Spray acid tool

Experiments 9-12 explore the use of an SAT (spray acid tool, which rotates the wafers during cleaning) with SCl-HF with various concentrations. We found out that none of the experimental conditions yielded acceptable electrical data. Both SCI and HF corroded W plugs. Experiments 13 and 14 use SAT and novel chemicals that is, TMAH (N(CH3)40H, tetramethyl ammonium hydroxide), and/or NH4F (ammonium fluoride). These results were the best in terms of both the Fe contamination and the W plug compatibility. 

The one-sided scrubber, spin-rinse-dry (SRD), or spray acid tool (SAT). 

The use of surface-enhanced resonance Raman spectroscopy (SERRS) as an identification tool in TLC and HPLC has been investigated in detail. The chemical structures and common names of anionic dyes employed as model compounds are depicted in Fig. 3.88. RP-HPLC separations were performed in an ODS column (100 X 3 mm i.d. particla size 5 pm). The flow rate was 0.7 ml/min and dyes were detected at 500 nm. A heated nitrogen flow (200°C, 3 bar) was employed for spraying the effluent and for evaporating the solvent. Silica and alumina TLC plates were applied as deposition substrates they were moved at a speed of 2 mm/min. Solvents A and B were ammonium acetate-acetic acid buffer (pH = 4.7) containing 25 mM tributylammonium nitrate (TBAN03) and methanol, respectively. The baseline separation of anionic dyes is illustrated in Fig. 3.89. It was established that the limits of identification of the deposited dyes were 10 - 20 ng corresponding to the injected concentrations of 5 - 10 /ig/ml. It was further stated that the combined HPLC-(TLC)-SERRS technique makes possible the safe identification of anionic dyes [150],... 

Tablets. SEM was widely used to investigate the structure of tablets. An excellent review is presented by Hess. " Imaging of tablets is a useful tool to demonstrate differences in compression behavior of substances. Fig. 24 shows an example where the plastically deforming spray-dried sorbitol instant was compressed together with the more brittle ascorbic acid in one tablet. At low compressional force of 5 kN for a 10 mm tablet, the rectangular ascorbic acid crystals as well as the partially deformed sorbitol particles are visible (Fig. 24A). In Figs. 24A and B, the surfaces of two tablets compressed at 5 kN and 30 kN are compared. At higher compressional forces, a uniform, flat, and smooth tablet surface is formed, but within this surface a single unchanged ascorbic acid crystal could be detected. Observation of a broken tablet (Fig. 24C), which was prepared at a high compressional force of 30 kN, reveals that the ascorbic acid crystal is totally fixed within a matrix of plastically...

Similar problems arise with many metal working fluids. These are sprayed onto the cutting tools, fall into an open collecting vessel, and are recirculated. They are frequently contaminated with organic detritus such as food crumbs, and mice or rat faeces or urine. They may be topped up periodically with fresh oil and maintained at temperatures of 20-30 °C leading to rapid deterioration. The effect of bacterial metabolism is to break the emulsion into organic and aqueous layers, the oil is converted into fatty acids, the pH falls the emulsion becomes useless and may cause corrosion spots on the finished item. 

TLC is a simple, inexpensive technique that can be effectively used for the analysis of natural products including quassinoids. In addition to being used as an analytical tool, TLC is also used to partially purify and isolate quassinoids as in colunui chromatography. The effectiveness of the separation depends on the extract, choice of mobile phase, and absorption layer such as silica gel, alumina, cellulose powder, polyamides, and ion-exchangers supported on glass or metal plate. Rf values or the retention factor is commonly used to describe chromatographic behavior and is defined as distance moved of a particular spot divided by the distance moved by the solvent front. Comparative Rf values can be utilized to analyze extracts both qualitatively and quantitatively. Quassinoids give red color on TLC plate when sprayed with concentrated sulfuric acid and brown when heated. Various stationary and mobile phases have been utilized in the separation of quassinoids, viz. ... 

In some of the experiments, a lubrication system (Unist Standard Cool-Lubricator) was used to provide a continuous supply of lubricant onto the rake face. This supply, in the form of an air-mist, was controlled by an air metering screw. The cutting fluid, Cool-Lube 2210, was delivered to the tool rake face as a spray through a mix nozzle that was coupled to a co-axial air hose. Cool-Lube 2210 (Triglycerol Propylene glycol esters of C8 CIO acid) is a vegetable-based metal cutting lubricant. 

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