| 摘要 |
<p>A permanent protective hardmask 40 protects the dielectric properties of a main bulk dielectric layer 30 having a desirably low dielectric constant in a semiconductor device from undesirable increases in the dielectric constant, undesirable increases in current leakage, and low device yield from surface scratching during subsequent processing steps. The protective hardmask 40 further includes a single layer 50 or dual layer 50,60 sacrificial hardmask particularly useful when interconnect structures such as via openings and/or lines are formed in the low dielectric material during the course of making the final product. The sacrificial hardmask layers 50,60 and the permanent hardmask layer 40 may be formed in a single step from a same precursor wherein process conditions are altered to provide films of differing dielectric constants. Most preferably, a dual damascene structure has a tri-layer hardmask comprising silicon carbide, PECVD silicon nitride, and PECVD silicon dioxide, respectively, formed over a bulk low dielectric constant interlevel dielectric prior to forming the interconnect structures in the interlevel dielectric. The protective hardmask 40 has a low dielectric constant k which may be the same or similar to that of the bulk dielectric layer 30.</p> |
