CVDteknikker

CVD techniques refer to a family of processes in which a solid film is deposited on a substrate from gaseous precursors. In a typical chemical vapor deposition process, precursor gases react or decompose on or near the substrate surface, forming a thin solid layer and releasing volatile by-products that are removed from the reaction chamber.

Common CVD variants include low-pressure CVD (LPCVD), atmospheric-pressure CVD (APCVD), and plasma-enhanced CVD (PECVD). LPCVD operates at reduced pressure to improve film uniformity on large-area wafers; APCVD runs near atmospheric pressure and can simplify hardware but may introduce higher particle densities. PECVD uses plasma to promote film growth at lower temperatures, expanding capability for temperature-sensitive substrates.

Metal-organic CVD (MOCVD) uses metal-organic precursors to grow complex oxide and III–V semiconductor films, and rapid-thermal CVD (RTCVD) emphasizes fast heating and cooling to boost throughput.

Applications span semiconductor devices (transistors, diffusion barriers, epitaxial layers), LEDs and solar cells, protective and optical coatings, and MEMS. CVD often provides conformal coatings with good step coverage on textured or three-dimensional structures.

Process parameters include precursor chemistry, substrate temperature, chamber pressure, carrier gas flow, and reactor geometry. Trade-offs involve film quality, deposition rate, equipment cost, and thermal budget, while safety concerns focus on toxic or flammable precursors and by-product handling.

Ongoing research integrates CVD with atomic layer deposition concepts, enables low-temperature growth, and explores new materials such as 2D layers and wide-bandgap semiconductors.