Electron Cyclotron Resonance Chemical Vapour Deposition (ECR-CVD)
ECR-CVD by ASTeX
The two electron cyclotron resonance chemical vapour deposition systems (ECR-CVD) by Applied Science and Technology (ASTeX) consists of the following main components: 2.45 GHz microwave generator, two magnets providing a strong mirror magnetic field, water-cooled ECR excitation chamber, low pressure processing chamber, substrate holder, and substrate heater.
The ECR source generates a uniformly distributed, high density plasma with a very high ion content. It does so by exciting the process gas with the 2.45 GHz microwave energy in the strong magnetic field within the high-vacuum ECR excitation chamber. In regions where the field strength is approximately 875 Gauss, electron cyclotron resonance occurs. This causes the free electrons in the plasma to efficiently absorb the microwave energy. The electrons lose this kinetic energy to neutral species through collisions producing more ions and electrons. In this way, a plasma is produced with an electron density greater than 1012e/cm3 and ion current density greater than 100mA/cm2. The higher ion density leads to a greater efficiency in the breaking of the chemical bonds of the reactant gas.
In our institute the ECR-CVD system is used to deposit various kinds of films, such as diamond, metal, oxide, carbon-fibres or -tubes, DLC, and so on. The high ion density and electron temperature in the ECR generated plasma allows for high throughput at relatively low deposition temperatures and pressures (10-4-10-2 mbar) - thus minimizing damage and contamination of the substrate and resulting in lower defect density and interfacial damage in the films. It is also compatible with a wide range of inert and reactive process gasses.