Conformal Deposition and Gap-Filling of Copper into Ultranarrow Patterns by Supercritical Fluid Deposition

Abstract

Supercritical fluid deposition (SCFD) of Cu onto ultranarrow vias (50 to 220 nmφ and 1 µm depth) was studied with using angled polishing for future ultralarge scale integration metallization. SCFD conformally fabricated a smooth, continuous, and 10-nm-thick Cu film in ultranarrow vias. Excess H2 compared with the precursor as well as surface saturation of the precursor enabled uniform nucleation and conformal deposition. Highest H2 concentration in this study (0.39 mol/L) promoted the nucleation density, resulting in formation of a smooth and continuous film. In conclusion, SCFD successfully achieved complete filling without any voids onto via patterns.

The effects of supercritical CO2 formulations on the removal of high-dose ion-implanted photoresists

“…4, the stripping efficiency was found to be dependent on the temperature at the constant pressure (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). The stripping rate increased with the elevated temperature below 60°C, while the reverse results were obtained at 70°C and 80°C.…”

“…The properties of near zero surface tension and tunable solvating ability in conjunction with its advantages of moderate critical temperature and pressure, nonflammability, ease of availability, low cost, and being environmentally benign render scCO 2 an attractive solvent in a variety of applications in microelectronic manufacturing [11][12][13]. scCO 2 can easily penetrate into small holes, polymer films, and the interfaces between photoresist and the underlying substrate due to its low surface tension.…”

Step Coverage Quality of Cu Films by Supercritical Fluid Deposition Compared with Chemical Vapor Deposition

“…For example, a smooth, continuous, 10-nm-thick Cu film has been fabricated when nucleation was enhanced by increasing the introduced H 2 concentration. 7) In summary, superior SC of SCFD and CVD was achieved by different factors. In SCFD, non-linear deposition kinetics realized at higher precursor concentration contributed to conformal deposition, although mass transfer in SCF was lower than that in vacuum.…”

“…For example, using higher precursor concentration and higher diffusivity of bis(2,2,6,6-tetramethyl-3,5-heptanedionato)-copper [Cu(tmhd) 2 ], we successfully demonstrated formation of a smooth, continuous, 10-nm-thick film and complete gap-filling of Cu into ultra narrow vias. 7) Successful metal filling onto fine features by SCFD have been reported. 2,3,[7][8][9][10][11][12][13] To date, however, the potential of conformal deposition and gap-filling by SCFD has not been quantitatively evaluated.…”

Supercritical CO2 reactor for wafer-scale thin film deposition: reactor concept, numerical results, and Cu depositio.

“…One example of a chemical formulation of this reaction is ML 2 + H 2 → M + 2HL, where M refers to the metal and L is a ligand. The excellent capability of this technique for filling narrow features, such as nanopores [12][13][14][15], nanotrenches [2,3,16], and nanoholes [16,17], with a metal has been demonstrated successfully, which suggests that this technique may be applicable to the fabrication of small interconnects.…”