Low-Temperature Fabrication of Nickel Silicide Metal Oxide Semiconductor Capacitors at 280 °C by Metal Chloride Reduction Chemical Vapor Deposition

Abstract

We have successfully fabricated nickel silicide metal-oxide-semiconductor (MOS) capacitors at 280 C by metal chloride reduction chemical vapor deposition (MCR-CVD). In this process, we first prepared polycrystalline silicon (poly-Si)/SiO 2overcoated Si wafers and exposed the wafers to Cl plasma containing NiCl for 40 min with a substrate temperature of 280 C. During this process, the top layer of poly-Si is changed to a nickel silicide film with the Ni concentration at approximately 50%. Depth-resolved X-ray photoelectron spectroscopy (XPS) showed a uniform profile of the top film and a sharp interface on the SiO 2 surface at such Ni concentration. We have also obtained capacitance-voltage (C-V) characteristics using a MOS capacitor from the processed wafer. We demonstrate the possibility and applicability of MCR-CVD in the near room temperature (RT) fabrication of metal gate MOS capacitors.

Nanoindentation Behaviour and Annealed Microstructural Evolution of Ni/Si Thin Film

“…13,33) Similar results are reported by Oyama et al 34) and Kittl et al; 35) Oyama et al 34) develop a silicidation process for fabricating nickel silicide gate capacitors using a unique cl plasma process of metal chloride reduction chemical vapor deposition (MCR-CVD) at low temperatures below 300 C. Kittl et al 35) use an optimized 2-step rapid thermal process (RTP) to form NiSi gates at temperature of 300 C. Both two processes show that the NiSi phase can be obtained by simple solid phase diffusion method at low temperatures of approximately 300 C. Note that NiSi phase belongs to the orthorhombic structure, with lattice parameters a ¼ 0:523 nm, b ¼ 0:326 nm, and c ¼ 0:566 nm. 36) Interestingly, the Ni 2 Si peak at 140 cm À1 is no longer observed, which suggests that the Ni 2 Si phase changes to NiSi as the annealing temperature is increased.…”

Tungsten Deposition by Metal-Chloride-Reduction Chemical Vapor Deposition

“…In MCR-CVD, it is likely that the Cl radical etches solid metal at higher temperatures while it reduces the metal chloride at lower temperatures. [8][9][10][11][12] In the present work, the temperature difference of the solid W (800 C) and the substrate ($ 500 C) enables the continuous W deposition on the substrate. The film crystallinity of the grown W film was evaluated by xray diffraction.…”

“…5 In the field of Cu CVD for metal wiring in the LSI production, on the other hand, Sakamoto et al developed a unique metal CVD using metal chloride reduction (MCR). [8][9][10][11][12] In this process, bulk metal is exposed to Cl radicals to produce metal chloride species in the reaction chamber. The metal chloride species are delivered as gas molecules to the wafer to be reduced by the additional Cl radicals, where the pure metal film is grown on the surface.…”

“…11 We also developed a low-temperature NiSi fabrication process for metal-gate FETs with MCR-CVD. 12 In the present work, we have newly developed a W deposition process with the Cl plasma containing W chlorides based on MCR-CVD. This process enables the deposition of W with very low resistivities in the order of 10 À5 X cm.…”

High-Quality Nickel Silicide MOS Capacitors Fabricated with a Cl Plasma Containing NiCl

“…One of the present coauthors, on the other hand, has developed a metal formation process of Cu by metal chloride reduction chemical vapor deposition (MCR-CVD) [2]. In the present work, we have newly developed a unique method of Ni silicidation with a Cl plasma containing NiCl based on MCR-CVD [3]. The present technique enables the low temperature process below 300 C, down to 200 C, and the concentration control of Ni in the grown film.…”