Laser assisted device alteration using two-photon absorption
AssigneeDCG Systems, Inc.
InventorsPraveen VEDAGARBHA, Derryck Reid
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Abstract
A Two-Photon Laser Assisted Device Alteration technique is presented. Fault localization is investigated by exploiting the non-linear two-photon absorption mechanism to induce LADA effects. Femtosecond laser pulses of wavelength having photon energy lower than the silicon bandgap are directed at the area of interest, while the DUT is stimulated with test vectors. The laser pulses are synchronized to the DUT stimulation, so that switching timing can be altered using the two-photon absorption effect.
Claims13
A system for performing fault localization in device under test (DUT), wherein the DUT is stimulated by a tester, comprising:
- a laser source providing laser beam pulses of femtosecond pulsewidth and wavelength above silicon bandgap;
- optical elements receiving the laser beam pulses and directing the laser beam pulses onto an area of interest in the DUT;
- timing electronics receiving a sync signal from the tester and controlling the timing of the laser source according to the sync signal;
- wherein the pulsewidth and wavelength of the laser beam pulses are selected so as to cause two-photon absorption in the DUT.
A method for altering the switching time of a device under test, the device being stimulated by test vectors from a tester, comprising:
- generating laser beam pulses of femtosecond pulsewidth and wavelength above silicon bandgap;
- directing the laser beam pulses onto an area of interest in the DUT;
- controlling the timing of the laser source according to sync signal from the tester;
- wherein the pulsewidth and wavelength of the laser beam pulses are selected so as to cause two-photon absorption in the DUT.
A method for testing a device under test (DUT), the DUT being stimulated by a tester, comprising:
- applying a first set of test vectors from the tester to the DUT to determine the marginal settings of the DUT;
- setting voltage and frequency of a second set of test vectors of the tester according to the marginal settings of the DUT;
- repeatedly applying the second set of test vectors from the tester to the DUT;
- obtaining a sync signal from the tester;
- applying the sync signal to a laser source to obtain laser pulses of femtosecond pulse width and wavelength higher than silicon band gap;
- applying the laser pulses to an area of interest in the DUT to thereby increase or decrease the DUT switching time;
- monitoring the DUT output to determine location of failure.
Dependencies are inferred from the claim text.