This work investigates the thermal stability and physical and barrier properties of two species of plasma-enhanced chemical vapor deposited (PECVD) -SiC:H silicon carbide films (with k-values less than 5) deposited using trimethylsilane, (CH 3 ) 3 SiH (3MS) and tetramethylsilane, (CH 3 ) 4 Si (4MS) organosilicate gases. It is found that the 4MS -SiC:H film contains a higher content of carbon and has a lower dielectric constant. Both of the 3MS and 4MS -SiC:H films are thermally stable at temperatures up to 500 C. However, degraded barrier property and moisture resistance were observed for the 4MS -SiC:H film; this is attributed to the porosity enrichment caused by the film's high carbon content. The 3MS -SiC:H film, which exhibits a superior Cu-barrier property, is a potential candidate for replacing the higher dielectric constant Si 3 N 4 film as a Cucap barrier and etching stop layer in the Cu damascene structure.

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This work investigates in the first place, the improvement in leakage current and breakdown field of the copper metal-insulatorsemiconductor ͑Cu-MIS͒ capacitor with a plasma-enhanced chemical vapor deposited ͑PECVD͒ amorphous silicon oxycarbide ͑␣-SiCO, k ϭ 3.7) dielectric barrier. This is followed by investigating the improvement in leakage current and breakdown field of the Cu-comb capacitor with a carbon-doped low-k PECVD organosilicate glass (k ϭ 3) as the intermetal dielectric and an ␣-SiCO dielectric film as the Cu cap barrier. The leakage current and breakdown field of Cu-MIS and Cu-comb capacitors are dependent on the species of the dielectric barrier. The Cu-MIS and Cu-comb capacitors with an ␣-SiCO dielectric barrier exhibit a leakage current at least three orders of magnitude smaller than those with an amorphous silicon carbide ͑␣-SiC, k ϭ 4.4) dielectric barrier at an applied electric field of 1.6 MV/cm between 25 and 250°C. Moreover, the breakdown field of the Cu-MIS and Cu-comb capacitors with an ␣-SiCO dielectric barrier, measured at 200°C, are 60 and 25%, respectively, higher than that of the capacitors with an ␣-SiC barrier. The decreased leakage current and increased breakdown field of the Cu-MIS and Cu-comb capacitors with an ␣-SiCO dielectric barrier are attributed to the higher density, oxygen-improved film property, nonsemiconductor behavior, and lower fringe-or surface-electric field of the ␣-SiCO dielectric film.

In this work, we investigate the effects of oxygen (O 2 ) and nitrogen (N 2 ) plasma treatments on the copper surface of aluminum/amorphous silicon-nitricarbide/copper (Al/-SiCN/Cu) metal-insulator-metal (MIM) capacitors with respect to their leakage current and breakdown field. It is found that both the O 2 -and N 2 -plasma treatments have an adverse effect on the leakage current and breakdown field of MIM capacitors. The MIM capacitors with their Cu surfaces subjected to O 2 -or N 2 -plasma treatment exhibit a room-temperature leakage current density several orders of magnitude larger than that of the sample without plasma treatment at the same applied electric field. The room-temperature breakdown fields of the MIM capacitors with O 2 -and N 2 -plasma-treated Cu surfaces are 3.8 and 3.2 MV/cm, respectively, while that of the control sample without plasma treatment is 7.8 MV/cm. The increased leakage currents and degraded breakdown fields of the O 2 -and N 2 -plasma-treated samples are attributed, respectively, to the presence of metastable Cu-O oxide and Cu-N azide at the Cu surfaces.

This work investigates the leakage and breakdown mechanisms in copper ͑Cu͒ comb capacitors with carbon-doped low-k plasmaenhanced chemical vapor deposited organosilicate glass ͑OSG; k ϭ 3) as the intermetal dielectric and an ␣-SiCN (k ϭ 5)/␣-SiC (k ϭ 4) bilayer-structured dielectric film as the Cu-cap barrier. The leakage mechanism between Cu lines is dependent on the thickness ratio of the ␣-SiCN/␣-SiC bilayer barrier. Using an ␣-SiCN/␣-SiC bilayer barrier of 40 nm/10 nm or 30 nm/20 nm bilayer thickness, the increased leakage current ͑Frenkel-Poole emission͒ between Cu lines is attributed to the large number of interfacial defects, such as cracks, voids, traps or dangling bonds at the ␣-SiC/OSG interface, which are generated by the larger tensile force of the thicker ␣-SiC film. The Cu comb capacitor with an ␣-SiCN ͑50 nm͒/␣-SiC ͑2 nm͒ bilayer barrier exhibits a much smaller leakage current. The breakdown field and time-dependent dielectric breakdown lifetime of the Cu comb capacitor reveal little dependence on the thickness ratio of the ␣-SiCN/␣-SiC bilayer barrier, and the observed breakdown of the Cu comb capacitor is presumably due to dielectric breakdown of the bulk OSG layer.As the interconnect resistance-capacitance ͑RC͒ delay becomes a dominant factor in determining the performance of integrated circuits, the advantages of Cu metal and low-k dielectrics become more remarkable. Cu metal reduces the electrical resistance of interconnection lines because of its low electrical resistivity; moreover, Cu line also exhibits a better electromigration resistance than the conventional Al-based wires. The use of low-k dielectrics in the interconnect system reduces the wire capacitance, signal-propagation delay, cross talk-noise between metal lines, and power dissipation of integrated circuits. While many low-k (k Ͻ 3) materials have been used as inter-and intralayer dielectrics ͑ILD͒, high-dielectricconstant (k Ͼ 7) silicon nitride is still the primary candidate for the Cu-cap barrier and etching stop layer ͑ESL͒ required in the Cu damascene structure. It is desirable to replace silicon nitride with dielectric materials of lower k-value (k Ͻ 5) in order to further reduce the effective dielectric constant of the Cu interconnect system. In recent years, amorphous silicon carbides ͑␣-SiC͒ and amorphous silicon-nitricarbide ͑␣-SiCN͒ deposited by plasma-enhanced chemical vapor deposition ͑PECVD͒ using organosilicate gases ͑OSG͒ are receiving extensive attention for applications as Cu-cap barriers and ESL in Cu interconnection schemes because of their lower k-value, better etching selectivity with OSG, robust chemical mechanical polishing ͑CMP͒ strength, good photoresist poisoning resistance, higher antireflective ability, and superior properties as a Cu barrier/passivation layer in terms of Cu restraint, electromigration resistance, and Cu-hillock density. 1-3 There are a number of studies on the electrical reliability of the ␣-SiC and ␣-SiCN films with respect to their integration with Cu using planar metalinsulator-se...