tiva (thermally induced voltage alteration)

**TIVA** (Thermally Induced Voltage Alteration) is a **laser-based failure analysis technique** — that scans a modulated laser beam across the die while monitoring voltage changes at the device terminals, localizing resistive defects and open/short circuits. **How Does TIVA Work?** - **Setup**: Device biased at constant current. Laser scans the die surface (or backside through Si with 1340 nm laser). - **Principle**: Laser heating locally changes resistance. If the heated area is in the active current path, the terminal voltage changes. - **Open Defects**: Heating an open via causes it to expand/contract, momentarily changing contact resistance. - **Mapping**: The voltage change at each $(x, y)$ position creates an image highlighting the defect location. **Why It Matters** - **Open Detection**: TIVA excels at finding high-resistance opens (via voids, cracked metal) that other techniques miss. - **Backside Access**: Works through the silicon substrate (1340 nm is transparent to Si). - **Complementary**: TIVA finds "passive" defects while EMMI finds "active" emitting defects. **TIVA** is **laser diagnostics for interconnects** — using controlled heating to probe the health of every connection in the chip.