Abstract: A structure and method of testing degradation of semiconductor devices by stressing an array of several semiconductor devices at the same time and measuring the resulting degradation separately for each individual device to obtain an estimate of its expected lifetime is provided. The devices may be subjected to stress that is either in a pulsed state or in a DC state. An on-chip pulse generator may be used for stressing in the pulsed state.

Abstract: A structure is provided for sensing an analyte in an environment. The structure may include a ring oscillator on a semiconductor substrate, the ring oscillator includes an AND gate, an odd number of inverters, and a carbon device connected in series, the carbon device is exposed to an environment such that a frequency of the ring oscillator changes when the carbon device is exposed to the analyte in the environment.

Abstract: A method of measuring semiconductor output characteristics is provided that includes connecting a pulse generator to the gate structure of a semiconductor device, and applying a plurality of voltage pulses at least some of which having a different pulse width to the gate structure of the semiconductor device. The average current is measured from the drain structure of the device for a duration of each pulse of the plurality of pulses. From the measured values for the average current, a self-heating curve of the average current divided by the pulse width is plotted as a function of the pulse width. The self-heating curve is then extrapolated to a pulse width substantially equal to zero to provide a value of drain current measurements without self-heating effects.

Abstract: A computer system may determine a first set of output values for a set of test paths at a first time. Each output value may correspond to a test path in the set of test paths. The computer system may then determine a second set of output values at a second time. Each output value in the second set of output values may have an associated output value in the first set of output values. The computer system may then determine whether degradation of the semiconductor chip has occurred by comparing the first set of output values to the second set of output values.

Abstract: Techniques for use of carbon nanotubes as an anti-tampering feature and for use of randomly metallic or semiconducting carbon nanotubes in the generation of a physically unclonable cryptographic key generation are provided. In one aspect, a cryptographic key having an anti-tampering feature is provided which includes: an array of memory bits oriented along at least one bit line and at least one word line, wherein each of the memory bits comprises a memory cell, wherein the cryptographic key is stored in the memory cell, and wherein the memory cell is connected to the at least one bit line; and a metallic carbon nanotube interconnect which connects the memory cell to the at least one word line. A cryptographic key and method for processing the cryptographic key are also provided.

Abstract: Methods and systems for measuring a duty cycle of a signal include applying a first branch of an input signal directly to a latch. A delay of a second branch of the input signal is incrementally increased, with the second branch being applied to the latch, until the latch changes its output. A delay, corresponding to the latch's changed output, is divided by a period of the input signal to determine a duty cycle of the input signal.

Abstract: Techniques for use of carbon nanotubes as an anti-tampering feature and for use of randomly metallic or semiconducting carbon nanotubes in the generation of a physically unclonable cryptographic key generation are provided. In one aspect, a cryptographic key having an anti-tampering feature is provided which includes: an array of memory bits oriented along at least one bit line and at least one word line, wherein each of the memory bits comprises a memory cell, wherein the cryptographic key is stored in the memory cell, and wherein the memory cell is connected to the at least one bit line; and a metallic carbon nanotube interconnect which connects the memory cell to the at least one word line. A cryptographic key and method for processing the cryptographic key are also provided.

Abstract: Methods and systems for measuring degradation includes measuring an initial electrical characteristic of a test device in a ring oscillator that includes multiple oscillator stages, each having a delay stage and one or more fan-out devices, and a test stage having a delay stage and the test device. The ring oscillator is operated for a period of time. The electrical characteristic of the test device is measured after operating the ring oscillator. A level of degradation in the test device is determined using a processor based on the measurements of the electrical characteristic of the test device.

Abstract: Methods and circuits for monitoring circuit degradation include measuring degradation in a plurality of on-chip test oscillators that vary according to a quantity that influences hot carrier injection (HCI) degradation. The measured degradation for the plurality of test oscillators is extrapolated to determine a bias temperature instability (BTI) contribution to the measured degradation. The BTI contribution is subtracted from the measured degradation at a predetermined value of the quantity to determine the HCI degradation for devices represented by the predetermined value.

Abstract: A structure is provided for sensing an analyte in an environment. The structure may include a ring oscillator on a semiconductor substrate, the ring oscillator includes an AND gate, an odd number of inverters, and a carbon device connected in series, the carbon device is exposed to an environment such that a frequency of the ring oscillator changes when the carbon device is exposed to the analyte in the environment.

Abstract: A structure and method of testing degradation of semiconductor devices by stressing an array of several semiconductor devices at the same time and measuring the resulting degradation separately for each individual device to obtain an estimate of its expected lifetime is provided. The devices may be subjected to stress that is either in a pulsed state or in a DC state. An on-chip pulse generator may be used for stressing in the pulsed state.

Abstract: A test structure and method to detect open circuits due to electromigration or burn-out in test wires and inter-level vias. Electromigration occurs when current flows through circuit wires leading to a circuit interruption within the wire. The test structure is a passive test wire arranged in one of several configurations within the circuit of a computer chip. The dimensions and resistances of test wires can vary according to the test structure configuration. Each test wire is measured for an electrical discontinuity after the computer chip is powered-on. If a wiring interruption is detected, it is concluded that the chip had been powered-on before.

Abstract: A method of assembling a remote sensor system to detect a gas or chemical and a remote sensor system are described. The method includes fabricating a sensor, the sensor outputting a sensor signal that changes upon contact of the sensor with the gas or chemical and the sensor having an input port for a clock signal, coupling a capacitor to the sensor, the capacitor output voltage resulting from the sensor signal output by the sensor, and coupling a mixer to the capacitor and a low frequency oscillator, the mixer configured to mix the capacitor output voltage with the low frequency oscillator output to generate an output signal. The method also includes coupling an antenna to the mixer, the antenna configured to transmit the output signal indicating detection of the gas or chemical.

Abstract: A method of assembling a remote sensor system to detect a gas or chemical and a remote sensor system are described. The method includes fabricating a sensor, the sensor outputting a sensor signal that changes upon contact of the sensor with the gas or chemical and the sensor having an input port for a clock signal, coupling a capacitor to the sensor, the capacitor output voltage resulting from the sensor signal output by the sensor, and coupling a mixer to the capacitor and a low frequency oscillator, the mixer configured to mix the capacitor output voltage with the low frequency oscillator output to generate an output signal. The method also includes coupling an antenna to the mixer, the antenna configured to transmit the output signal indicating detection of the gas or chemical.

Abstract: A method of measuring semiconductor output characteristics is provided that includes connecting a pulse generator to the gate structure of a semiconductor device, and applying a plurality of voltage pulses at least some of which having a different pulse width to the gate structure of the semiconductor device. The average current is measured from the drain structure of the device for a duration of each pulse of the plurality of pulses. From the measured values for the average current, a self-heating curve of the average current divided by the pulse width is plotted as a function of the pulse width. The self-heating curve is then extrapolated to a pulse width substantially equal to zero to provide a value of drain current measurements without self-heating effects.

Abstract: A method of measuring semiconductor output characteristics is provided that includes connecting a pulse generator to the gate structure of a semiconductor device, and applying a plurality of voltage pulses at least some of which having a different pulse width to the gate structure of the semiconductor device. The average current is measured from the drain structure of the device for a duration of each pulse of the plurality of pulses. From the measured values for the average current, a self-heating curve of the average current divided by the pulse width is plotted as a function of the pulse width. The self-heating curve is then extrapolated to a pulse width substantially equal to zero to provide a value of drain current measurements without self-heating effects.

Abstract: An integrated circuit includes a test block which in turn includes a plurality of identical paths; a counter selectively coupled to the plurality of identical paths to selectively obtain a count of at least one of correctly operating paths and incorrectly operating paths from each of the plurality of identical paths; and a plurality of count latches selectively coupled to the counter to store output of the counter. Each path in turn includes a first clocked latch; a clocked logic path beginning and ending at the first clocked latch; and a clocked detection circuit coupled to the first clocked latch and the counter, which determines whether the clocked logic path is operating properly in a given clock period.

Abstract: Techniques for use of carbon nanotubes as an anti-tampering feature and for use of randomly metallic or semiconducting carbon nanotubes in the generation of a physically unclonable cryptographic key generation are provided. In one aspect, a cryptographic key having an anti-tampering feature is provided which includes: an array of memory bits oriented along at least one bit line and at least one word line, wherein each of the memory bits comprises a memory cell, wherein the cryptographic key is stored in the memory cell, and wherein the memory cell is connected to the at least one bit line; and a metallic carbon nanotube interconnect which connects the memory cell to the at least one word line. A cryptographic key and method for processing the cryptographic key are also provided.

Abstract: An oscillator circuit includes a field effect transistor and a resonant circuit having a first terminal connected to the field effect transistor. The resonant circuit includes an inductance and a capacitance and has a second terminal for connecting to a radiator. The field effect transistor includes a gate electrode coupled to a source of gate voltage, a source electrode, a drain electrode and a graphene channel disposed between the source electrode and the drain electrode and electrically connected thereto. The graphene channel is disposed relative to the gate electrode for being biased by the gate electrode into a negative differential resistance region of operation. The oscillator circuit is capable of generating a continuous wave THz frequency signal, and is further capable of being enabled and disabled by the bias applied to the gate electrode.

Abstract: A test structure and method to detect open circuits due to electromigration or burn-out in test wires and inter-level vias. Electromigration occurs when current flows through circuit wires leading to a circuit interruption within the wire. The test structure is a passive test wire arranged in one of several configurations within the circuit of a computer chip. The dimensions and resistances of test wires can vary according to the test structure configuration. Each test wire is measured for an electrical discontinuity after the computer chip is powered-on. If a wiring interruption is detected, it is concluded that the chip had been powered-on before.