Dcg Systems Gmbh

Fei Efa, Inc.

Antoine Reverdy

Herve Deslandes

Prasad Sabbineni

Ingrid De Wolf

Rudolf Schlangen

Thierry Parrassin

An apparatus and method for optical probing of a DUT is disclosed. The system enables identifying, localizing and classifying faulty devices within the DUT. A selected area of the DUT is imaged while the DUT is receiving test signals, which may be static or dynamic, i.e., causing certain of the active devices to modulate. Light from the DUT is collected and is passed through a transparent diffracting grating prior to imaging it by a sensor and converting it into an electrical signal. The resulting image includes the zero order and first order diffraction of the grating. The grating is configured such that the zero order is in registration with emission sites imaged when the grating is outside the optical path.

Spectral mapping of photo emission

Controlled amount of heat is injected into a stacked die using a light beam, and the propagated heat is measuring with LIT camera from the other side of the die. The thermal image obtained can be characterized so that it can be used to calibrate the phase shift from a given stack layer, or can be used to identify defects in the stacked die. The process can be repeated for each die in the stack to generate a reference for future testing. The thermal image can be investigated to detect faults, such as voids in vias, e.g., TSV.

Lock in thermal laser stimulation through one side of the device while acquiring lock-in thermal emission images on the opposite side

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Grenoble, France

Antoine Reverdy