Optical beam induced current (OBIC) is a laser signal fault isolation technique used to isolate defects and damage in semiconductor materials. OBIC is effective in isolating failure mechanisms related to damaged semiconductor junctions and electrical shorts in gate oxides. Additionally, OBIC is instrumental in locating buried diffusions.
Main components of the OBIC system:
The bandgap of silicon is approximately 1.1 eV. Using an light source with a defined wavelength we may inject sufficient energy into the lattice to eject an electron from the valance band of the semiconductor. The following formula is used to calculate the level of energy injected into the silicon for a given wave length.
Silicon exhibits a bandgap voltage of approximately 1.12eV. By injecting a laser signal with a wavelength of 1080nm, equivalent to 1.148 eV, sufficient energy is applied to free valance band electrons resulting in an electrical current which may be sensed by the OBIC amplifier.
Main components of the OBIC system:
- Laser scanning microscope (LSM)
- Specimen current amplifier
- Device under test (DUT)
The bandgap of silicon is approximately 1.1 eV. Using an light source with a defined wavelength we may inject sufficient energy into the lattice to eject an electron from the valance band of the semiconductor. The following formula is used to calculate the level of energy injected into the silicon for a given wave length.
Silicon exhibits a bandgap voltage of approximately 1.12eV. By injecting a laser signal with a wavelength of 1080nm, equivalent to 1.148 eV, sufficient energy is applied to free valance band electrons resulting in an electrical current which may be sensed by the OBIC amplifier.