Water etch

Depth profile and total content of oxygen in PE was determined by RBS method. The profiles of plasma-treated sample and that subsequently etched in water are compared in Figure 9. The mean oxygen contents in the surface layer accesible by RBS, ca 140 nm thick, are (39 5) and (28 3).10 cm" for plasma-treated and water etched samples respectively. Both concentration profiles exhibit a maximum at the depth of ca 20 nm, further the concentration decreases slowly, falling to negligible concentrations at 60 nm. Similar trend was observed in previous report dealing with PE exposed to Ar plasma at the power of 1.7 W [70]. 

Figure 9. Concentration depth profiles of oxygen obtained from RBS measurement of plasma-treated PE and that of plasma-treated and water etched for 24 hours [78].

Table 3.C (Is) a O (Is) concentrations (at. %) determined from XPS measurements and radical densities (R, 10 g ) determined by EPR method. The concentrations and densities were determined on the pristine PE, plasma-treated PE (1 or 24 hours after the treatment) and plasma-treated and water etched PE (see left hand side of the table). Before the measurement the samples were stored under standard laboratory conditions [78]...

Table 4. Result of evaluation of XPS C(ls) peak for the PE samples 1 and 24 hours after the plasma treatment and plasma treated PE sample subsequently water etched for 24 hours. Concentrations of selected groups...

Above described results prove that plasma treatment of PE leads to cleveage of molecular chain and production of polar groups. Since these changes may enhance interaction with polar solvents, the water etching of modified PE was examined the calculated thickness of the surface layer removed from plasma-modified PE (240 s, 8.3 W) by 24 hour water etching is 20.6 4.6 nm [78]. 

It was observed elsewhere that plasma treatment of polymer macromolecules results in their cleavage, ablation, alterations of chemical structure and thus affects surface properties e.g. solubility [75]. The effects of the treatment in Ar plasma on the surface properties of PE were examined in [72]. The parameters of the plasma discharge (240 s, 8.3 W power) were chosen, on the basis of our previous experiments [70-74,78], to guarantee the most pronounced changes of polymer surface. Mean thickness of the ablated PE layer was calculated from the weight difference measured by gravimetry. By Ar plasma (8.3 W, 240 s) 30 8 nm thick surface layer is ablated and thickness of the surface layer removed from plasma-modified PE by 24 hour water etching is 21 5 nm [78]. 

Figure 14. AFM images of pristine, plasma-modified and plasma-modified and water-etched PE. Ra is the surface roughness in nm [78].

Compared with conventional photolithography, laser drilling is a dry process and keeps the surface of polyimide gate dielectric layer away from water, etching solution, or other solvent, which often degrade the polyimide surface. We have confirmed that the electronic performance of transistors with laser via holes is identical with that without laser via holes. 

Desalination of seawater and brackish water Electroplating rinse water Etch bath rinse water... 

Formula weight 158.11. Ruby-red bipyramlds, readily soluble in water. Etches glass vessels in which it is stored. Crystal structure tetragonal (space group Cfh). 

Photograph 1-4 UPC in Aspdin paste. Water etch reveals dark-blue, coarsely crystalline aluminate, presumably C3A. (S A6609)... 

A. Water etch (distilled water) in the pH range of 6.5 to 7.0 reacts rapidly with C A to form an interference film on the CjA that produces a bluish color when viewed through a reflected-light microscope. The procedure must be followed closely because other colors may appear with shorter etch times or slightly different acidities. Although the fluoroaluminate compound sometimes also reacts to produce a faintly visible brownish purple hue, this particular reaction is not used for positive identification. 

B. Potassium hydroxide is used for detection of fluoroaluminate. The section surface should be repolished after the water etch. The freshly polished clinker surface is then exposed to 0.1-molar potassium hydroxide solution for 30 seconds. The fluoroaluminate compound is identified by the definitive brownish purple interference color that is deeper in hue and sharper in outline than the one that, as mentioned, is sometimes visible after the 30 second distilled water etch. 

Weak water-etch response Dead burned (Hamilton, personal communication, 1998)... 

Photograph 7-79 Free-lime nest colored by water etch in polished section. Chemical analysis gave clinker free-lime value of 2.69%. High maximum temperature, moderately long burning time, moderately slow heating rate, moderately slowly cooled, 31 MPa. Gas-fired, dry-process kiln, 3000 tons/day. (S A6697)... 

Curve 5 in Figure 7.7 demonstrates the use of IRRAS to monitor the purity of metallic surfaces before chemical modification. The samples were polished with diamond paste, washed in CCI4 and hot water, etched in HNO3 in order to remove the damaged layer, swilled in bidistilled water, and then annealed for 1 h in an oil-free vacuum at f = 200°C. The spectra show only the bands of the natural oxides and no bands from impurities. 

The substrate was cold-rolled steel (CRS), provided by a steel producer. The coupons were degreased with acetone, washed with distilled water, etched in a solution of 10% HNO3 for 2 min at approximately 50°C, washed twice with distilled water, then dried prior to immersion in the silane solution containing the nanoparticles for 10 s. Finally, the treated coupons were cured in an oven at 120 C for 40 min. 

Standard 50%—most suitable for industrial bleaching, processing, pollution abatement, and general oxidation reactions. Semiconductor Reg. Seg, 50%—conforms to ACS and Semi Specs, for water etching and cleaning, and applications requiring low residues,... 

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