Wafer processing, discussion

The process discussed in this section was applied both to the metallized wafer to be measured and to the preparation of the thermistor used in the discussed experiments. 

What is accomplished by adhesion promotion treatments in IC manufacturing should actually be referred to as wafer substrate preparation, and not adhesion. Adhesion in the structural sense, as experienced in airplane composite material parts attachment, is not accomplished by silane wafer processing treatments except for the PI applications discussed early in this paper. The term adhesion, as it is used here, refers to a more practical definition—that is, resist image adhesion. Nevertheless, this type of adhesion is essential to the huge international semiconductor business, and the early silane work of Plueddemann and others was essential to early wafer adhesion process development. 

The deposition processes discussed so far typically operate such that all the material required for the growing film comes from the overlying gas or liquid phase. Other deposition reactions involve reaction (and therefore consumption) of the underlying substrate itself. Examples of such deposition processes include thermal oxidation, nitridation, or silicidation of silicon, which can be accomplished by exposing a silicon wafer at high temperature to oxygen, ammonia, or titanium tetrachloride, respectively, to form silicon dioxide, silicon nitride, or titanium disilicide. Solid-phase diffusion and reaction processes are involved in each case. 

The manufacture of waferboard and OSB has many of the same process steps as particleboard, but adapted to the special needs of producing an exterior quaHty panel with large wafers or strands. This discussion focuses on OSB, because waferboard has been almost entirely replaced by OSB and most of the early waferboard mills have now been converted to production of OSB. The OSB process is outlined in Figure 8. 

The starting material for the sensor fabrication are fully processed wafers of a 2-poly 2-metal 0.8 pm industrial CMOS process provided by austriamfcrosystems (Unterprem-statten, Austria). In the following, the main post-CMOS processing steps (schematically summarized in Fig. 4.2) are discussed. 

Wright of Advanced Micro Devices discusses the use of Raman microspectroscopy to measure the integrity of a film on semiconductor wafers during manufacture in US patent 6,509,201 and combined the results with other data for feed-forward process control [181]. Yield is improved by providing a tailored repair for each part. Hitachi has filed a Japanese patent application disclosing the use of Raman spectroscopy to determine the strain in silicon semiconductor substrates to aid manufacturing [182]. Raman spectroscopy has a well established place in the semiconductor industry for this and other applications [183]. 

To enable reflectometry to provide accurate, reproducible, and efficient measurements, several factors must be considered. Choice of the substrate material, substrate modeling, number of measurements per wafer, choice of the measurement patterns, and the setup of the pattern recognition program are all critical to the measurement process, as discussed in the following. 

In this paper, we shall discuss the processing steps used in a typical PI coated wafer. The chemistry that is relevant to processing and film properties will also be discussed with special emphasis on adhesion, cure cycle, and thermostability. 

In this paper, the application of microelectronic processing technology to the fabrication of SnOx and PdAu/SnOx microsensors on silicon wafers is described, sensor responses to various gases in air are presented, and the possible sensing mechanisms are briefly discussed. 

Wright of Advanced Micro Devices, Inc. discusses the use of Raman spectroscopy to measure the integrity of a film on semiconductor wafers during manufacture in US patent 6,50 9,201.87 The Raman measurements are made during the manufacturing process and can be considered an on-line system. Unlike many process Raman installations, this one is based on micro-Raman, where a microscope is used to focus the laser beam to a spot only a few micrometers in diameter. The Raman data is combined with other measurements, such as scatterometry, to calculate a stress level and compare it to... 

In this section we will review the various types of CVD reactors scientists and engineers have used for the development of thermal CVD processes. This will be distinct from the commercial reactors used for production which will be covered in a later chapter. A similar review of reactors for development of plasma-enhanced CVD processes will be made at the end of the next chapter. We will cover the so-called cold wall systems for either single or multiple wafers first, followed by a discussion of continuous belt systems. Finally, we will review the hot wall reactor approach. 

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