modeled the noise in MOSFETs. Nevertheless, recent works 6,42,49) strongly suggest that a second uncorrelated noise source located inside the channel might also be generating 1=f noise in addition to the traps in the ΔQ ox − Δμ ind formalism. This second noise source is in the form of the fundamental fluctuations of mobility and conforms to the Hooge theory, 50) which was proposed more than 50 years ago and gradually set aside in favor of the ΔQ ox − Δμ ind theory.…”