Optical inspection for impurities is one of many critical steps in the wafer manufacturing processes that have been developed by chemical engineers. Courtesy Sitronics Telecom Solutions.
The purity requirements of today’s semiconductor facilities are even more stringent than those used in the food-processing industry. Unwanted impurities—dissolved and particulate contaminants and trace metals—can easily ruin individual wafers and severely cut back on a manufacturing facility’s output.
Keeping impurities at bay
Even the tiniest of impurities found in process chemicals and gases can create a huge problem. Unless various engineered solutions are used to remove them, such impurities may be found in the chemicals employed during the manufacturing process. Chemical engineers are constantly pursuing advanced technologies and procedures to ensure that critical process ingredients maintain low levels of contaminants—so low, in fact, that they are measured in parts per million to parts per trillion.
To meet these standards, chemical engineers must specify the appropriate combination of purification techniques. These scientists must also select construction materials for all vessels, piping, valves, pumps, tanks, and other components in order to minimize the introduction of dissolved impurities. To ensure that acceptable purity levels are maintained, various measurements are made throughout the process.
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