Plasma contains positively charged ions and negatively charged electrons, which can be controlled by electric or magnetic fields. In the semiconductor industry, plasma can be processed early on in two different ways: sputtering and photoresist striping.
In this process, plasma is created using inert gas atoms, such as argon. Argon, very commonly used in sputtering, or another form of inert gas is then pushed rapidly toward a specified target surface. When the gas atoms hit the surface, atoms sitting on the target surface are knocked off. Due to the low pressure system, these released atoms are then able to travel straight to the substrate.
Photoresist Striping and Etching
With this process, oxygen is the most used gas. The oxygen atoms are excited in the plasma, making the plasma highly reactive with organic materials. The photoresist residue resulting from photolithography processing is made up mostly of organic chemicals, meaning the oxygen atoms react strongly with this residue to create carbon dioxide.
In the semiconductor industry today, plasma is largely used in the plasma dry etching process. Semiconductor devices are employed to work through the following plasma dry etching steps:
- Reactive species are generated in the plasma
- Through a diffusion process, the species are released to the surface for etching
- The species are then adhered to the surface
- Chemical reactions occur between the reactive species and the material surface
- The byproduct formed by the chemical reaction is then desorbed from the surface
- The desorbed byproduct is diffused into the gas
Plasma dry etching has taken over the wet etching processes that were common a little over a few decades ago. In the semiconductor industry, plasma dry etching is required for the small attributes of semiconductor devices.
At Shin-Etsu MicroSi in Phoenix, we specialize in developing and manufacturing materials for use in the semiconductor industry. We have only the highest quality products available for processing plasma to create finished semiconductor devices. For more information, please call Shin-Etsu MicroSi at (480) 893-8898 or contact us online.