Reconfigurable Multivalue Logic Functions of a Silicon Ellipsoidal Quantum-Dot Transistor Operating at Room Temperature

Abstract

Reconfigurable multivalue logic functions, which can perform the versatile arithmetic computation of weighted electronic data information, are demonstrated at room temperature on an all-around-gate silicon ellipsoidal quantum-dot transistor. The large single-hole transport energy of the silicon quantum ellipsoid allows the stable M-shaped Coulomb blockade oscillation characteristics at room temperature, and the all-around-gate structure of the fabricated transistor enables us to perform the precise self-control of the energetic Coulomb blockade conditions by changing the applied bias voltage. Such a self-controllability of the M-shaped Coulomb blockade oscillation characteristics provides a great advantage to choose multiple operation points for the reconfigurable multivalue logic functions. Consequently, the weighted data states (e.g., tri-value and quattro-value) are effectively demonstrated by utilizing only the device physics in the all-around-gate silicon ellipsoidal quantum-dot transistor. These findings are of great benefit for the practical application of the silicon quantum device at an elevated temperature for future nanoelectronic information technology.

Reduced Electron Temperature in Silicon Multi-Quantum-Dot Single-Electron Tunneling Devices

“…where G N+1 b is the multiplication of the tunnel barrier conductance, k B is the Boltzmann constant, and T eff is the effective electron temperature. For example, the I valley values for the single (N = 1), double (N = 2), and triple (N = 3) QD systems can be derived by Equations ( 3)-( 5), respectively [9,10]:…”

“…Thereafter, the surface of the suspended Si nanowire was oxidized by dry oxidation at 900 • C to form the gate oxide layer. During this step, the final diameter size of the Si nanowire was further shrunken down to <5 nm [7][8][9][10][11]. Through the sequential deposition of additional SiO 2 (≈30 nm) and n + poly-Si (≈250 nm) gate (G), finally, the formation of the GAA stacks was finalized.…”

“…In short, the electron can transfer one-by-one through the quantum states via the Coulomb blockade effect with its corresponding quantum-mechanical single-electron tunneling events. This leads to the unique transfer and output characteristics, such as Coulomb blockade oscillation (CBO) and negative differential conductance (NDC), respectively [6][7][8][9][10][11][12][13][14][15]. For example, the precise control of the single-electron (or even single-spin) transport characteristics was demonstrated on various types of semiconductor QD-based DTJ and MTJ device schemes (e.g., room temperature observation of multiple CBO peaks from multiple quantum states in a Si single-QD device [10], simultaneous observation of both sharp CBO and NDC peaks from a Si-QD DTJ device [9][10][11][12][13][14], bias voltage-controlled precise modulation of energetic Coulomb blockade conditions in a Si single-QD transistor [8], high-fidelity q-bit processing in Si MQD [16][17][18][19] and GaAs MQD [20][21][22] devices).…”

Looking Beyond 0 and 1: Principles and Technology of Multi‐Valued Logic Devices

“…It was enabled by utilizing Si ellipsoidal QD systems (EQD) with large spacings between quantum levels. [ 105 ] The Si EQD SET was self‐formed by using subsequent isotropic wet etching and thermal oxidation of the Si nanowire. The tunnel barriers were implemented as very thin areas (much less than 5 nm) adjacent to the central Si ellipsoid (Figure 8h).…”

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

“…[15][16][17][18] In particular, room-temperature operation of electron tunneling via a single donor has been realized via specially designed channels. [19][20][21][22] Due to the surface-transport mode, these miniaturized inversion-mode (IM) transistors show electrical characteristics strongly dependent on dopant atoms close to the gate dielectric. 23 The random distribution of dopants within the nanoscale channels would introduce significant fluctuations in the quantum properties of IM transistors, [24][25][26] which is detrimental to constructing quantum electronic systems.…”