Electroless annealing

Films of CoB have been prepared by electroless deposition. Chang et al. [25] deposited magnetically soft amorphous films, which could be annealed to give materials with an Hc of 250 Oe. Depending on the annealing temperature, the films crystallized as the hep or fee modifications of Co. Matsui and co-workers [22] obtained crystalline materials in the as-deposited state, the crystalline characteristics being determined by processing conditions. A maximum HQ of 300 Oe was observed for films with 10.0 preferred orientation. 

A comparison was made between Ni and Co diffusion barriers produced by electroless, electro-, and evaporation deposition (64). This comparison shows that only electrolessly deposited metals and alloys, at a thickness of 1000 im, have barrier properties for Cu diffusion. For Co(P) 1000-pm-thick barriers, annealed for 14h, the amount of Cu interdiffused into Co(P) is less than 1 at %. Thicker barriers of Ni(P), Ni(B), and Co(B) are required for the same degree of Cu interdiffusion. The same metals, if electrodeposited, both do and do not have inferior barrier properties. This... 

Fig. 17. Effect of the annealing temperature on the specific resistance of electroless Nig,W7Pj2, Ni5,Re44P5, NiggMoijPi, and Ni7( P24 alloy films Osaka et al., 1992 [38]).

It has long been known that the ductility of electroless copper can be increased by annealing at relatively low temperatures, and that the hydrogen content of the deposit decreases upon annealing. The existence of a close correlation between the two annealing effects has been demonstrated [141]. Fig. 24 shows an example of the variation of the ductility (% elongation determined by a mechanical bulge tester)... 

Fig. 15.20 Sheet resistances of electroless Ni-alloy films as a function of annealing temperature. Cu layer was deposited by evaporation on electroless Ni-alloy film...

It was reported that the presence of a strong (111) crystallographic structure is one of the important parameters that affect the electromigration performance of the interconnect lines [3,4], Thermal annealing is an integral processing step in wafer fabrication and the heat treatment can modify the crystal microstructure and the electrical properties of electroless deposited Cu. 

The objective of this work is to compare the oxidation behavior of electroless deposited Cu at different annealing conditions. The variations of the microstructures of electroless deposited Cu films were studied using both Scanning Electron... 

Microscope (SEM) and Atomic Force Microscope (AFM). The variation of the crystallinity was analyzed using X-Ray Diffraction Spectroscopy (XRD). The element concentration of the annealed electroless plated films was investigated using Energy Dispersive X-Ray Spectroscopy (EDX). 

Fig. 1 and Fig. 2 are the SEM micrographs of as-deposited and annealed electroless deposited Cu films after annealing for 25 minutes at 300°C in inert (nitrogen) ambient. It can be seen clearly in Fig. 2 that the grain sizes had increased and the grain boundaries reduced after the heat treatment. 

Fig. 2. SEM micrograph of electroless deposited Cu after annealing for 25 min at 300°C in inert/N2 environment.

Fig.6. XRD of electroless deposited Cu after annealing at 200°C for 30 min in vacuum (10 6 Torr).

P Screen printing baking at 240 °C in inert ambient firing at 725 °C in air annealing at 450 °C in N2 —> Ag electroless Ag Ohmic Specific contact resistance 1.025 x lO " (before electroless Ag deposition) 3.25 X 10 (After electroless Ag deposition) Vinod2013... 

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