Plasma-enhanced chemical vapour deposition
In plasma-enhanced chemical vapour deposition (PECVD), the chemical reaction is supported by plasma. This reduces the temperature load of the substrate because process temperatures between 200 and 500°C are sufficient to achieve the final films due to plasma assistance.
The plasma can be ignited in the immediate vicinity of the substrate (direct plasma method). For sensitive substrates, such as semiconductor wafers, there is a danger of damage due to radiation and ion bombardment.
In the remote plasma method, on the other hand, the plasma is spatially separated from the substrate. The barrier protects the substrate; it also enables the selective excitation of individual components of the process gas mixture. However, the process needs to be carefully designed so that the chemical reaction does not take place until the activated elementary particles actually reach the substrate surface.
There is a great variety of applications for the "low-temperature CVD" process and FHR has many years of experience in this field. This makes PECVD an interesting alternative for coating substrates that cannot withstand high temperatures. For example, this method allows for the application of thin functional layers onto plastic films.
This coating process is also frequently used in the semiconductor industry because doping profiles can be destroyed by diffusion processes at high temperatures. In addition, many compounds required in microelectronics, such as amorphous silicon, silicon nitride or silicon oxide, can be deposited using PECVD.
The PECVD systems at FHR are specifically set up for each customer and specially adjusted to their respective process requirements. We also frequently use PECVD compartments to enhance the technological range of sputtering system. Let FHR convince you with our competitive prices and excellent system quality.
Chemical vapour deposition
Chemical vapour deposition (CVD) is a proven coating method frequently used in thin film technology. In this method, a thin layer of a solid material is deposited on the heated surface of a substrate by a chemical reaction in the gas phase. FHR offers special solutions for CVD coating of wires and fibres with carbon or silicon carbide (SiC), for example.
CVD coatings are high-temperature processes. They require temperatures of 500°C and above, as well as a very high energy input. A vacuum in the process chamber reduces the boiling point and facilitates the transition of precursor substances into the gas phase whilst also preventing undesirable chemical reactions.
In contrast to the PVD process, chemical vapour deposition allows for conformal coating of even complex shapes and three-dimensional surfaces. CVD processes can also create very fine structures on wafers.
A prerequisite for CVD coating is the availability of the suitable precursor which provides all components of the desired layer in the process chamber. For example, ammonia and dichlorosilane are used as precursors for the deposition of silicon nitride. Tin chloride or tin organic compounds and oxygen or water vapour are the precursors used for depositing thermal insulation coatings of tin oxide on flat glass. Thin layers of tin oxide also protect glass containers in filling systems from potential damage caused by impacts and other mechanical stresses.
Since the condition of the substrate surface affects the layer growth, an appropriate process design can enable the targeted growth of metals in specific sections of the surface; this could be, for example, only in electrically conductive areas and not in insulating areas. This capability of selective coating makes CVD and PECVD particularly interesting for microelectronics.
FHR's CVD systems are individually designed based on customers' specific applications and their related process requirements. The sputtering coating technology can often be supplemented by a CVD/PECVD process compartment. FHR offers customers outstanding tool quality and the use of high-quality, reliable components, all at competitive prices.