DCG Systems - Technology

Technology

Static Laser Stimulation

The aim of Static Laser Stimulation (SLS) is to localize current related defects such as shorts. It consists of scanning a continuous laser beam on the front or backside of the device under test (DUT). The laser stimulation effects on the device behavior are observed through a device power consumption change. Static Laser Stimulation is advantageously applied to detect defects in devices presenting an abnormal supply current (IDD) or supply current in the quiescent state (IDDQ).

Two types of laser stimulation can be employed:

SLS Thermal Laser Stimulation (TLS) Techniques

TLS uses the 1340nm laser beam to induce heating. Thermal heating will affect the DUT current consumption through 1) a resistance variation, 2) a thermoelectric energy conversion or Seebeck effect. TLS is best suited for localizing current related defects in the interconnect layers such as metallic or polysilicon shorts.

Optical Beam Induced Resistance Change (OBIRCH)

Thermally Induced Voltage Alteration (TIVA)

Seebeck Effect Imaging (SEI)

SLS Photoelectric Laser Stimulation (PLS) Techniques

PLS uses the 1064nm laser beam to induce photo-current into the circuit. Photo-currents are generated at silicon junction upon the dissociation of the photo generated free carriers. The photo-currents will directly impact the DUT current consumption.

PLS is best suited for localizing defects within p-n junctions such as melted silicon filaments. It can also be used to localize non-current related defects such as opens by comparing PLS images from a failed device with PLS images from a reference device.

Optical Beam Induced Current (OBIC)

Light Induced Voltage Alteration (LIVA)

Non-biased Optical Beam Induced Current (NB-OBIC)