PECVD Deposition Systems
1) RF Plasma Process Chamber
• Radio frequency plasma excitation
• Substrate temperature up to 600 °C
• Substrate to electrode distance 1-5 cm
2) MW - PECVD System
• Microwave plasma excitation
• Substrate temperature up to 1000 °C
• Substrate to source distance 1-30 cm
• Water cooled chamber
Thin film electronic devices are formed by several layers of materials with different characteristics, such as a-Si:H, micro-cry-Si:H, a-Si C :H, micro-cry-Si N :H, a-C:H, DLC. These materials form the active layers in photovoltaic solar cells, sensors, detectors, LED’s, thin film transistors, etc. These devices, in addition to p-doped, intrinsic and n-doped semiconductor layers, typically consist of several other layers, such as insulator layer, Transparent Conductive Oxyde (TCO) layer, and metal layer. The technique of radio frequency plasma enhanced chemical vapour deposition (RF-PECVD) is commonly used for the deposition of hydrogenated amorphous or microcrystalline silicon and its alloys such as silicon carbide and silicon nitride; more recently other techniques such as VHF-PECVD, ECR-PECVD, MW-PECVD, HWCVD are being increasingly used for the deposition of these materials.
The extensive work carried out both in research laboratories and in industry has resulted in the development of a wide range of deposition systems with widely varying features and many different reactor structures have been proposed to improve the quality of plasma deposited thin film materials and devices. The main part of a deposition system consists in a vacuum chamber evacuated by a pumping unit to some appropriate vacuum level. After achieving the desired ultimate vacuum, the process gas mixture is introduced via Mass Flow Controllers and the pressure is kept constant by a variable conductance valve. Plasma is then ignited by an RF generator (or other source capable of generating high energy electrons); process gas is decomposed in ions and radical which are then deposited as thin films.
The important figure of merit for any vacuum system, and in particular for a deposition chamber, is the total leak and degassing rate when the reactor is at deposition temperature: the ratio of this parameter to the process gas flow rate will largely determine the achievable purity of films deposited in that reactor.
Our PECVD systems features:
• UHV capability (10-9 mbar)
• Dedicated or additional Hot Wire CVD
• Substrate size from 10 cm x 10 cm up to 30 cm x 30 cm
• Process temperature: standard up to 500°C, optional up to 1000°C
• Modular process gas manifold with mass flow controllers
• Automatic process pressure control by throttle valve and capacitance manometer
• Turbomolecular pumping for ultimate vacuum and during process
• Deposited material quality and homogeneity guarantees
• PECVD Multichamber system