Lumped model analysis of the low frequency generation noise in gold-doped silicon junction-gate field-effect transistors

Generation-Recombination-Trapping at Interface Traps In Compact MOS Transistor Modeling

“…The MOS circuit operation properties affected by the presence of electron-hole traps at the SiO 2 /Si interface of the MOS transistors can be estimated as follows: (i) Average or DC standby power dissipation is specified by the base terminal leakage current, the portion of which related to the interface traps is given by I B =I GRT (e ns e ps ) 1/2 N IT ; (ii) Operation lifetime of the MOS transistor in logic and analog MOS circuits is specified by the MOS transistor gate threshold voltage shift of about 1mV which is given by V GBth qn it (r,t)/C ox~1 mV where C ox is the specific capacity (F/cm 2 ) of the gate dielectric C ox = ox /X ox , and ox is the permittivity and X ox is the electrical thickness of the gate dielectrics; (iii) Endurance of the nonvolatile MOS memory circuits (program and data flash memory chips) using memory MOS transistor (floating polycrystalline silicon gate and nitrided, SONOS, and other charge-storage-dielectric gate [12,13,14].) is also specified by the MOS transistor gate threshold voltage shift, at much higher magnitudes, about 1V, given by V GBth qn it (r,t)/C ox~1 V, under much higher electrical stress during the write-program and erase operations than the logic switching and analog amplification; and (iv) RF and HF noise [15][16][17][18][19][20][21][22][23][24][25][26] from trapping and tunneling to interface and oxide traps with the multi-component or multi-time-constant GRT 1/(1+ 2 2 ) [16] and 1/f [15,25] noise spectra, is specified by a noise equivalent input voltage per unit band-width of about 1 V·Hz 1/2 from random emission and capture or trapping of electrons and holes at the interface traps and band-trap and trap-trap tunneling transitions given by a gate equivalent input noise voltage of V gn qn it (r,t)/C ox~1 V and a characteristics noise frequency of grt = 1 = (c ns N S + e ns + c ps P S + e ps )P T'T < 1Hz to > 10 12 Hz, where P T'T is the transition probability rate, an exponential attenuation factor, from electron and hole trap-band tunneling transitions between the nearinterface oxide traps and the conduction and valence band states, or the less likely trap-trap tunneling transitions between a near-interface trap and a at-theinterface trap. {See sections 363n on pp.…”

Influence of the doping profile and deep level trap characteristics on generation-recombination noise

“…8 Another element previously considered was the type of shallow impurity profile in the junctions of junction field effect transistors ͑JFETs͒ used in g-r noise evaluation. 9 That work concludes that step-step impurity profiles generate less noise than graded profiles. Since then, mostly step-step profiles have been analyzed and the contribution of depletion regions of the P layers in an n-channel JFET has been neglected.…”

“…4, the noise evaluated in the bottom gate-channel junction surpasses the noise calculated in the top one for both profiles. 9 However, a different behavior appears between the two junctions. While in the top junction the noise evaluated with the uniform profile is slightly greater than with the implanted one, the opposite trend was found in the bottom junction.…”

“…Apart from the known fact that the bottom junction can dominate the noise spectral density due to the asymmetry of the structure, 9 we have analyzed another situation that enhances the importance of this junction, namely, the presence of a high concentration of deep levels. Moreover, another fact that is not yet clear is whether the main contribution to the total noise is located in the channel ͑N region͒ or in the substrate ͑P region͒ of the bottom junction.…”

Influence of the position of deep levels on generation-recombination noise

“…Recently, the possibility of there being noise spectra different from the usual Lorentzians for an individual deep level 4 has been pointed out. In fact, gentler slopes have been found in experimental data 10,11 from gold doped devices.…”