Radial addressing of nanowires

Abstract

We introduce radial encoding of nanowires (NWs), a new method of differentiating and controlling NWs by a small set of mesoscale wires for use in crossbar memories. We describe methods of controlling these NWs and give efficient manufacturing algorithms. These new encoding and decoding methods do not suffer from the misalignment characteristic of flow-aligned NWs. They achieve comparable effective pitch and resulting memory density with axially encoded NWs while avoiding potential cases of address ambiguity and simplifying NW preparation. We also explore hybrid axial/radial encodings and show that they offer no net benefit over pure codes.

Hybrid resistor/FET-logic demultiplexer architecture design for hybrid CMOS/nanodevice circuits

“…This hybrid resistor/FET-logic demux has the same function as the pure FET-based demux solutions proposed in [13][14][15]. Due to the regularity of the pFETs array, it is reasonable to expect that the fabrication of pFET can be relatively easy.…”

“…Several possible solutions have been proposed to tackle this challenge, which may be categorized based on whether the microwire-to-nanowire accessibility is realized through direct mircowire-nanowire ohmic contact [9,11] or a logic circuit called microwire-to-nanowire demultiplexer (demux) [12][13][14][15][16]. All the proposed demux design solutions have a crossbar structure consisting of one layer of parallel nanowires and one layer of parallel microwires.…”

“…In prior work on demux design, the demultiplexing function is realized by implementing a single type of devices such as resistor [16], diode [12], or field effect transistor (FET) [13][14][15] at a subset of the microwire-nanowire crosspoints. Because the nonlinear nature of diode's and FET's electrical characteristics can well match the nonlinear nature of the desired demultiplexing function, diode-logic and FET-logic demuxes can, in principle, very well approximate the ideal demultiplexing behavior.…”

Fault-tolerant multi-level logic decoder for nanoscale crossbar memory arrays

“…They are addressable when they have different VT patterns; this event has a certain probability that may be increased by increasing the number of addressing wires. On the other hand, the radial decoder [28] relies on NWs with several radial doping shells. After a series of etching of the NW shells, the remaining one in each region depends on the etching order.…”

Analysis of a Mask-Based Nanowire Decoder

“…Their analysis indicates that these two strategies require less area than the strategy that requires all NWs within each contact group be addressable [18]. A new technique for encoding of NWs through the use of shells of different types has also been proposed and shown to be competitive with modulation doping [25].…”