Etching time

Figures 3(b) and 3(c) were the EDS results of the etched nanodot arrays shown in Figs. 2(b) and 2(c). The EDS of Fig. 3(b) was almost identical to that of Fig. 3(a). It means that niobium oxide masks were still on Si film although the Si dots were formed. Fig. 3(c) was the EDS result of the nanodot arrays etched for longer etch time than Fig. 3(b). The Nb peak disappeared due to the increased etching and it was confirmed that the nanodots consisted of only Si. The diameters of Si nanodots were approximately 20 30 nm. It was demonstrated that the optimal etching condition could form close-packed and highly ordered Si nanodot arrays without niobium oxide mask. It is expected that this novel technique of forming...

Fig. 1. SEM images of etched HfN surface in Cb with etching time (a) 10s, (b) 15s, (c) 20s, and (d) 25 s. The inset shows an evolution of surface topography (height) using AFM with various etching time X 0.25 um/div, Z 70nm/div. The experiments were performed at a pressure of lOmTorr, source power of 400W, and bias voltage of -200V.

Etch times were investigated for aluminum and SU8 sacrificial cores patterned on silicon. Samples were periodically removed from the acid etch solution, and the amount of sacrificial core that was removed was measured using an optical microscope. We found that the etch length as a function of time follows the equation... 

Amount of Tia (atoms/cm2) Before Etching After Etching Etching Time (min.) PMMA Film Thickness ( im) Initial Final Etching Rate (A/min)... 

Z/RIE Conditions flow-20 SCCM, chamber pressure-35mTorr Etch time - 1.0 minute... 

Sample Si Concen. Average pit width Etch time... 

The comparison of the resistive property in the plasma etching process between PMMA itself and PMMA sensitized by 2,4,6-tri-tert-butyl phenol is shown in Fig. 12. Following the etching tim the thickness of the PMMA coating becomes thinner. The rate of the decreasing of the film thickness is proportional to the etching time in the former case, but it becomes very slow in the case of the sensitized PMMA. Therefore, the sensitized PMMA is a superior resist than PMMA itself in both properties of the sensitivity and the resistivity. This fact is true in the cases of other sensitizers. 

The formation of a chemical oxide in pure DI water was found to depend critically on the DOC of the water [Gr3, Mol, Li9]. In DI water of very low DOC (<0.004 ppm), no native oxide forms. Furthermore the reverse reaction is observed for elevated temperatures (80 °C) and long etching times (60 min) thin native or chemical oxides are removed and a hydrogen-terminated surface is established [Wa2]. 

We first prepare a smooth surface by ion-etching the Ge crystal for 1 hom at 430°C. Subsequently, this flat surface is roughened by ion-etching at reduced temperature, 270°C [23], Etching times of 10, 42, or 180 minutes are used to produce rough sm-face morphologies with characteristic in-plane length scale L of 37, 65, and 118 mn, respectively, see Fig. 3. 

At the initial recording stage, for t < Ioptim, the depth of the etched groove is approximately proportional to the etching time t, and for t > roptim the relief depth tends to a limit (curve 3 in Fig. 22). The profile of the relief is quite close to the sinusoidal one but at the same time there is undesirable random etching of the surface that leads to a decrease in its reflectivity (curve 2 in Fig. 22). 

The etching process may be characterized by an amount of light energy received by a sample for the optimal etching time. For some semiconductor materials this amount is equal to approximately 1 J/cm2. The minimum operating illumination intensity, at which the rate of photoetching exceeds noticeably the rate of dark corrosion, is 10"4 W/cm2. 

The surface electron lines as a function of etch time are illustrated in Figure 35 for the two sets of samples. 

Etch time Ba 3s Intensity 1000 cps (min) Surface Normal Sulfur Surface 2p Intensity 1000 cps Normal... 

Figure 38 illustrates accumulated surface scans in the rhodium 3d and phosphorus 2p region taken from granules of the rhodium anchored catalyst. The surface concentration is low enough that scan accumulation was necessary to detect these elements. These particles were oxygen plasma etched for thirty minutes and Figure 39 includes a survey spectrum as well as Rh 3d and P 2p spectra taken from the sample after OPE. The intensity of the rhodium and phosphorus lines is enhanced considerably as a result of etching. To investigate the depth of penetration of the anchored metal into the surface of the particles, surface spectra were obtained as a function of OPE times. This data is given in Table VIII and the phosphorus and rhodium spectra as a function of etch time in minutes is shown in Figure 40. The intensity of the rhodium and phosphorus lines increases up to twenty minutes of etching or equivalent to penetration of 160 nm into the surface of the particles. This analysis indicates that rhodium is fairly uniformly distributed into the particles at least 160 nm into the interior.

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