Applications > What is plasma?
What is Plasma?
Plasma, the fourth state of matter, is a partially ionized gas mixture consisting of ions, free radicals, neutral byproducts, and photons. Plasma is an electrically neutral mixture of physically and chemically active gas phase species capable of surface modification. The surface modification is the result of the interaction between the gas phase active species and a solid surface. The active species within the plasma are cable of both physical work via ion assisted sputtering and chemical work through radical or byproduct chemical reaction. As a result, plasma can perform numerous surface modification processes including surface activation, contamination removal, cross linking, etch by chemical reaction, and physical bombardment.
There are two key mechanisms in plasma processing: a physical mechanism performed by ions and a chemical mechanism performed by free radicals and byproducts. Physical plasma is a result of the charged ionic species gaining sufficient kinetic energy from the applied electric field to perform sputtering. Through energy transfer, partial molecules partial molecules and atoms are sputtered from the surface, resulting in contaminant removal from the substrate surface. Physical bombardment also changes the topography of the surface, increases the surface roughness at molecular level, and can aid in interface adhesion. Chemical plasma relies on the chemically active free radicals and byproducts generated in the plasma to diffuse to the sample surface. These free radicals and byproducts decrease the activation energy in a chemical reaction, resulting in material removal. The volatile chemical reaction byproducts are removed from the sample surface and the process chamber by the vacuum system. Isolation of a particular plasma mechanism is determined by the plasma mode, where the mechanism selection is based upon the packaging application.
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Semiconductor
The Semiconductor Business Group focuses on plasma processes for advanced semiconductor packaging and assembly (ASPA), wafer level packaging (WLP), microelectromechanical systems (MEMS), data storage devices such as thin film read-write heads (TFH) for hard disk drives, and images sensors. More>>>
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The Medical Device Business Group is engaged in providing enhanced product performance, more reliable devices and lower cost processes to companies who manufacture leading edge medical devices including cardiac rhythm management products, catheters, stents, ocular devices, and filter media.
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Printed circuit board manufacturers work with our PCB Business Group due to the implementation of new materials technology, and smaller geometries in HDI, flex, and rigid flex applications. More>>>