N-layer

The very considerable success of the BET equation stimulated various investigators to consider modifications of it that would correct certain approximations and give a better fit to type II isotherms. Thus if it is assumed that multilayer formation is limited to n layers, perhaps because of the opposing walls of a capillary being involved, one... 

Adsorption isotherms in the micropore region may start off looking like one of the high BET c-value curves of Fig. XVII-10, but will then level off much like a Langmuir isotherm (Fig. XVII-3) as the pores fill and the surface area available for further adsorption greatly diminishes. The BET-type equation for adsorption limited to n layers (Eq. XVII-65) will sometimes fit this type of behavior. Currently, however, more use is made of the Dubinin-Raduschkevich or DR equation. Tliis is Eq. XVII-75, but now put in the form... 

Three such methods have been proposed by Morokuma and coworkers. The integrated MO + MM (IMOMM) method combines an orbital-based technique with an MM technique. The integrated MO + MO method (IMOMO) integrates two different orbital-based techniques. The our own n-layered integrated MO and MM method (ONIOM) allows for three or more different techniques to be used in successive layers. The acronym ONIOM is often used to refer to all three of these methods since it is a generalization of the technique. 

Step 1. Starting with a lightly doped n-ty e substrate, a thin blanket layer of Si02 (the pad oxide) is formed, and a blanket deposition of a thick protecting Si N layer follows. 

Fig. 9. Fabrication sequence for an oxide-isolated -weU CMOS process, where is boron and X is arsenic. See text, (a) Formation of blanket pod oxide and Si N layer resist patterning (mask 1) ion implantation of channel stoppers (chanstop) (steps 1—3). (b) Growth of isolation field oxide removal of resist, Si N, and pod oxide growth of thin (<200 nm) Si02 gate oxide layer (steps 4—6). (c) Deposition and patterning of polysihcon gate formation of -source and drain (steps 7,8). (d) Deposition of thick Si02 blanket layer etch to form contact windows down to source, drain, and gate (step 9). (e) Metallisation of contact windows with W blanket deposition of Al patterning of metal (steps 10,11). The deposition of intermetal dielectric or final...

Fig. 4.7. A semiconductor detector operated as a pin diode with a reverse voltage or bias. An incident X-ray photon ultimately produces a series of electron-hole pairs. They are "swept out" by the bias field of-500 V- electrons in the direction ofthe n-layer holes in the direction ofthe p-layer. Thus, a small charge pulse is produced after [4.21],...

Similarly, is a moment gemnit width as shown In Figure 4-7. However, Nx, etc., and etc T 6ereferred to as forces and moments with the stipulation of per unit width being dropped for convenience. The entire collection of force and moment resultants for an N-layered laminate is depicted in Figures 4-6 and 4-7 and is defined as... 

Flotz, n. layer, stratum, bed, seam, -erz, n. ore in beds, -gestein, n. stratified rock, -kalk,... 

For the N-layer model in particulates, which is an improvement of the three-sphere model, it has been shown5), by taking into consideration the boundary conditions between phases, that ... 

A series of models were introduced in this study, which take care of the existence of this boundary layer. The first model, the so-called three-layer, or N-layer model, introduces the mesophase layer as an extra pseudophase, and calculates the thickness of this layer in particulates and fiber composites by applying the self-consistent technique and the boundary- and equilibrium-conditions between phases, when the respective representative volume element of the composite is submitted to a thermal potential, concretized by an increase AT of the temperature of the model. 

The Fe-N /Ti-N nano-multilayers were prepared by using the magnetron-sputtering technique [34]. Si (111) wafers are used as the substrate. The multilayers have a total thickness of about 500 nm with alternately Fe-N and Ti-N layers (shown in Fig. 38). The Fe-N layer was the outermost layer and the Ti-N layer was the iimermost layer. The thickness of each layer was strictly controlled by the sputtering time. Table 4 shows the thickness of each layer of the samples. Because the multilayer sample was supposed to be used as the magnetic write head, the thickness of the nonferromagnetic Ti-N layer was not changed. 

Fig. 46—Average friction coefficient (from the 15th second to the 35th second) of the muitiiayers versus thickness of Fe-N layers. The average friction coefficient of Fe-N, Ti-N film and Si (111) wafer under the same condition is aiso shown in this figure. Load, 250 N. (a) Fe-N(40 nm)/Ti-N(2 nm) (b) Fe-N film, 450 nm (c) Ti-N fiim, 450 nm (d) Si(111) wafer.

Fig. 48—Average lateral force (from the 15th second to the 35th second) of the multilayers versus thickness of Fe-N layers. Load,...

Fig. 49—Depth of scratching scar versus thickness of Fe-N layer, (1-250 yiiN 2-1,250 /itN).

Figure 42 shows the dependence of average hardness of Fe-N(450 nm) and Ti-N(450 nm) single layer as well as Si (111) wafer on applied normal force. The hardness of Si (111) wafer almost remeains constant, but under current experimental condition, the hardness of both the Fe-N and Ti-N layer increases with the normal force. This is probably because the thick layers are not homogeneous. The Fe-N layer has the lowest hardness for all the applied normal forces. 

Figure 43 shows the hardness and reduced modulus of Fe-N/Ti-N multilayers versus the thickness of the Fe-N layer. It is found that the hardness of the multilayers decreases with the thickness of the Fe-N layer, but increases with the applied normal force. Under higher normal force, the hardness does not change much if the thickness of the Fe-N layer is thicker than 20 nm. The reduced modulus of the multilayers with different Fe-N layer thickness is always within the range of 170-190 GPa. There is no obvious relationship between the reduced modulus and the thickness of the Fe-N layer. 

Figure 47 shows the typical microscratch scars of a part of the samples under different normal forces. The difference can be found from the scar under 250 /rN. Only a shallow scratch scar is visible on the surface of Fe-N (5 nm)/Ti-N (2 nm) (Fig. 46), but the scars are deeper for other samples except the single crystal silicon wafer (Fig. 47). If the normal force was over 250 /rN, the diamond tip penetrated into and plowed the sample surface. Figure 48 shows the relationship between the lateral force and the thickness of the Fe-N layer under 1,250 /rN. It is found that the lateral force increases with the thickness of the Fe-N layer. For comparison, the lateral force of Fe-N, Ti-N, him and Si (111) wafer under...

The friction coefficient is lower for the multilayers than for the Fe-N single layer. This is because the multilayers have a smaller grain size than the Fe-N single layer [37]. For multilayers, the forces applied on the tip are complex during the scratching process. The reason why the lateral force increases with the thickness of the Fe-N layer is mainly because the scratch scar increases with the thickness of the Fe-N layer (Fig. 49). It is the same reason why the lateral force of the Fe-N single layer is larger than that of Fe-N multilayers. 

The friction coefficient of the Fe-N/Ti-N multilayers increases with the thickness of the Fe-N layer if the thickness of the Fe-N layer is more than 10 nm. It is lower than that of Fe-N film. 

Additive schemes. The general formulations and statements. Considerable effort is devoted to a discussion of additive schemes after introducing the notion of summarized approximation. With this aim, we recall the notion of the n-layer difference scheme as a difference equation with respect to t of order n — 1 with operator coefficients ... 

By the n-layer composite scheme of period m (of order m) we generally mean a system of differential equatioins with operator coefficients... 

Several particular cases will be given special investigation. For m = 1 the composite scheme (41) falls within the category of standard n-layer schemes. For n = 2 the describing scheme is termed a two-layer composite scheme of period m... 

The number and sharpness of fluid layers depend sensitively on the porewldth as Is Illustrated by the theoretical results (which agree qualitatively with simulations) plotted In Figure 2. As porewldth Is Increased from say h = a, there appear one, two, three, etc. density peaks. A transition from N to N -h 1 peaks occurs as the porewldth varies from a value at which N layers are favored to a value at which N -f 1 are favored. A... 

Several differences from that of an integrated circuit can be noted. First of all, two (2) electrlced contacts must be established across the bulk of the silicon wafer. When light strikes the surface of the solcU cell, its absorption within the silicon bulk releases electrons which are collected as a current. Also shown is the p-n junction. However, the actual silicon disc is only about 350 pm. in thickness. Diffusion processes are used, as a matter of practicality, to form both the p-layer and the n-layer. Thus, the... 

Once the silicon disc is cleaned, the first step is diffuse ions into either side of the silieon disc to first form either the p-layer or the n-layer. Some manufacturers like to have the n-layer closer to the light source, as shown in the above diagram, while others prefer the opposite. At any rate, ions like and are generally used to form the active electrical layers. A number of differing processes have been developed to do this, the exact nature of which depending upon the speeific manufacturer of solar cells. Sputtering, vapor-phase and evaporation are used. The most common process uses a volatile boron or phosphorous compound to contact the surface. 

The intrinsic material fabricated at the frequencies reported above was incorporated in p -i-n solar cells [493]. The p- and n-layer were prepared by the conventional 13.56-MHz discharge. The device quality films indeed yield good solar cells, of 10% efficiency, as is shown in Figure 60. This cell is manufactured with a 500-nm-thick t -layer made at 65 MHz with a power density of 42 mW/cm , resulting in excellent properties. The deposition rate still is 2-3 times higher than... 

The p and n layers provide the built-in potential but do not contribute to the collection of carriers. Therefore these layers need to be only as thick as the de-... 

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