CVD Cu

Fig. 38 Through-mask deposition process, (a) Substrate, (b) PVD or CVD Cu seed layer deposition, (c) photoresist deposition and patterning, (d) through-mask electroless deposition of Cu,...

Figure 1.3. Comparison between PVD and CVD processes (a) PVD coating on a step substrate, (b) CVD TiN on a step Si substrate [3] and (c) CVD Cu into a micro-trench [4]...

Fig. 1.24. A schematic of the damascene process involving (a) dry-etching of trenches in the silicon oxide insulator and the deposition of an adhesion layer of TiN which also serves as an oxidation and diffusion barrier for Cu, ( ) plugging the trenches with CVD-Cu, and (c) chemical-mechanical polishing of Gu.

Copper is an attractive metallisation element because of its high conductivity. It has been added to Al in low concentrations (AlSi(l%)—Cu(0.5%)) to improve conductive priorities. Selective, low temperature copper CVD processing, using copper(I) P-diketonate compounds, has been carried out (23). 

A typical example of the complexity of interconnection assembly consists of a MOCVD-TiN diffusion barrier combined with a low-temperature (260°C) CVD aluminum with low resistivity (<3 lQ-cm). A copper doping forms an overlying sputtered Al-Cu film. This aluminum plug provides a large reduction in resistance compared to the classical tungsten process. k" ... 

Zinc sulfide, with its wide band gap of 3.66 eV, has been considered as an excellent electroluminescent (EL) material. The electroluminescence of ZnS has been used as a probe for unraveling the energetics at the ZnS/electrolyte interface and for possible application to display devices. Fan and Bard [127] examined the effect of temperature on EL of Al-doped self-activated ZnS single crystals in a persulfate-butyronitrile solution, as well as the time-resolved photoluminescence (PL) of the compound. Further [128], they investigated the PL and EL from single-crystal Mn-doped ZnS (ZnS Mn) centered at 580 nm. The PL was quenched by surface modification with U-treated poly(vinylferrocene). The effect of pH and temperature on the EL of ZnS Mn in aqueous and butyronitrile solutions upon reduction of per-oxydisulfate ion was also studied. EL of polycrystalline chemical vapor deposited (CVD) ZnS doped with Al, Cu-Al, and Mn was also observed with peaks at 430, 475, and 565 nm, respectively. High EL efficiency, comparable to that of singlecrystal ZnS, was found for the doped CVD polycrystalline ZnS. In all cases, the EL efficiency was about 0.2-0.3%. 

Cu-Zn system, shape-memory effect in, 22 343. See also Copper entries CVD-deposited films, properties of,... 

Fig. 5.14 (a) Schematic of SEED process of metal NP deposition on metai surface supported nanoparticie. (b) Example of Au NP deposition on CVD grown graphene on Cu foil, scale 1pm. Reproduced with permission from [143], (2012) Elsevier. 

Figure 19.5. Process sequence for the lift-off process (the planarized metalhzation process) (a) a resist film is patterned on a dielectric film (b) dielectric patterning (c) a thin catalytic film layer (PVD or CVD Ti, Al) is deposited (d) a lift-off technique removes the excess material, leaving the catalytic layer in the trench only (e) electroless Cu deposition.

In particular, CVD of the derivatives Cu(hfac)(PMe3),1,2 Cu(hfac)(l,5-cod),3-6 Cu(hfac)(2-butyne),7,8 and Cu(hfac)(vtms),9-12 where 1,5-cod = 1,5-cyclooctadiene and vtms = vinyltrimethylsilane, has been studied in detail. These species can be used to deposit copper films either selectively or nonselectively on various surfaces depending on the nature of the precursor, the deposition conditions, and the substrate surface pretreatment. The syntheses of these species from a general salt elimination reaction according to eq. (2) is described here in detail.10,13,15-17 It should be noted that other general methods of preparation of this class of compounds have been reported elsewhere.18... 

A large class of coordination compounds, metal chelates, is represented in relation to microwave treatment by a relatively small number of reported data, mainly p-diketonates. Thus, volatile copper) II) acetylacetonate was used for the preparation of copper thin films in Ar — H2 atmosphere at ambient temperature by microwave plasma-enhanced chemical vapor deposition (CVD) [735a]. The formed pure copper films with a resistance of 2 3 pS2 cm were deposited on Si substrates. It is noted that oxygen atoms were never detected in the deposited material since Cu — O intramolecular bonds are totally broken by microwave plasma-assisted decomposition of the copper complex. Another acetylacetonate, Zr(acac)4, was prepared from its hydrate Zr(acac)4 10H2O by microwave dehydration of the latter [726]. It is shown [704] that microwave treatment is an effective dehydration technique for various compounds and materials. Use of microwave irradiation in the synthesis of some transition metal phthalocyanines is reported in Sec. 5.1.1. Their relatives - porphyrins - were also obtained in this way [735b]. 

In summary, CVD aluminum films produced by low-pressure pyrolysis of TIBAL have been shown to achieve the improved conformality desired. Unfortunately, they are rougher than standard films, and no feasible way of introducing Cu into the film has been found to prevent electromigration. 

Following these studies, a microstructure of sputter-deposited ZnO films on polycrystalline CdS substrates is outlined in Fig. 4.21. The different evolution of the Zn 2p and O Is binding energies can consequently be attributed to the amorphous ZnO nucleation layer with a different chemical bonding between Zn and O. The model is also valid for polycrystalline In2S3 and Cu(In,Ga)Se2 substrates and for deposition of (Zn,Mg)0 films, as these show the same behavior (see Figs. 4.20 and 4.24). It is not clear whether an amorphous nucleation layer occurs also when the ZnO is deposited by other techniques as MBE, CVD, or PLD, as no data are available for such interfaces. In addition, the influence of the polycrystallinity of the substrates is not clear so far. 

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