Chemicals used in wet process wafer manufacturing need to be contained in process tanks that can resist etching, corrosion and remain inert. In some applications, a process may require heating, filtration or the regular addition of chemicals. Quartz tanks are made from semiconductor grade flame-polished quartz and are impervious to the acids and bases used in wafer processing. They minimize contamination of wafers from particles and can be supplied in heated and re-circulating models.
Wet bench processing of silicon wafers consists of fabrication steps such as etching and diffusion with cleaning required in between the steps. The wafers are “masked” to etch specific parts of the wafer to confine diffusion to certain target areas. Once each process step is done, the masking material must be cleaned off.
Cleaning the wafers completely without contamination is crucial. When the wafer is not clean and still has contaminants, even a single particle can result in a badly formed structure or conductor. When such malformations are incorporated into the final product, it can result in defective or lower-quality semiconductor components.
Modutek offers specialized quartz tanks that are made from semiconductor grade flame-polished quartz and are impervious to the acids and bases used in wafer processing. Quartz tank controls allow operators to program reproducible process environments and make sure temperatures and chemical concentrations are consistent. Heating, chemical spiking, and filtration are the three important areas for which specialized control systems are useful.
Heating – Modutek’s high-temperature re-circulating baths and constant temperature tanks heat up rapidly with a temperature rise of up to two degrees centigrade per minute. Quick heating helps improve throughput and accurate temperature control helps ensure high-quality results.
Chemical spiking – Periodic spiking restores the chemical concentration of the chemicals to the desired effect. Modutek has developed an innovative “bleed and feed” spiking method for the sulfuric acid and hydrogen peroxide process.
Filtration – Modutek’s quartz tanks can also reduce particle counts and wafer contamination. The quartz re-circulating tank can filter out particles down to 0.2 microns, improving output quality and reducing component failure rates.
The complete article, “How Quartz Tanks Improve Wafer Manufacturing” explains more details. If you have questions and would like to set up a free consultation, contact Modutek at firstname.lastname@example.org or call 866-803-1533.