Plasma treatment industry
How does plasma etching work?
Plasma treatments are used in a number of industries for preparing surfaces. Different materials like glass, plastic, ceramics, metals, and more are then ready for further processes, such as printing or coatings.
Two of the most common uses of plasma, however, are for etching and cleaning.
What is plasma?
Plasma is a high-energy discharge of electrons, usually in combination with a gas such as oxygen, argon, or hydrogen. Ordinary air is also used, or combinations of gasses.
The atoms of the plasma gas become excited to highly reactive ions. As the atoms expend their energy and return to a normal state, they release a photon, or particle of light, accounting for the bright glow characteristic of plasma work.
Different gasses will produce different colored light. Oxygen plasma, for example, creates a light blue light.
The impact on the subject material occurs because of the collision between the highly charged plasma and the atoms of the target substance.
This can change the physical and chemical properties of the substance to various depths, depending on the desired effect and the nature of the plasma gas used, referred to as its series.
The series is the unique conditions created by the environment of reactive ions, neutral particles, and negative electrons. The effect that’s produced on the target can be permanent or temporary.
This involves precise application of the plasma in order to create specific paths. This etching can be very fine and is used in many technical operations, such as the manufacture of electrical components for use in medical devices, automobiles, and other technical needs.
Plasma etching is usually done in rapid pulses for consistency and exact control. This results in layouts where the chemical composition of the target is altered at or just below the surface, giving it different properties along the etched path. It can also change the contact angle with the surface along these lines.
Several factors can be involved for a proper plasma etch of different materials, including the electron source, species, pressure, temperature, or additional conditions such as vacuums.
Volatile by-products are known and planned to be either removed through adsorption in the gas or can actually help the etching process. If these volatile products are not used or resorbed, they can form a thin layer on the material.
While other techniques like microwave etching can be used, hydrogen plasma is the norm for manufacturing integrated circuits. It cuts a channel into the silicon wafer while at the same time removing certain contaminants like natural oxides for a more stable, efficient energy flow within the chip.
This uses many of the same techniques, but instead of etching, it’s used to remove impurities over a wide area. Cleaning is often crucial for certain chemical or biological processes to take place correctly, or creating ideal surfaces for gluing or bonding effectively.
Use of oxygen plasma, for instance, results in a high VUV energy that’s effective in breaking down organic compounds for a sterile surface.
The only byproducts are usually water, carbon dioxide, and carbon monoxide, along with vaporized hydrocarbons, that can be extracted from the cleaning chamber for a very clean and safe surface.
With oxidizable materials like copper or silver, inert gasses like helium or argon are used to prevent rust or corrosion from forming on the fresh surface.
Plasma cleaning can also act as a sort of sandblasting process to clean these oxides from metals, along with any biological substances. Softer substances like rubber, polymers, and fibers can also benefit from plasma cleaning when desired.
Plasma cleaning is a cost-effective and efficient way to create an immaculate surface on manufactured components.
Benefits of Plasma
Plasma is a more environmentally safe method than the use of strong industrial chemicals. Many processes also require an extremely high temperature whereas plasma processing can work at room temperatures for many purposes.
This also uses less energy and reduces overhead. In addition, a plasma etch or cleaning are more thorough and uniform than other methods.
This allows companies to obtain the most satisfactory results with the least effort.