Abstract: An efficient method and computer program for modeling and improving stating memory performance across process variations and environmental conditions provides a mechanism for raising the performance of memory arrays beyond present levels/yields. Statistical (Monte-Carlo) analyses of subsets of circuit parameters are performed for each of several memory performance variables and then sensitivities of each performance variable to each of the circuit parameters are determined. The memory cell design parameters and/or operating conditions of the memory cells are then adjusted in conformity with the sensitivities, resulting in improved memory yield and/or performance. Once a performance level is attained, the sensitivities can then be used to alter the probability distributions of the performance variables to achieve a higher yield.

Abstract: Anti-reverse engineering techniques are provided. In one aspect, a method for forming at least one feature in an insulating layer is provided. The method comprises the following steps. Ions are selectively implanted in the insulating layer so as to form at least one implant region within the insulating layer, the implanted ions being configured to alter an etch rate through the insulating layer within the implant region. The insulating layer is etched to, at the same time, form at least one void both within the implant region and outside of the implant region, wherein the etch rate through the insulating layer within the implant region is different from an etch rate through the insulating layer outside of the implant region. The void is filled with at least one conductor material to form the feature in the insulating layer.

Abstract: A method and computer program product for controlling a storage device using per-element selectable power supply voltages provides energy conservation in storage devices while maintaining a particular performance level. The storage device is partitioned into multiple elements, which may be sub-arrays, rows, columns or individual storage cells. Each element has a corresponding virtual power supply rail that is provided with a selectable power supply voltage. The power supply voltage provided to the virtual power supply rail for an element is set to the minimum power supply voltage unless a higher power supply voltage is required for the element to meet performance requirements. A control cell may be provided within each element that provides a control signal that selects the power supply voltage supplied to the corresponding virtual power supply rail. The state of the cell may be set via a fuse or mask, or values may be loaded into the control cells at initialization of the storage device.

Abstract: Techniques for electronic circuit design simulation are provided. In one aspect, a method for electronic circuit design simulation includes the following steps. A model (e.g., a physics-based model) of the circuit design is created. Error tables are created containing data related to one or more regions of the circuit design. The model is modified with data from the error tables. The modified model is used to simulate the circuit design.

Abstract: A method and circuit for measuring internal pulses includes an enable circuit configured to receive a control signal from an on-chip built-in tester to enable measurement of internal circuits. A delay chain is configured to receive a pulse signal from an on-chip circuit component. Sampling latches each include a data input coupled between adjacent delay elements of the delay chain and synchronized with the clock signal such that a transition in the pulse signal is indicated by comparing adjacent digital values in an output sequence.

Abstract: An Integrated Circuit (IC) chip that may be a bulk CMOS IC chip with silicon on insulator (SOI) Field Effect Transistors (FETs) and method of making the chip. The IC chip includes areas with pockets of buried insulator strata and FETs formed on the strata are SOI FETs. The SOI FETs may include Partially Depleted SOI (PD-SOI) FETs and Fully Depleted SOI (FD-SOI) FETs and the chip may include bulk FETs as well. The FETs are formed by contouring the surface of a wafer, conformally implanting oxygen to a uniform depth, and planarizing to remove the Buried OXide (BOX) in bulk FET regions.

Abstract: A method and circuit for measuring internal pulses includes an enable circuit configured to receive a control signal from an on-chip built-in tester to enable measurement of internal circuits. A delay chain is configured to receive a pulse signal from an on-chip circuit component. Sampling latches each include a data input coupled between adjacent delay elements of the delay chain and synchronized with the clock signal such that a transition in the pulse signal is indicated by comparing adjacent digital values in an output sequence.

Abstract: Techniques are provided for fuse/anti-fuse structures, including an inner conductor structure, an insulating layer spaced outwardly of the inner conductor structure, an outer conductor structure disposed outwardly of the insulating layer, and a cavity-defining structure that defines a cavity, with at least a portion of the cavity-defining structure being formed from at least one of the inner conductor structure, the insulating layer, and the outer conductor structure. Methods of making and programming the fuse/anti-fuse structures are also provided.

Abstract: Mechanisms are provided for modeling a plurality of devices of an integrated circuit design as a single statistically equivalent wide device. An integrated circuit design is analyzed to identify a portion of the integrated circuit design having the plurality of devices. For the plurality of devices, a statistical model of a single statistically equivalent wide device is generated which has a statistical distribution of at least one operating characteristic of the single statistically equivalent wide device that captures statistical operating characteristic distributions of individual devices in the plurality of devices. At least one statistical operating characteristic of the single statistically equivalent wide device is a complex non-linear function of the statistical operating characteristics of the individual devices. The integrated circuit design is modeled using the single statistically equivalent wide device.

Abstract: The present invention provides an improved SRAM cell. Specifically, the present invention provides an SRAM cell having one or more sets of stacked transistors for isolating the cell during a read operation. Depending on the embodiment, the SRAM cell of the present invention can have eight or ten transistors. Regardless, the SRAM cell of the present invention typically includes separate/decoupled write word and read word lines, a pair of cross-coupled inverters, and a complimentary pair of pass transistors that are coupled to the write word line. Each set of stacked transistors implemented within the SRAM cell has a transistor that is coupled to a bit line as well as the read word line.

Abstract: Methods and apparatus are provided for read/write control and bit selection with false read suppression in an SRAM. According to one aspect of the invention, a bit select circuit is provided for an SRAM. The disclosed bit select circuit comprises one or more transistors controlled by a write control gate signal to prevent data from being read from one or more data cells during a write operation. The transistors can comprise, for example, a pair of gated transistors controlled by the write control gate signal. The write control gate signal prevents data from being read from one or more data cells while the write control gate signal is in a predefined state.

Abstract: A memory cell for interconnection with READ and WRITE word lines and READ and WRITE bit lines includes a logical storage element such as a flip-flop formed by a first inverter and a second inverter cross-coupled to the first inverter. The storage element has first and second terminals and a storage element supply voltage terminal configured for interconnection with a first supply voltage. A WRITE access device is configured to selectively interconnect the first terminal to the WRITE bit line under control of the WRITE word line, and a pair of series READ access devices are configured to ground the READ bit line when the READ word line is active and the second terminal is at a high logical level. A logical “one” can be written to the storage element when a second supply voltage, greater than the first supply voltage, is applied to the WRITE word line, substantially without the use of a complementary WRITE bit line.

Abstract: A method for circuit simulation using a netlist in which a first device having an unmodeled, nonlinear behavior is modified by inserting a second device which has a nonlinear response approximating the unmodeled nonlinear behavior. The first device may be for example a first transistor and the second device may be a variable current source, in particular one whose current is modeled after a floating transistor template which represents gate leakage current of the first transistor (gate-to-source or gate-to-drain). During simulation of the circuit a parameter such as a gate-to-source voltage of the second transistor is controlled to model gate leakage. The model parameters can be a function of an effective quantum mechanical oxide thickness value of a gate of the first transistor technology.

Abstract: A test circuit and programmable voltage divider that may be used in the test circuit. The programmable voltage divider develops a voltage difference signal that may be digitally selected. The test circuit may be used to test and characterize sense amplifiers. The programmable voltage divider develops a signal with a selected polarity and magnitude that is provided to a sense amplifier being tested. The sense amplifier is set and its output latched. The latch contents are checked against an expected value. The difference voltage may be changed and the path retested to find passing and failing points.

Abstract: A local on-chip programmable pulsewidth and delay generating circuit includes a clock generation circuit configured to receive a global clock signal and output a local clock signal. The clock generation circuit includes a pulse shaping portion which adjusts a pulse width of the global clock signal in accordance with at least one of a trailing edge delay and a leading edge delay. The leading edge delay is generated by a leading edge delay circuit, and the trailing edge delay is generated by a trailing edge delay circuit configured to apply a delay to a trailing edge of a pulse. The trailing edge delay circuit includes a delay chain having programmable stages of delay elements, each stage being independently controlled using control bits decoded from address latches.

Abstract: A failure probability for a system having multi-fail regions is computed by generating failure directions in a space whose dimensions are the system parameters under consideration. The failure directions are preferably uniform, forming radial slices. The failure directions may be weighted. The radial slices have fail boundaries defining fail regions comparable to broken shells. The distribution of the system parameters is integrated across the broken shell regions to derive a failure contribution for each failure direction. The failure probability is the sum of products of each failure contribution and its weight. Failure contributions are computed using equivalent expressions dependent on the number of dimensions, which can be used to build lookup tables for normalized fail boundary radii. The entire process can be iteratively repeated with successively increasing failure directions until the failure probability converges.

Abstract: A method and computer program for selecting circuit repairs using redundant elements with consideration of aging effects provides a mechanism for raising short-term and long-term performance of memory arrays beyond present levels/yields. Available redundant elements are used as replacements for selected elements in the array. The elements for replacement are selected by BOL (beginning-of-life) testing at a selected operating point that maximizes the end-of-life (EOL) yield distribution as among a set of operating points at which post-repair yield requirements are met at beginning-of-life (BOL). The selected operating point is therefore the “best” operating point to improve yield at EOL for a desired range of operating points or maximize the EOL operating range. For a given BOL repair operating point, the yield at EOL is computed. The operating point having the best yield at EOL is selected and testing is performed at that operating point to select repairs.

Abstract: Correlated failure distribution for memory arrays having different groupings of memory cells is estimated by constructing memory unit models for the groupings based on multiple parameters, establishing failure conditions of the memory unit model using fast statistical analysis, calculating a fail boundary of the parameters for each memory unit model based on its corresponding failure conditions, and constructing memory array models characterized by the fail boundaries. Operation of a memory array model is repeatedly simulated with random values of the parameters assigned to the memory cells and peripheral logic elements to identify memory unit failures for each simulated operation. A mean and a variance is calculated for each memory array model, and an optimal architecture can thereafter be identified by selecting the grouping exhibiting the best mean and variance, subject to any other circuit requirements such as power or area.

Abstract: A leakage current monitor circuit provides an accurate statistically representative analog of true off-state leakage current in a digital circuit integrated on a die. At least one N-type transistor and at least one P-type transistor separate from the digital circuit are sized to represent the total area of the corresponding type transistors in the digital circuit. The gates of the N-type transistor and P-type transistors are set to voltages according to the corresponding off-state logic levels of the digital circuit. The N-type and P-type transistors form a portion of corresponding current mirror circuits, which can provide outputs to a leakage current monitor and/or a control circuit such as a comparator that determines when leakage current for the N-type or P-type devices has exceeded a threshold. The output of the measurement/control circuit can be used to determine a temperature of and/or control operation of the digital circuit or the system environment of the integrated circuit.

Abstract: A semiconductor device includes a semiconductor material having two crystal orientations. The semiconductor material forms an active area of the device. A device channel is formed on the two crystal orientations, which include a first region formed in a first crystal orientation surface of the semiconductor material, and a second region formed in a second crystal orientation surface of the semiconductor material wherein the first crystal orientation surface forms an angle with the second crystal orientation surface and the device channel covers at least an intersection of the angle.