Abstract:
One embodiment of the present invention is a method for constructing defect-and-failure-tolerant demultiplexers. This method is applicable to nanoscale, microscale, or larger-scale demultiplexer circuits. Demultiplexer circuits can be viewed as a set of AND gates, each including a reversibly switchable interconnection between a number of address lines, or address-line-derived signal lines, and an output signal line. Each reversibly switchable interconnection includes one or more reversibly switchable elements. In certain demultiplexer embodiments, NMOS and/or PMOS transistors are employed as reversibly switchable elements. In the method that represents one embodiment of the present invention, two or more serially connected transistors are employed in each reversibly switchable interconnection, so that short defects in up to one less than the number of serially interconnected transistors does not lead to failure of the reversibly switchable interconnection. In addition, error-control-encoding techniques are used to introduce additional address-line-derived signal lines and additional switchable interconnections so that the demultiplexer may function even when a number of individual, switchable interconnections are open-defective.
Abstract:
Embodiments of the present invention include defect-tolerant demultiplexer crossbars that employ, or that can be modeled by demultiplexer crossbars that employ, threshold logic “TL” elements. The threshold-logic elements provide for tolerance for signal variation on internal signals lines of a defect-tolerant demultiplexer crossbar, and thus tolerance for defects which produce internal signal variation.
Abstract:
Certain embodiments of the present invention are directed to a method of programming nanowire-to-conductive element electrical connections. The method comprises: providing a substrate including a number of conductive elements overlaid with a first layer of nanowires, at least some of the conductive elements electrically coupled to more than one of the nanowires through individual switching junctions, each of the switching junctions configured in either a low-conductance state or a high-conductance state; and switching a portion of the switching junctions from the low-conductance state to the high-conductance state or the high-conductance state to the low-conductance state so that individual nanowires of the first layer of nanowires are electrically coupled to different conductive elements of the number of conductive elements using a different one of the switching junctions configured in the high-conductance state. Other embodiments of the present invention are directed to a nanowire structure including a mixed-scale interface.
Abstract:
Lithography tools and substrates are aligned by generating geometric interference patterns using optical gratings associated with the lithography tools and substrates. In some embodiments, the relative position between a substrate and lithography tool is adjusted to cause at least one geometric shape to have a predetermined size or shape representing acceptable alignment. In additional embodiments, Moiré patterns that exhibit varying sensitivity are used to align substrates and lithography tools. Furthermore, lithography tools and substrates are aligned by causing radiation to interact with optical gratings positioned between the lithography tools and substrates. Lithography tools include an optical grating configured to generate a portion of an interference pattern that exhibits a sensitivity that increases as the relative position between the tools and a substrate moves towards a predetermined alignment position.
Abstract:
Certain embodiments of the present invention are directed to a method of fabricating a mixed-scale electronic interface. A substrate is provided with a first set of conductive elements. A first layer of nanowires may be formed over the first set of conductive elements. A number of channels may be formed, with each of the channels extending diagonally through a number of the nanowires of the first layer. A number of pads may be formed, each of which is electrically interconnected with an underlying conductive element of the first set of conductive elements and one or more adjacent nanowires of the first layer of nanowires. The pads and corresponding electrically interconnected nanowires define a number of pad-interconnected-nanowire-units. Additional embodiments are directed to a method of forming a nanoimprinting mold and a method of selectively programming nanowire-to-conductive element electrical connections.
Abstract:
Various embodiments of the present invention are directed to crossbar-memory systems to methods for writing information to and reading information stored in such systems. In one embodiment of the present invention, a crossbar-memory system comprises a first layer of microscale signal lines, a second layer of microscale signal lines, a first layer of nanowires configured so that each first layer nanowire overlaps each first layer microscale signal line, and a second layer of nanowires configured so that each second layer nanowire overlaps each second layer microscale signal line and overlaps each first layer nanowire. The crossbar-memory system includes nonlinear-tunneling resistors configured to selectively connect first layer nanowires to first layer microscale signal lines and to selectively connect second layer nanowires to second layer microscale signal lines. The crossbar-memory system also includes nonlinear tunneling-hysteretic resistors configured to connect each first layer nanowire to each second layer nanowire at each crossbar intersection.
Abstract:
One embodiment of the present invention provides a demultiplexer implemented as a nanowire crossbar or a hybrid nanowire/microscale-signal-line crossbar with resistor-like nanowire junctions. The demultiplexer of one embodiment provides demultiplexing of signals input on k microscale address lines to 2k or fewer nanowires, employing supplemental, internal address lines to map 2k nanowire addresses to a larger, internal, n-bit address space, where n>k. A second demultiplexer embodiment of the present invention provides demultiplexing of signals input on n microscale address lines to 2k nanowires, with n>k, using 2k, well-distributed, n-bit external addresses to access the 2k nanowires. Additional embodiments of the present invention include a method for evaluating different mappings of nanowire addresses to internal address-spaces of different sizes, or to evaluate mappings of nanowires to external address-spaces of different sizes, metrics for evaluating address mapping and demultiplexer designs, and demultiplexer design methods.