Systems and methods for precise signal injection into microelectronic devices

An optical carrier injection device comprising:

• a laser driven by a radio frequency (RF) signal configured to apply a pulsed optical beam having pulse duration of 900 femtoseconds or lower on a backside of a substrate of an integrated circuit (IC) wafer or chip;
• an optical train arranged to focus the pulsed optical beam at a focal point in an active layer disposed on a frontside of the substrate;
• and
• a readout device configured to measure an output signal comprising an electrical signal produced by the IC wafer or chip in response to the carriers injected at the focal point in the active layer or a light output signal produced by recombination of the carriers injected at the focal point or nonlinear interactions in the active layer;
• wherein the readout device uses lock-in amplification and includes a lock-in amplifier that is locked to a reference signal comprising boxcar averaging triggered from laser pulses of the pulsed optical beam;
• wherein a photon energy of the pulsed optical beam is lower than a bandgap of the substrate;
• and
• wherein photons of the optical beam are absorbed at the focal point in the active layer by nonlinear optical interaction to inject carriers at the focal point in the active layer.

An optical carrier injection device comprising:

• a translation stage configured to hold an integrated circuit (IC) wafer or chip;
• a laser configured to be driven by a radio frequency (RF) signal to output a pulsed optical beam having pulse duration of 900 femtoseconds or lower;
• an optical train arranged to apply the pulsed optical beam on a backside of a substrate of the IC wafer or chip whereby the pulsed optical beam passes through the substrate to reach an active layer that is disposed on a frontside of the substrate, the optical chain including an objective arranged to focus the pulsed optical beam at a focal point in the active layer disposed on the frontside of the substrate;
• and
• a readout device comprising a lock-in amplifier and one or more of a voltmeter, an ammeter, an ohmmeter, and/or an optical detector, the readout device configured to measure an output signal generated by carriers injected into the active layer at the focal point in the active layer by the pulsed optical beam undergoing absorption by nonlinear optical interaction at the focal point in the active layer;
• wherein the lock-in amplifier is locked to a generated signal at the repetition rate of and phase-locked to the pulsed output of the laser.