Patterning, electronic devices

The most extensive application of a-diazocarbonyl compounds is in the lithographic production of integrated circuits used by the computer industry. The majority of photoresist materials involved in this process are a-diazoketone derivatives. 2 Upon photolysis, these compounds form ketenes that subsequently react with water to produce carboxyhc acids. The difference in carboxylic acid and diazoketone solubility is then utilized to pattern electronic devices. 

Element mapping with non-resonant laser- SNM S can be used to investigate the structure of electronic devices and to locate defects and microcontaminants [3.114]. Typical SNMS maps for a GaAs test pattern are shown in Fig. 3.43. In the subscript of each map the maximum number of counts obtained in one pixel is given. The images were acquired by use of a 25-keV Ga" liquid metal ion source with a spot size of approximately 150-200 nm. For the given images only 1.5 % of a monolayer was consumed -"static SNMS". 

We have designed, manufactured and tested a prototype that may be applied in thermal control of electronic devices. It was fabricated from a silicon substrate and a Pyrex cover, serving as both an insulator and a window through which flow patterns and boiling phenomena could be observed. A number of parallel triangular micro-channels were etched in the substrate. The heat transferred from the device was simulated by different types of electrical heaters that provided uniform and non-uniform heat fluxes, defined here respectively as constant and non-constant values... 

The developed theory of two-phase laminar flow with a distinct interface which is based on a one-dimensional approximation, takes into account the major features of the process the inertia, gravity, surface tension and friction forces and leads to the physically realistic pattern of a laminar flow in a heated micro-channel. This allows one to use the present theory to study the regimes of flow as well as optimizing a cooling system of electronic devices with high power densities. 

The influence of metal species like copper has been investigated on the product pattern and yield of PBDD/F (Fig. 7) (ref. 11). This study is relevant to accidental fires of polymeric materials of electronic devices which are associated with various metals like copper. As a result of the presence of the metal species substantial amounts of both PBDF and PBDD are formed. 

Silicates comprise more than 95% by weight of the earth s crust and mantle, and are widely used in glasses, ceramics, sieves, catalysts, and electronic devices. Crystals of silicates are often hard, and may show considerable extinction in their diffraction pattern, which means not only that small samples must be used, but also that ambient temperatures may be adequate for charge density studies.2... 

Thin films (qv) of vitreous silica have been used extensively in semiconductor technology. These serve as insulating layers between conductor stripes and a semiconductor surface in integrated circuits, and as a surface passivation material in planar diodes, transistors, and injection lasers. They are also used for diffusion masking, as etchant surfaces, and for encapsulation and protection of completed electronic devices. Thin films serve an important function in multilayer conductor insulation technology where a variety of conducting paths are deposited in overlay patterns and insulating layers are required for separation. 

Today the frontier of the fabrication of electronic devices has moved from the micrometer scale down to tens of nanometers scale. Scaled-down conventional devices such as field-effect transistors and devices based on quantum effects are two most prominent examples of the electronic miniaturisation [20, 23,430]. The major challenges in preparation of such devices are (i) growing the substrate materials and (ii) patterning the substrates. Whereas the former rely on self-organisation of the surface structure, the substrate patterning on the nanoscale requires special tools. 

Towards fabrication of SWNT-based molecular electronic devices, two methods have been used to assemble the 03-SWNTs on functionalized SAMs of OPEs, as shown in Figure 5.10. The first, termed chemical assembly , is based on a condensation reaction between the carboxylic acid functionalities of O3-SWNTs and the amine functionalities of SAMs to form amides. The results show that O3 -SWNTs coat the amino-terminated SAM with a high degree of surface coverage. The second method is based on physical adsorption via layer-by-layer (LBL) deposition with bridging of metal cations, i.e., Fe3+ on carboxylate terminated SAMs or Cu2+ on thiol-terminated SAMs. The oxidatively shortened 03 -SWNTs are shown to be perpendicular to the surface with random adsorption of longer tubes. The patterned nanotube assemblies may be useful in hybridized electronic devices, where device functions can be modified by the orientation and stacking of SWNTs, and the properties of the SAM. 

Kim C, Shtein M and Forrest S R, Nanolithography based on patterned metal transfer and its application to organic electronic devices , Appl Phys Lett, 2002 80 4051-4053. 

The challenge for jet-print patterned TFT devices is achieving sufficient precision and reliability to fabricate electronic circuits having the desired feature size and performance. This section discusses the feasibility of using phase-change etch masks patterned by jet printing, in place of conventional photolithography. 

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