Preserving purity during silicon chip manufacturing
The microelectronic devices, or silicon chips, that are embedded into so many of our everyday devices require ever more precise production steps as their capability increases. To perform at the highest level, they need to be produced from high purity materials with predictable electronic properties.
Furthermore, all manufacturing steps must preserve the purity of the materials by preventing contamination with substances that are usually considered harmless such as oxygen, water vapor, copper and iron.
Many of the manufacturing steps involved in making a silicon chip take place in vacuum systems whereby the composition of the environment around the device can be controlled. In addition, the vacuum system is expected not only to prevent any contamination of the incoming gases but also to avoid contamination of the devices with microscopic dust particles or solid contaminants.
Abatement to limit, reduce and control undesirable by-products
In general, during the production of silicon chips, undesirable by-products are created which companies, stakeholders and national and international organizations wish to limit, reduce and control. The process gases and process by-products are invariably toxic, corrosive, flammable, explosive or global warming in nature, and their uncontrolled release to the atmosphere after the manufacturing process would be considered irresponsible and hazardous.
In addition, many process by-products have a tendency to condense in pipework downstream of the vacuum pump once they have been compressed to atmospheric pressure. This can fill the exhaust pipes that transit the silicon chip factory basement, or “subfab,” with solid or liquid materials that may also be toxic, corrosive, flammable or explosive.
These materials present a particular safety risk both to the fab in general and also to the service personnel who have to clean out the exhaust pipes. As a consequence, abatement or neutralization of the process effluent close to its point of production has become the widespread norm in today’s silicon chip manufacturing facilities.
The abatement process explained
The abatement process employed by Edwards in its abatement products includes two key steps. First there is the conversion of the various unused process gases and process by-products into a form in which they can be scrubbed out of the exhaust stream by a water scrubber, and next there is the water scrubbing step itself. In an Edwards point-of-use abatement system, these steps are integrated into a single unit along with a controller to coordinate its operation with the process tool.
By virtue of the comprehensive range of abatement products it offers, the Atlas Copco Group is in a unique position to enable customers to address both their operational reliability needs and their corporate and social responsibility commitments by providing efficient and cost-effective gas abatement systems.
