IC Metallization

For more information, we refer to some excellent reviews by Paull, and king Galli et al. and Baena et ah and a more recent update from Timerbaev. Pacakova et al. reviews the importance of CE, capillary electrochromatography, and IC. Metal ions have been reviewed by Timerbaev and shipgin and by Macka and Haddad. 

If a reactant is an -ic metal ion, there is implied the existence of a lower valence form and thus the possibility that the reactant is an oxidizing agent. 

The results of hard metal capping schone (a) with anisotrc ic metal deposition and (b) without anisotropic metal deposition. 

United Kingdom Ceres Power (spin-off from Imperial College) 16 planar, CGO electrolyte for 550 C, metallic IC, metallic substrate sealing, cell, stack, manufacturing, system... 

Increasing the nanoparticle loading on the latex spheres via the autocatalj ic metal deposition previously described [35, 36]. 

Figure 10.1.3. Intensity ratio vs DN and AN. [Adapted, Figure 10.1.4. PMMA surface content vs. intensity ratio, by permission, from M L Abel, M M Chehimi, [Data fiorn M L Abel, M M Chehimi, 5yntAe

The principle of indirect electrolysis using a redox couple is shown in Fig. Ic. Metal ions in acidic solutions are oxidized on the anode from their stable oxidatirui state to the higher... 

Ic Metallized carbon Thin metal overcoating on a carbon fiber. 10 -10 ... 

Figure 5. Type Ic, metallized (nickel coated) carbon fiber at 3000X magnification (INCO Europe Ltd).

Ruthenium has a marked tendency to interaction with phenyl groups in PPha by c>rr/ic>-metallation. Thus it is not surprising that [RuH2(PPh3)3] is an effective catalyst for the hydrogenation of naphthalene to tetrahydronaphthalene/ ... 

Another important application area is the non-destructive defectoscopy of electronic components. Fig.2a shows an X-ray shadow image of a SMC LED. The 3-dimensional displacement of internal parts can only be visualized non-destructively in the tomographic reconstmction. Reconstructed cross sections through this LED are shown in Fig.2b. In the same way most electronic components in plastic and thin metal cases can be visualized. Even small electronic assemblies like hybrid ICs, magnetic heads, microphones, ABS-sensors can be tested by microtomograpical methods. 

It should be noted that typical values for for simple metals like sodium or potassium are of the order of several electronvolts. If one defines a temperature, Jp, where Jp = E /lc and Ic is the Boltzmaim constant,... 

Metallization. Integrated circuits require conductive layers to form electrical connections between contacts on a device, between devices on a chip, between metal layers on a chip, and between chips and higher levels of interconnections needed for packaging the chips. It is critical to the success of IC fabrication that the metallization be stable throughout the process sequence in order to maintain the correct physical and electrical properties of the circuit. It must also be possible to pattern the blanket deposition. 

Etching. After a resist is patterned on a wafer, the exposed or unwanted substrate is removed by etching processes. Subsequentiy the resist is removed, leaving a desired pattern in a functional layer of the integrated circuit. Etching is performed to pattern a number of materials in the IC fabrication process, including blanket polysiHcon, metal layers, and oxide and nitride layers. The etch process for each material is different, and adapted to the material requirements of the substrate. 

Upon strong chelation, aU. four protons are displaced and base titration resembles that of a typical strong acid at four times the equivalent concentration. This statement is in agreement with equation 19, which shows that pM can be large (low concentration of free metal) at low pH if iC is large (strong chelation). 

Mobile ions, such as sodium or potassium, tend to migrate to thep-n junction of the IC device where they acquire an electron, and deposit as the corresponding metal on the p-n junction this consequendy destroys the device. Furthermore, mobile ions also support leakage currents between biased device features, which degrade device performance and ultimately destroy the devices by electrochemical processes such as metal conductor dissolution. 

For example, chloride and duoride ions, even in trace amounts (ppm), could cause the dissolution of aluminum metallization of complimentary metal oxide semiconductor (CMOS) devices. CMOS is likely to be the trend of VLSI technology and sodium chloride is a common contaminant. The protection of these devices from the effects of these mobile ions is an absolute requirement. The use of an ultrahigh purity encapsulant to encapsulate the passivated IC is the answer to some mobile ion contaminant problems. 

T.W. Clarkson, Effects - General Principles Underlying die To. ic Action of Metals, Handbook on the To.xicology of Metals, L. Friberg, G.F. Nordberg, and V.B. Vouk, eds. 2 ed., Elsevier, Amsterdam, Holland, 1986. 

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