tin barrier

**TiN Barrier** (Titanium Nitride) is a **conductive barrier/adhesion layer used in both FEOL and BEOL** — serving as a diffusion barrier for aluminum or tungsten metallization, a gate electrode component in HKMG stacks, and a hardmask material for BEOL patterning. **What Is TiN?** - **Properties**: $ ho approx 20-50$ $muOmega$·cm, $kappa_{thermal} approx 29$ W/m·K, extremely hard (Mohs ~9). - **Deposition**: PVD (sputtering), CVD (TiCl₄ + NH₃), or ALD (TDMAT + NH₃). - **Color**: Characteristic gold color (used decoratively in watchmaking and tools). **Why It Matters** - **HKMG**: TiN is a key work function metal in high-k/metal gate stacks ($Phi_m$ tuning for PMOS). - **Tungsten Contact**: TiN liner prevents WF₆ (tungsten precursor) from attacking the underlying silicon. - **Versatility**: One of the most versatile thin films in semiconductor manufacturing — barrier, electrode, hardmask, and etch stop. **TiN** is **the Swiss Army knife of thin films** — a durable, conductive material that plays multiple critical roles throughout the chip fabrication process.