Substrate evaporation deposited copper

Substrate/Evaporation Deposited (EVD) Copper or Silver/Electrocopper (EVD Process)... 

Photochromic silver—copper haUde films were produced by vacuum evaporation and deposition of a mixture of the components onto a sUicate glass substrate (13). The molar ratio of the components was approximately 9 1 (Ag Cu) and film thicknesses were in the range of 0.45—2.05 p.m. Coloration rate upon uv exposure was high but thermal fade rates were very slow when compared with standard silver haUde glass photochromic systems. 

A procedure involving (a) the deposition of nearly stoichiometric films of copper and indium on suitable substrates using vacuum evaporation or electrodeposition and (b) the heat treatment of Cu-In films in a hydrogen-selenium atmosphere at temperatures above 630 °C was reported to yield large grain (several mm in size), stoichiometric thin films of chalcopyrite CIS with a preferred 112 orientation [167]. 

Fig. 13.20. Optical heterodyne force microscopy (OHFM) and its application to a copper strip of width 500 nm, thickness 350 nm, on a silicon substrate, with subsequent chemical vapour deposition (CVD) of a silicon oxide layer followed by polishing and evaporation of a chromium layer of uniform thickness 100 nm and flatness better than 10 nm (a) amplitude (b) phase 2.5 [im x 2.5 m. Ultrasonic vibration at fi = 4.190 MHz was applied to the cantilever light of wavelength 830 nm was chopped at fo = 4.193 MHz and focused through the tip to a spot of diameter 2 im with incident mean power 0.5 mW the cantilever resonant frequency was 38 kHz. The non-linear tip-sample interaction generates vibrations of the cantilever at the difference frequency f2 — f = 3 kHz (Tomoda et al. 2003).

Since one of the issues raised in this paper is whether the objects seen in the TEM images are a proper representation of the structures present in solution, we will describe briefly sample preparation strategies. For solutions of micelles in hexane, a very volatile solvent, samples for TEM studies could be obtained by aspirating a dilute solution directly onto a carbon-coated copper grid. Most of the solvent likely evaporated as the sample was deposited on the substrate. Alternatively, the TEM substrate could be dipped briefly into a dilute solution of the micelles and allowed to dry. This method also worked for less volatile solvents like decane. For decane, we could also place a small drop (a few pi) of solution on the grid and then touch the edge of the droplet with a Kimwipe to remove excess solvent. For several samples these methods were compared, and we observed the same morphology. 

Samples were made in the following way. The bottom copper electrode in the form of a strip is deposited on a glass substrate by the vacuum thermal evaporation through a shadow mask with area of 1 x 10 mm. The thin polymer films were prepared by the spin coating from 5% polymer solution, in cyclohexanone. Immediately after spinning the samples were thermally dried for 3-4 h at 150°C before deposition of the electrode. Middle and upper copper electrodes were prepared in the same way. The middle polymer layer was placed between the second and third electrodes and was made similar to the first polymer layer. Thickness of the polymer layers was about 500 nm, the thickness of metal electrodes did not exceed 100 nm. The active area between three electrodes was 0.01 cm ... 

The second type of films used in UHV studies of SERS are the films deposited onto cold substrates. Wood and Klein evaporated silver (unknown thickness) on a copper substrate cooled to 78 K and detected a surface Raman signal at 2134 cm (presumably, associated with adsorbed CO or carbonate) which was independent of CO pressure. That band was seen together with... 

The typical polymer LED structure is shown in Figure 7.3. In order to fit in the quartz finger dewar which is inserted in the microwave cavity (see Section 1.3.1 below), the width of the devices was limited to 4.5 mm. They were all fabricated on ITO-coated glass, which was the positive electrode. The active area of the devices was 7 mm. PPV layers were deposited by spin coating the appropriate precursor and thermally converting it CN-PPV was spin-cast directly from solution [3]. The deposition of the polymers was followed by evaporation of the metal electrode from which electrons were injected into the devices [3,9,25,26,28,29]. In the case of the PPV- and PPE-based devices, that electrode was Al-encapsulated Ca, which yielded a higher device efficiency than an A1 electrode [9,25,26,28,29]. The thickness of the emissive PPV and PPE layers was 600 and 300 nm, respectively. Derivatives of PPE dissolved in toluene were spin-coated onto the ITO substrates, followed by e-beam or thcnnal evaporation of A1 or Ca/Al electrodes in a base chamber pressure of 10 torr. The PPV/CN-PPV diodes used A1 as the electron-injecting electrode [3], The thickness of the PPV layer was 120 nm, and that of the CN-PPV layer was 100-200 nm. Finally, copper wires were bonded to the A1 and no layers with silver paint. 

Polymer substrates were also metallized by evaporation. Prior to metal deposition, the specimens were cleaned in a 2 % aqueous detergent, rinsed and dried. A resistively-heated conical tungsten basket containing 99.99+ % purity copper foil served as the metal source. Typically 100-200 nm of metal was deposited in an Edwards E306A coating system. The chamber was evacuated to 2 x 10 4 Pa and held for at least 1 h prior to metal deposition in order to properly degas the substrates. Complete details of the evaporation procedure have been given previously... 

Depending on the metal deposited, the lift-off process may vary. Copper is insoluble in an aqueous solution, therefore the etching mask needs to be removed by dipping the substrate in an appropriate stripping solution. However, because aluminum dissolves in both acid and alkaline solutions, following the evaporation of this metal, a photoresist layer is normally applied and patterned to protect the desired metal in vias/channels. This protection layer is stripped off after the lift-off mask is removed. Note that the photoresist layer in this process must withstand whatever solution is used to etch the RIE mask. This technique produces a truly planar surface for the next layer. 

Copper can be electroplated onto the substrate in two techniques. In the first process, as shown in Figure 8.25a, an adhesion or seed layer is deposited on the ceramic. This adhesion layer can be thin film, either sputtered or evaporated, thick film, or refractory metallization. A sputtered or evaporated gold layer is deposited on top of the seed layer for thin-film metallization. Copper is then electroplated to the required thickness. This is followed by electroplated nickel and an optional gold electroplate. Figure 8.26 shows the buildup of plated copper metallization. 

---