Semiconductor reactor analysis

Chemical engineers have an obvious role to play in raw material and reactor effluent processing and in process integration and optimal control. They need to apply semiconductor reactor analysis to solve the critical problem... 

NAA is well suited for Si semiconductor impurities analysis. The sensitivity and the bulk mode of analysis make this an important tool for controlling trace impurities during crystal growth or fer monitoring cleanliness of various processing operations for device manufacturing. It is expected that research reactors will ser e as the central analytical facilities for NAA in the industry. Since reactors are already set up to handle radioactive materials and waste, this makes an attractive choice over installing individual facilities in industries. 

Physical vapor deposition (PVD) is used for the deposition of semiconductor, insulator, and metal layers in the fabrication of a variety of electronic devices. Reactors for PVD are characterized by direct line-of-sight transport of molecular species from the gas phase to the desired substrate, where they react to form solid films with the desired properties. A reactor-and-reaction analysis of PVD quantitatively examines the generation of gas-phase species, spatial distribution of species arriving on the substrate, and surface reactions leading to film growth. 

The American consortium NeSSI [23] (New Sampling Sensor Initiative) is a CPAC-sponsored (Center for Process Analytical Chemistry) open initiative formed in 2000 to create a standard for process analysis. The object is to implement modular and smart process analytics. It also aims at the future integration of micro analytical devices and micro structured reactors. The concept is derived from the semiconductor industry and follows the ISA SP76 standard. Companies such as Parker-Hannifin, Kinetics and Swagelok are involved. Further information is also given on the web site [23],... 

Neutron activation analysis is one of a small number of methods capable of multi-elemental analysis of subnanogram quantities of contaminants in semiconductors and other materials. Milligram to gram-sized samples of silicon, quartz, graphite, or organic materials are nearly Ideal for the method. The physics of the processes involved is simple, and qualitative identification of components is an Integral part of the quantitative analysis. Except for the need for access to a nuclear reactor, the equipment required is readily available commercially, and is comparable in cost and complexity to that used in other advanced analytical techniques. 

The method of spark source MS was developed by Dempster in 1935 . During the last two or three decades, this technique was utilized in the trace analysis of impurities in high purity elements, such as semiconductors, superconductors, nuclear reactor components and magnetic, thermoelectric or luminescent materials. There is an urgent necessity for the determination of trace elements in these materials, because they are characterized by the presence or absence of particular elements in the ppm or ppb range. 

---