LED and other Compound Semiconductor Applications

LED

Metalorganic chemical vapor deposition or, more generally, metalorganic vapor phase epitaxy (MOVPE),is a chemical vapor deposition method of epitaxial growth of materials, especially semiconductors from the surface reaction of organic compounds and metal hydrides containing the required chemical elements. Formation of the epitaxial layer occurs by final pyrolisis of the constituent chemicals at the substrate surface. III-V MOVPE grown compounds include: GaAs; GaAsP; GaP; InP ; InGaAs; GaN; InGaN and many more. Metals and oxygenated carbon containing impurities should be reduced as much as possible. Dislocations and consequently poor optical efficiency and lifetime is the consequence of the presence of oxygen containing molecules during the epitaxial process.

Gases Used:

• Nitrogen (N₂)
• Hydrogen (H₂)
• Ammonia (NH₃)
• Arsine (AsH₃)
• Phosphine (PH₃)
• Hydrogen Chloride (HCl)
• Chlorine (Cl₂)

Power Devices

In speed, temperature and power handling, gallium nitride is set to take over as silicon power devices reach their limits. GaN is the technology that will allow us to implement essential future clean tech innovations where efficiency is a key requirement.The excitement regarding GaN stems from it's unique material and electronic properties. GaN devices offer five key characteristics: high dielectric strength, high operating temperature, high current density, high speed switching and low on-resistance. These characteristics are due to the properties of GaN, which, compared to silicon, offers ten times higher electrical breakdown characteristics, three times the bandgap, and exceptional carrier mobility.To reliably grow GaN on Si, precursor purity is essential. SAES Pure Gas supplies the purifiers necessary to maintain consistent precursor gas quality.

Gases Used:

• Nitrogen (N₂)
• Hydrogen (H₂)
• Ammonia (NH₃)
• Hydrogen Chloride (HCl)
• Chlorine (Cl₂)

Silicon Carbide (SiC)

Silicon carbide is used for ultrafast, high-voltage Schottky diodes, MOSFETs and high-temperature thyristors for high-power switching. These devices provide increased efficiency, reduced size and higher frequency in a variety of applications, such as  3-10kW solar power inverters, industrial motor drives, high-power DC data center power architectures non achievable with Si based devices. SAES Pure Gas supplies the purifiers necessary to maintain consistent process gas quality.

Gases Used:

• Nitrogen (N₂)
• Hydrogen (H₂)
• Methane (CH₄) with N₂ Removal
• Methane (CH₄) no N₂ Removal
• Hydrogen (H₂) / Propane (C₃H₈) mixture
• Silane (SiH₄)

Concentrated photovoltaic (CPV)

Concentrated Photovoltaic (CPV) technology uses optics such as lenses or curved mirrors to concentrate a large amount of sunlight onto a small area of semiconductor solar photovoltaic cells to generate electricity.
The solar cell typically consists of a Triple-Junction of semiconductor material on a Ge or GaAs wafer.  The most common technology to grow the epitaxial layers to make the Triple Junction is MOCVD, where gas purity is a must to guarantee an efficient and reliable process. SAES Pure Gas supplies the purifiers necessary to maintain consistent precursor quality.

Gases Used:

• Nitrogen (N₂)
• Hydrogen (H₂)
• Arsine (AsH₃)
• Phosphine (PH₃)