Applications in the Semiconductor Industry

An example where all four areas are utilized in combination with production processes is found in ozone applications in the semiconductor industry (Section B 6.1). Part of ozone s effectiveness in these four areas is derived from its production of OH-radicals. Combined processes, i. e. advanced oxidation processes, represent alternative techniques for catalyzing the production of these radicals and expands the range of compounds treatable with ozone (Section B 6.2). 

An oxide layer is produced on the surface of the silicium wafer (Si02). This layer of silicium dioxide is an isolating layer on the surface, it is usually grown in an atmosphere containing oxygen, water vapor or other oxidants (02, 03, H202). 

In the photolithographic process, the geometrical pattern that produces the desired electrical behavior is transferred to the surface of the wafer. 

In this process step an etchant (gas or liquid) removes the Si02 where it is not protected by the photoresist. Ions are implanted into the unprotected silicium. With the implantation of ions the structure of the surface will be changed. 

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Gallium and indium phosphides, arsenides and anti-monides have important applications in the semiconductor industry (see Sections 5.9 and 27.6 Boxes 13.3 and 18.4). They are used as transistor materials and in light-emitting diodes (LEDs) in, for example, pocket calculators the colour of the light emitted depends on the band gap. Figure 12.3 shows that, in 2001, the US used 37% of the gallium produced worldwide. Almost all of this was used in the form of GaAs 34% went into LEDs, laser diodes, photodetectors and solar cells, while 65% found application... 

Of the group 13 metals, only Al reacts directly with N2 (at 1020 K) to form a nitride AIN has a wurtzite-type structure and is hydrolysed to NH3 by hot dilute alkali. Gallium and indium nitrides also crystallize with the wurtzite structure, and are more reactive than their B or Al counterparts. The importance of the group 13 metal nitrides, and of the related MP, MAs and MSb (M = Al, Ga, In) compounds, lies in their applications in the semiconductor industry (see also Section 19.4). 

Infrared spectroscopy is particularly useful in the study of adsorption and decomposition of molecules on a Si surface, an important application in the semiconductor industry, which has a variety of processes that involve the reaction of gas-phase molecules with a Si surface. There is a plethora of measurement techniques in IR spectroscopy that have good surface sensitivity. The chemical information available, including identification and determination of concentrations of species plus structural information, can be obtained with very high resolution and yet with no undesirable physical or chemical changes in the material of interest caused by the measurement [117]. 

In applications in the semiconductor industry, polymer structures are required on length scales down to individual molecules. A bottom-up approach is better than a top-down approach in order to achieve this. A lateral resolution less than 100 nm can be created by surface instabilities and pattern formation in polymer films. Steiner [6] discussed demixing of polymer blends and pattern formation by capillary instabilities for nanostructure formation. 

The properties and processibility of PFA have allowed for the development of a wide variety of components that are used in critical wet chemical applications in the semiconductor industry including high purity bulk chemical systems, wet etching systems, stripping systems, cleaning systems, chemical mechanical planarization (CMP) system components, analytical equipment, and high purity chemical manufacturing. 

A number of workers noticed insufficient adhesion of the deposit to the substrate and insufficient long-term stability under operating conditions as defects of SD. It was pointed out, on the other hand, that the method, unlike in its applications in the semiconductor industry, is not required to yield continuous films when used to produce catalytic deposits deposition in the form of individual, catalytically active surface segments will be sufficient. 

In semiconductor manufacturing, the goal is to control quahties such as film thickness or electrical properties that are difficult, if not impossible, to measure in real-time in the process environment. Most semiconductor products must be transferred from the processing chamber to a metrology tool (measuring device) before an accurate measurement of the controlled variable can be taken. The scope of run-to-run control applications in the semiconductor industry is significant. 

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