Semiconductor manufacturing applications

TXRF is frequently used for contamination control and ultrasensitive chemical analysis, in particular in relation to materials used in semiconductor manufacturing [278,279], and metallic impurities on resin surfaces, as in PFA sheets [279,280], TXRF has been used by Simmross et al. [281] for the quantitative determination of cadmium in the four IRMM polyethylene reference materials (VDA-001 to 004). Microsamples (20-100 ig) from each reference material were transferred by hot pressing at 130 °C as 3 xm thin films straight on to quartz glass discs commonly used for TXRF analysis. The results obtained were quite satisfactory (Table 8.50). Other reports of the forensic application to plastic materials by TXRF have appeared [282], including a study of PE films by elemental analysis [283],... 

In the field of microelectronics, there is continuing research in developing new materials to be used in semiconductor fabrication. They must be formed as thin films in a controlled, reproducible and uniform manner to be useful in semiconductor manufacturing applications. Depth profiling by AES is used to assess the properties of such films. The samples are sputtered with an argon ion beam and analysis performed using standard sensitivity factors, and it is possible to demonstrate that such films are uniform throughout a depth of, say, 250 nm. 

The high selectivity of wet etchants for different materials, e.g. Al, Si, SiOz and Si3N4, is indispensable in semiconductor manufacturing today. The combination of photolithographic patterning and anisotropic as well as isotropic etching of silicon led to a multitude of applications in the fabrication of microelectromechanical systems (MEMS). 

The HF tester is a commercial safety tool for sensing whether an unidentified liquid contains HF [2], It shows in an exemplary way how the electrochemical properties of a silicon electrode, namely its I-V curve in HF, can be applied for sensing. The ability to dissolve an anodic oxide layer formed on silicon electrodes in aqueous electrolytes under anodic bias is a unique property of HF. HF is therefore the only electrolyte in which considerable, steady-state anodic currents are observed, as shown schematically in Fig. 3.1. This effect has been exploited to realize a simple but effective safety sensor, which allows us to check within seconds if a liquid contains HF. This is useful for safety applications, because HF constitutes a major health hazard in semiconductor manufacturing, as discussed in Section 1.2. 

Nanotechnology promises to revolutionize a growing set of materials applications ranging from technology sectors such as semiconductor manufacturing, advanced sensors and coatings, to biomedical sectors such as drug delivery and implant... 

The acceptance of chemical mechanical planarization (CMP) as a manufacturable process for state-of-the-art interconnect technology has made it possible to rely on CMP technology for numerous semiconductor manufacturing process applications. These applications include shallow trench isolation (STI), deep trench capacitors, local tungsten interconnects, inter-level-dielectric (ILD) planarization, and copper damascene. In this chapter. 

Focused ion beams can be used to expose resist, to write directly diffusion patterns into semiconductor substrates, and to repair masks. These techniques can potentially simplify semiconductor device production and perhaps reduce cost. Many of the technological challenges with ion beams are similar to those encountered with electron beams, but the development of ion sources and focusing/deflection systems are at a much earlier stage of development so application to manufacturing is several years away. 

Of all the substitutions possible, the use of deionized water in place of tap or softened water has potentially the greatest impact and widest application in the reduction of waste generation. Strongly supported in the literature [6][7], this option has seen widespread use in industries where water quality is seen to be a critical parameter (e.g., semiconductor manufacture). And yet most plating operations use deionized water only to replace evaporation from plating process solutions, if at all. The results of this choice are significant and far-reaching. 

DNQ—novolac resist chemistry has proved to have remarkable flexibility and extendibility. First introduced for printing applications, DNQ—novolac resists have been available since the eady 1960s in formulations intended for electronics applications. At present, most semiconductor manufacturing processes employ this resist chemistry. Careful contemporary research and engineering support the continuing refinement of this family of materials. 

Since the original proof of concept, and a later demonstration of its practical use in semiconductor manufacturing (40), applications and extensions of this concept have proliferated. In the following sections these systems are described in greater detail with emphasis on the resist formulation at a components level (41). 

Application of silanes for promoting resist patterning layer adhesion in semiconductor manufacturing... 

Modifed PTFE can be used in practically all applications, where the conventional polymer is used. In addition to that, new applications are possible because of its improved flow and overall performance. In the chemical process industry, it is used for equipment linings, seals, gaskets, and other parts, where its improved resistance to creep is an asset. In semiconductor manufacturing, modified PTFE is used in fluid handling components and in wafer processing components. Typical applications in electrical and electronic industries are connectors and capacitor films. Other applications are in unlubricated bearings, laboratory equipment, seal rings for hydraulic systems, and antistick components.103... 

The pharmaceutical industry lead the way in adoption of CEDI for the production of ultrapure water. Since the early 1990 s, the power industry has been employing CEDI as a polisher for RO effluent for steam generation. Other industries currently using CEDI include general industry for boiler make-up or high-purity process applications, including semiconductor manufacture. Commercially-available industrial CEDI modules range in size from less than 1 gpm to 80 gpm. 

Over the last decade, printed electronics has received substantial attention as a potential application of inkjet technology. Conceptually, the goal is to use printing technology as a replacement for conventional photolithography-based semiconductor manufacturing. This is expected to result in a substantial cost reduction for the realization of simple semiconductor systems on cheap, flexible substrates such as plastic, steel foils, etc. 

Perfluoroelastomers, such as Kalrez, are particularly suited for extreme service conditions. They are resistant to more than 1500 chemical substances, including ethers, ketones, esters, aromatic and chlorinated solvents, oxidizers, oils, fuels, acids, and alkali, and are capable of service at temperatures up to 316°C (600°F) [76]. Because of the retention of resilience, low compression set, and good creep resistance, they perform extremely well as static or dynamic seals under conditions where other materials such as metals, FKM, PTFE, and other elastomers fail. Parts from FFKM have very low outgassing characteristics and can be made from formulations that comply with FDA regulations [77]. Primary areas of application of perfluoroelastomers are paint and coating operations, oil and gas recovery, semiconductor manufacture, phar-... 

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