Plasma Generators Information
Plasma generators produce the needed radio frequency (RF) power to create and maintain plasma in plasma chambers and similar devices. The plasma generated can be used in numerous applications including integrated circuit (IC) or industrial manufacturing for film deposition, surface cleaning, and surface modification.
Production of plasma is accomplished by adding enough energy to a gas to free electrons from their atoms or molecules and to allow both the resulting ions and electrons to exist together. One way to generate this ionized gas, or plasma, is by introducing a gas into a space between two parallel electrodes. One electrode is grounded, while the other is energized by power from an RF generator. The capacitive or inductive coupling between the electrodes excites the gas, creating plasma. A common RF power frequency used to produce plasma is 13.56 MHz. Other frequencies include 40 kHz and 2.45 GHz.
There are many different processes that make use of generated plasma.
- Plasma-enhanced chemical vapor deposition (PECVD) is used in semiconductor manufacturing to deposit films conformally and onto wafers containing metal layers or other structures sensitive to temperature.
- High density plasma chemical vapor deposition (HDPCVD) is a special variant of PECVD that produces a higher plasma density through the use of inductively coupled electrodes, allowing deposition of higher quality films at lower temperatures.
- Chemical vapor deposition (CVD) is often used to deposit dielectric films such as silicon dioxide (SiO2) and silicon nitride (Si3N4) in the production of electronic devices. The insulating films can isolate conductive layers, passivate surfaces, and encapsulate components to protect devices from corrosion.
- Physical vapor deposition (PVD) involves generating a vapor to deposit onto an object by a physical process such as introducing a powder into a plasma flame.
- Plasma-enhanced atomic layer deposition (PEALD) can deposit materials with high precision to create ultra-thin, uniform films at relatively low temperatures.
Plasma generators are used in a wide variety of applications. One of the prime applications is semiconductor fabrication for the production of integrated circuits or chips. Plasma generators are also used to create plasma for:
- Cleaning of materials such as metals, plastics, glasses, and ceramics including removal of organic layers and reduction of oxides.
- Activating material surfaces to create surface functional groups and radical sites in intrinsically inert surfaces that will react more readily.
- Etching of surfaces to create a systematically structured surface area by creating a phase change in the etched material and removing it.
- Plasma coating to protect surfaces or change their properties such as making a hydrophobic material wettable or adding a diffusion barrier to a porous material.
Plasma generators can be used in the manufacture of:
- Integrated circuits
- Solar cells
- Fuel cells
- Flat panel displays
- Data storage devices
- Power electronics
- Medical devices
- Optical devices
Key specifications to consider when selecting a plasma generator include operating frequency and output power.