Broadband single-electron tunneling transistor

Abstract

A microfabricated electrontunneling accelerometer as a directional underwater acoustic sensor AIP Conf.A single-electron tunneling transistor has been directly coupled on-chip to a high electron mobility transistor. The high electron mobility transistor ͑HEMT͒ is used as an impedance matching circuit with a gain close to unity. The HEMT transformed the 1.4 M⍀ output impedance of the single electron tunneling ͑SET͒ transistor by two orders of magnitude down to 5 k⍀, increasing its bandwidth to 50 kHz. This circuit makes it possible to observe the motion of individual electrons at high frequencies. The requirements for the bandwidth in high frequency applications is discussed.

Single-electron current sources: Toward a refined definition of the ampere

“…Bandwidths up to 700 kHz have been achieved by utilizing a high-electronmobility transistor (HEMT) amplifier with a low impedance output at the sample stage (Pettersson et al, 1996;Visscher et al, 1996). The dissipated power at the HEMT in these studies was 1-10 W depending on the biasing, which can easily result in overheating of the electrometer and/or the coupled single-electron device.…”

“…In practice, the capacitance of the biasing leads and the input capacitance of the preamplifier dominate. When the preamplifier is located at room temperature as in the pioneering experiments (Fulton and Dolan, 1987;Kuzmin et al, 1989), the wiring necessarily contributes a capacitance of the order of 0.1-1 nF and henceforth limits the readout bandwidth to the kilohertz range (Pettersson et al, 1996;Visscher et al, 1996). Readout by a current amplifier from a voltage-biased SET avoids the RC cutoff on the gain, but the usable bandwidth is not substantially altered as current noise increases at high frequencies where the cabling capacitance shorts the current amplifier input (Starmark et al, 1999).…”

“…The bandwidth of the readout, B, is commonly defined as the corner frequency of the gain from gate charge to output voltage (Visscher et al, 1996). The performance requirements for the charge readout depend on the particular charge-counting scheme, but in general the bandwidth B places a limit on the fastest processes that can be detected and hence constrains the magnitude of the electric current that can be reliably monitored.…”

Preparation of Nanocrystalline Silicon Quantum Dots by Pulsed Plasma Processes with High Deposition Rates

“…For this purpose, the flow rate of SiH 4 is varied from 1 to 4 sccm. The plasma power is 3 W (0.42 W/cm 3 ) and the flow rate of Ar is 30 sccm. We assume that nc-Si is spherical with the height measured by AFM being the diameter.…”

“…The stainless steel plate with an orifice of 6mm diameter and 2mm length, separating the UHV chamber (10 -9 Torr) from the plasma cell, is used as the grounded electrode. The volume of the plasma cell is 230cm 3 . The deposition rate is monitored by a quartz crystal sensor during deposition.…”