Abstract: A thyristor-based semiconductor device has a control port formed in a trench having a height-to-width aspect ratio that can be prohibitive to filling a bottom portion of the trench with an insulative material. According to an example embodiment of the present invention, a trench is formed in the substrate adjacent to a thyristor region, and a control port is formed near a bottom of the trench. An upper portion of the trench is then filled, thereby covering the control port. The control port is adapted to reduce the aspect ratio of a remaining portion of the trench over the control port, making it possible to fill trenches having a high height-to-width aspect ratio (e.g., at least 2:1). The thyristor control port is capacitively coupled to the thyristor region via a dielectric on a sidewall of the trench, and is configured and arranged to control current in the thyristor body via the capacitive coupling.

Abstract: A semiconductor memory device having a thyristor is manufactured in a manner that makes possible self-alignment of one or more portions of the thyristor. According to an example embodiment of the present invention, a gate is formed over a first portion of doped substrate. The gate is used to mask a portion of the doped substrate and a second portion of the substrate is doped before or after a spacer is formed. After the second portion of the substrate is doped, the spacer is then formed adjacent to the gate and used to mask the second portion of the substrate while a third portion of the substrate is doped. The gate and spacer are thus used to form self-aligned doped portions of the substrate, wherein the first and second portions form base regions and the third portion form an emitter region of a thyristor.

Abstract: A sensing circuit including a sense amplifier to resolve a data signal generated by a memory cell is disclosed herein. The sensing circuit includes a bit line to receive the data signal, a first pre-charge device coupled to the bit line and configured to pre-charge the bit line, a device for providing a bias coupled to the bit line and configured to provide a bias to the bit line, and a reference node configured to be at least one pre-determined level. In one embodiment the pre-determined level is equal to a low potential such as ground and in another embodiment equal to a high potential such as VDD. One or more switching devices allows for the activation or deactivation of the pre-charge device allowing to pre-charge the bit line to a certain potential and the sensing circuit quickly and accurately determines whether a logical state of ‘1’ or ‘0’ is being applied to the bit line.

Abstract: A reference cell produces a reference current that is about half of the current produced by a memory cell. The reference cell is essentially the same as the memory cell with an additional current reduction device that can be a transistor. Adjusting a reference voltage applied to the transistor allows the reference current to be varied. A control circuit to produce the reference voltage includes dedicated memory and reference cells and a feedback circuit that compares the two cell' currents. The feedback circuit applies the reference voltage to the reference cell of the control circuit and adjusts the reference voltage until the current from the reference cell is about half of th current from the memory cell. The reference voltage is then applied to other reference cells in a memory array.

Abstract: A delay line for an adjustable, high speed clock generator is based on two-stage multiplexing, in which for all pairs of adjacent taps, a change from a current tap to an adjacent tap in the pair is executed by switching only one of the first stage and second stage multiplexers. Control signals are generated for the first and second stage multiplexers by logic based on bidirectional shift registers. The delay line is suitable for generation of an output clock having an adjustable phase, allowing for smooth, glitch-free adjustment over a large range of phases.

Abstract: A semiconductor device having a thyristor-based memory device exhibits improved stability under adverse operating conditions related to temperature, noise, electrical disturbances and light. In one particular example embodiment of the present invention, a semiconductor device includes a thyristor-based memory device that uses a shunt that effects a leakage current in the thyristor. The thyristor includes a capacitively-coupled control port and anode and cathode end portions. Each of the end portions has an emitter region and an adjacent base region. In one implementation, the current shunt is located between the emitter and base region of one of the end portions of the thyristor and is configured and arranged to shunt low-level current therebetween.

Abstract: A thyristor-based semiconductor device exhibits a relatively increased base-emitter capacitance. According to an example embodiment of the present invention, the junction area between a base region and an adjacent emitter region of a thyristor is increased, relative to the junction area between other regions in the thyristor. In one implementation, the base region is formed extending on two sides of the emitter region. In another implementation, the thyristor is formed on a buried insulator layer of a silicon-on-insulator (SOI) structure, with the base region having a first portion laterally adjacent to the emitter region and having a second portion between the emitter region and the buried insulator.

Abstract: In a method of processing a semiconductor device, a silicide-blocking layer may be formed over a semiconductor material. After defining the silicide-blocking layer, impurities may be implanted into portions of the semiconductor material as defined by the silicide-blocking layer. After the implant, silicide may be formed in a surface region of the semiconductor material as permitted by the silicide-blocking layer. Regions of the impurity implant may comprise boundaries that are related to the outline of the silicide formed thereover. In a further embodiment, the implant may define a base region to a thyristor device. The implant may be performed with an angle of incidence to extend portions of the base region beneath a peripheral edge of the blocking mask. Next, an anode-emitter region may be formed using an implant of a substantially orthogonal angle of incidence and self-aligned to the mask.

Abstract: A dynamically-operating restoration circuit (106) is used to apply a voltage or current restore pulse signal to thyristor-based memory cells (108) and therein restore data in the cell using the internal positive feedback loop of the thyristor (110). In one example implementation, the internal positive feedback loop in the thyristor (110) is used to restore the conducting state of a device after the thyristor current drops below the holding current. A pulse and/or periodic waveform are defined and applied to ensure that the thyristor is not released from its conducting state. The time average of the periodic restore current in the thyristor may be lower than the holding current threshold. While not necessarily limited to memory cells that are thyristor-based, various embodiments of the invention have been found to be the particularly useful for high-speed, low-power memory cells in which a thin capacitively-coupled thyristor is used to provide a bi-stable storage element.

Abstract: Switching times of a thyristor-based semiconductor device are improved by enhancing carrier drainage from a buried thyristor-emitter region. According to an example embodiment of the present invention, a conductive contact extends to a doped well region buried in a substrate and is adapted to drain carriers therefrom. The device includes a thyristor body having at least one doped emitter region buried in the doped well region. A conductive thyristor control port is adapted to capacitively couple to the thyristor body and to control current flow therein. With this approach, the thyristor can be rapidly switched between resistance states, which has been found to be particularly useful in high-speed data latching implementations including but not limited to memory cell applications.

Abstract: A reference cell produces a voltage rise on a bit line that is proportional to, and preferably half of, the voltage rise on another bit line produced by a TCCT based memory cell in an “on” state. The reference cell includes an NDR device, a gate-like device disposed adjacent to the NDR device, a first resistive element coupled between the NDR device and the bit line, and a second resistive element coupled between a sink and the bit line. Resistances of the first and second resistive elements are about equal and about twice as much as the resistance of a pass transistor of the a TCCT based memory cell.

Abstract: A thyristor-based semiconductor device includes a thyristor body that has at least one region in the substrate and a thyristor control port in a trenched region of the device substrate. According to an example embodiment of the present invention, the trench is at least partially filled with a dielectric material and a control port adapted to capacitively couple to the at least one thyristor body region in the substrate. In a more specific implementation, the dielectric material includes deposited dielectric material that is adapted to exhibit resistance to voltage-induced stress that thermally-grown dielectric materials generally exhibit. In another implementation, the dielectric material includes thermally-grown dielectric material, and when used in connection with highly-doped material in the trench, grows faster on the highly-doped material than on a sidewall of the trench that faces the at least on thyristor body region in the substrate.

Abstract: A thyristor-based semiconductor device exhibits a relatively increased base-emitter capacitance. According to an example embodiment of the present invention, a base region and an adjacent emitter region of a thyristor are doped such that the emitter region has a lightly-doped portion having a light dopant concentration, relative to the base region. In one embodiment, the thyristor is implemented in a memory circuit, wherein the emitter region is coupled to a reference voltage line and a control port is arranged for capacitively coupling to the thyristor for controlling current flow therein. In another implementation, the thyristor is formed on a buried insulator layer of a silicon-on-insulator (SOI) structure. With these approaches, current flow in the thyristor, e.g., for data storage therein, can be tightly controlled.

Abstract: A semiconductor device includes doped regions of a substrate spaced at selected distances from features at an upper surface of the substrate. According to an example embodiment of the present invention, the doped regions are implanted and spaced apart from the features with the height of the features and the angle of an implant used for implanting the doped regions setting the space between the doped regions and the features. In one implementation, the height of the features is varied (e.g., with the features being defined using different steps, such as photolithography) to set the spacing of different doped regions. In another implementation, the angle of the implant is varied to set the spacing for different doped regions. In still another implementation, both the height of the features and angle of the implant are varied to set the spacing for different doped regions.

Abstract: A geometric DAC architecture includes a series of substantially identical sub-DACs, each sub-DAC having n taps. The sub-DACs are fed from a bias-DAC having m=(total number of taps needed)/n taps. The output of each of the m taps is increased geometrically at a rate of kn. The geometric DAC architecture control lines desirably require only (m+n) taps compared with (m×n) taps for the simpler more conventional approach. Further, the geometric DAC architecture requires less real estate than the simpler more conventional approach, is easy to expand because it is modular, and generates an output current that is always monotonic, regardless of errors in transistor sizes and PVT variations. The n tap control lines are coded by alternately inverting n control line inputs between sub-DACs such that any state transition associated with the geometric DAC occurs with only one bit change in each of the control lines.

Abstract: A semiconductor device includes a thyristor body having at least one region in a substrate. According to an example embodiment of the present invention, a trench is in a substrate and adjacent to a thyristor body region in the substrate. The trench is lined with an insulative material and further includes conductive material that is insulated from the thyristor body region in the substrate by the liner material. A conductive thyristor control port is located in the trench and adapted for capacitively coupling to the thyristor body region in the substrate and to control current in the thyristor body by causing an outflow of minority carriers in the thyristor. With this approach, conductive material can be used to fill a portion of the trench while using the trench portion including the conductive material to electrically isolate a portion of the thyristor body in the substrate.

Abstract: A semiconductor device is formed having a thyristor and trench arranged to electrically insulate an emitter region of the thyristor from another circuit structure. In one example embodiment of the present invention, a trench having a bottom portion with two different trench depths is etched in the substrate. A thyristor is formed having a control port in a trench and having an emitter region adjacent to the trench and below an upper surface of the substrate. A deeper portion of the trench electrically insulates the emitter region from the other circuit structure. The control port is capacitively coupled to the thyristor and to the other circuit structure (e.g. in response to at least one edge of a voltage pulse applied thereto). In one implementation, the trench further includes an emitter-access connector extending from the emitter region to an upper surface of the substrate.

Abstract: Minimal memory access times are realized by using a single access to a read-modify-write bank. A read-modify-write memory including at least one read-or-write bank is operated in a manner that uses at most one access to each of the at least one read-or-write banks for each read-modify-write access to the memory during a memory cycle. The access can be effected during a single clock cycle and can be used for read, write and read-modify-write memory access.

Abstract: A semiconductor device having a thyristor is manufactured and arranged in a manner that reduces or eliminates difficulties commonly experienced in the formation and implementation of such devices. According to an example embodiment of the present invention, a thyristor (e.g., a thin capacitively-coupled thyristor) is formed having some or all of the body of the thyristor formed inlayed in a semiconductor device substrate. A trench is provided in the substrate, and a semiconductor material is formed in the trench. One or more layers of material are formed in the trench and used to form a portion of a body of the thyristor. The thyristor is formed having adjacent regions of different polarity, wherein at least one of the adjacent regions includes a portion of the semiconductor material and at least one of the adjacent regions includes a portion of the substrate.

Abstract: The soft error rate in a semiconductor memory is improved via the use of a circuit and arrangement adapted to use a mirror bit to recover from a soft error. According to an example embodiment of the present invention, a semiconductor device includes first and mirror memory cells configured and arranged to receive and store a same bit in response to a write operation, with the memory cells more susceptible to a bit error in which the stored bit changes from a first state to a second state than to a change from the second state into the first state. The memory cells are separated by a distance that is sufficient to make the likelihood of both memory cells being upset by a same source very low. For a read operation, the bits stored at the fist and second memory cells are compared. If the bits are the same, the bit from the first and/or mirror bit is read out, and if the bits are different, a bit corresponding to the more susceptible state is read out. In this manner, soft errors can be overcome.