Low-Frequency (1∕f) Noise Performance of n- and p-MOSFETs with Poly-Si∕Hf-Based Gate Dielectrics

Abstract

The low-frequency ͑LF͒ noise performance of n-and p-channel metal-oxide-semiconductor field-effect transistors ͑MOSFETs͒ with different Hf-based gate oxides, deposited by metallorganic chemical vapor deposition ͑MOCVD͒ on the same interfacial oxide layer and using polysilicon ͑poly-Si͒ as a gate material has been investigated. Independent of the gate oxide, the LF noise spectra of n-and p-MOSFETs are predominantly of the 1/f ␥ type, with the frequency exponent ␥ close to 1. For nMOSFETs, the noise spectral density of HfO 2 devices is two orders of magnitude higher than for SiON or Hf x Si 1−x ON ͑silicates͒, where 0 Ͻ x Ͻ 100%, most likely due to trapping by defects in the high-k layer. For the silicates with different x, no significant differences are noticed for n-and p-MOSFETs. It is shown that the noise characteristics behave as can be expected for a number fluctuations mechanism. The extracted volume and surface trap densities are significantly higher for pure HfO 2 than for the Hf x Si 1−x ON devices. In the latter case, trap densities comparable with the values for the SiON reference transistors are obtained. Hooge's parameter ␣ H , as an alternative figure of merit, shows that the devices with MOCVD HfO 2 gate dielectric have the noisiest performance, while Hf x Si 1−x ON MOSFETs yield the lowest ␣ H , even better than for SiON.

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

“…Many institutions have reported so far the Si surface flattening process [17,18,19,20], and MOSFETs with atomically flat interface at Si/gate insulator show higher performances than those with conventional devices [21,22,23,24]. The 1/f noise in MOSFETs with Si/high-k gate stacks has also been reported [25,26]. However, there have been few report for the influence of Si surface roughness on the high-k gate insulator formation.…”

Investigation of Low‐Frequency Noise Characterization of 28‐nm High‐k pMOSFET with Embedded SiGe Source/Drain

“…However, it should be noted that the 1/ performance of our HK pMOSFETs will be probably worse than counterparts with traditional SiO 2 insulator [14]. This is owing to the complexity of HK process that led to the higher volume trap densities in gate stacks [29].…”

Entropy of Measurements of Electric and Non-eleCtric Systems Fluctuating Parameters

“…During experiments there is a controversial attitude towards the fluctuations: on one hand, own fluctuations of both voltage and current of the measuring electronic equipment, determine the threshold of sensitivity, especially during measurement of small values of the investigated parameters (it is worth mentioning that the ways to reduce fluctuations are being developed). On the other hand, fluctuations represent independent interest, since they are the basis of numerous physical [1][2][3][4][5][6][7][8][9][10] . Most of them are based on the analysis of processes at the microscopic level: fluctuations of concentration of charge carriers [3,10] ; fluctuations of mobility of charge carriers [2,7] ; capture of charge carriers by the surface energy traps [5] etc.…”

“…On the other hand, fluctuations represent independent interest, since they are the basis of numerous physical [1][2][3][4][5][6][7][8][9][10] . Most of them are based on the analysis of processes at the microscopic level: fluctuations of concentration of charge carriers [3,10] ; fluctuations of mobility of charge carriers [2,7] ; capture of charge carriers by the surface energy traps [5] etc. Some hypothesis explain increase of energy spectrum of fluctuations if frequency decreases at the macroscopic level -as a result of nonequilibrium state of the investigated system [11,12] .…”