organosilicate glass (osg)

**Organosilicate Glass (OSG)** is the **generic material science term for carbon-doped oxide (SiCOH) dielectrics** — an amorphous glass-like material where organic methyl groups (-CH₃) replace some of the bridging oxygen atoms in the SiO₂ network, reducing density and dielectric constant. **What Is OSG?** - **Structure**: Si-O-Si backbone with pendant -CH₃ groups. - **Properties**: $kappa approx 2.7-3.0$ (dense), $kappa approx 2.0-2.5$ (porous). - **Synonyms**: SiCOH, CDO (Carbon-Doped Oxide), Black Diamond™ (Applied Materials), Coral™ (Novellus/Lam). - **Deposition**: PECVD with organosilicon precursors. **Why It Matters** - **Standard IMD**: The universal inter-metal dielectric for 90nm through 3nm nodes. - **Tunable**: By varying carbon content and porosity, $kappa$ can be tuned over a wide range. - **Research Focus**: Improving mechanical strength and moisture resistance remains an active area. **OSG** is **the generic chemistry behind every commercial low-k dielectric** — the silicon-oxygen-carbon glass that insulates modern chip interconnects.