Substrate heaters are available as direct replacement components for common MBE systems. Veeco offers application-specific substrate heaters that are tailored for specific temperature and growth environment conditions. In the case of the standard heater, excellent thermal uniformity is achieved via a PBN diffuser plate and sophisticated filament design. The densely would tungsten wire filament provides a uniformly heated surface area. Wire is preferred over foil because its more consistent cross-sectional uniformity prevents hot spot formation. The filament assembly features closely spaced parallel wires arranged in a pattern which runs counter to rotation, assuring that both bonded and non-bonded blocks will be heated uniformly.Efficient power consumption is the hallmark of the substrate heater. Filament surface area is maximized and the heat shielding is designed to project thermal energy toward the substrate. Power/current consumption can be reduced by as much as 50 percent over that of OEM heaters. Background pressure is improved and the RHEED pattern is clearer with less inductive interference. Clean operation results from careful selection of construction materials and UHV-compatible manufacturing techniques. Only tantalum, tungsten and PBN are used in the hot zone of the heater used in standard III-V applications. Efficient operation also minimizes outgassing during growth.
The highly responsive tungsten wire filament enhances reliability and reproducibility. It is held firmly in place by an advanced isolation system, ensuring that performance characteristics will not be altered due to changing shape or position. The PBN diffuser plate protects the filament from being coated by the source material or accidental damage during substrate transfer.
Some of the optional substrate heater design enhancements include:
- Dual filament for optimization of heating flexibility
- Filament material for high temperature and alternative growth environments
- Diffuser material for alternative growth environments