Static Laser Stimulation (SLS)
- Static Laser Stimulation (SLS)
- 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)
