Electric-field-dependent charge delocalization from dopant atoms in silicon junctionless nanowire transistor

Abstract

We study electric-field-dependent charge delocalization from dopant atoms in a silicon junctionless nanowire transistor by low-temperature electron transport measurement. The Arrhenius plot of the temperature-dependent conductance demonstrates the transport behaviors of variable-range hopping (below 30 K) and nearest-neighbor hopping (above 30 K). The activation energy for the charge delocalization gradually decreases due to the confinement potential of the conduction channel decreasing from the threshold voltage to the flatband voltage. With the increase of the source-drain bias, the activation energy increases in a temperature range from 30 K to 100 K at a fixed gate voltage, but decreases above the temperature of 100 K.

Device physics and design of FD-SOI JLFET with step-gate-oxide structure to suppress GIDL effect*

“…Since the increment increase of T Toxide reduces the surface hole density under the tunnel oxide, the GIDL in SGO JLFET is inhibited and then I off decreases as discussed above. With the increase of T Toxide , the value of SS gradually decreases from 190 mV/dec to 84 mV/dec, and the I on /I off ratio increases from 1.3×10 4 to 4.9×10 4 as shown in Fig. 8.…”

“…results in a wider tunnel path at V GS = 0 V, and restricts GIDL more significantly. So, when L Toxide is changed from 5 nm to 10 nm, the off-state current I off of SGO JLFET at V GS = 0 V decreases from 5×10 −8 A/µm to 1.23×10 −8 A/µm with influence on the on-state current weakening, thus, reducing the SS from 109 mV/dec to 84 mV/dec and increasing the I on /I off ratio from 1.2×10 4 to 5×10 4 as shown in Fig. 10.…”

“…Scaled down into nanometers, conventional Si MOSFETs are facing the problems of forming ultra-steep doping profile in p-n junctions, [1][2][3][4] and field-effect transistors (FETs) without junctions, i.e., junctionless FETs (JLFETs) were proposed to eliminate the stringent requirement. [5][6][7][8][9][10] Unlike "regular" p-n junction-based FET, the JLFET usually has the same uniform doping concentration in the source, channel and drain region.…”

Bias-dependent hole transport through a multi-channel silicon nanowire transistor with single-acceptor-induced quantum dots

“…27 Unlike in IM transistors, carriers in JNTs transport through the accumulation-mode (AM) body channel rather than the IM surface layer, reducing the impact of the channel edge roughness on the transport, thus resulting in a stronger quantum-confinement effect on the carriers. 28–30 Moreover, the electric field E C perpendicular to the current flow in a JNT is lower than that in an IM transistor. In particular, E C decreases close to zero at the center of the channel in a JNT.…”

Enhancement of off-state characteristics in junctionless field effect transistor using a field plate

“…[4,5] To overcome this limitation, various alternative devices are being proposed, and a new class of field effect device called the junctionless field-effect transistor (JLFET) has attract lots of research attention in recent years. [6][7][8][9][10][11][12][13][14] The basic structure of a JLFET consists of a uniformly highly doped silicon channel controlled by at least an on gate electrode. Unlike "regular" junction-based FETs, in JLFET, both the source and the drain have the same type of doping as the channel, and there is no pn junction.…”