Components for epitaxial processes

The epitaxial processes MOCVD and MBE play a vital role, for example, in the manufacture of LED chips, transistors, solar cells, and other optoelectronic components. These processes are used to create crystalline semiconductor layers. The abbreviation MOCVD stands for metal organic chemical vapor deposition. MBE stands for molecular beam epitaxy. During these processes, the materials in the epitaxial reactor chamber are exposed to extreme heat. Our temperature resistant components made of refractory metals make a vital contribution here to ensure a reliable, efficient process.

Your advantages at a glance:

Simulation with the finite element method (FEM)
Customized designs and tailored solutions
Patented coating process
Cost savings due to decreased operating temperature
Cost savings due to increased service life
Higher yield per coating cycle

The heating elements in a MOCVD system are heated to 2000°C. These high temperatures make our molybdenum and tungsten high-performance materials indispensable for various shieldings, gas collectors, and heating elements. Plansee supplies over 50 different components for MOCVD. We are a recognized OEM for MOCVD systems as well as active in the spare parts market. We are also more than just a substitute for our customers because of our improved technical designs and patented coatings.

Customer-specific designs for a homogeneous temperature distribution

The semiconductor layer in an LED needs to be able to transmit light at approximately the same wavelength. An important prerequisite for this is homogeneous temperature distribution in the MOCVD system. Any deviation in the temperature profile will lead to a change in the color of the light being emitted later on. Our engineers use elaborate calculations to simulate the MOCVD process of the respective system with the help of the finite element method (FEM) to improve the design of our heating components. The new components increase temperature homogeneity in the reactor chamber. The customer profits from a higher yield per coating cycle, thus ensuring higher productivity.

We work together with our customers to develop customized designs for heating elements as well as other components for the MOCVD reactor.

Simulations, components for epitaxial processes

Increased service life

The more effective heating elements radiate heat, the less they have to be heated. Plansee has developed a patented coating process to maximize thermal output.

The tungsten-based layer is characterized by high porosity, which greatly increases the surface of the heating element. The effect of this is that the surface emissivity increases, the operating temperature decreases, and the service life of the heating elements is increased by several additional months.

Materials in an epitaxial reactor chamber must be able to withstand temperatures of up to 2200°C. That's not a problem for Plansee. We produce temperature-resistant components made of molybdenum, tungsten, and special alloys for your system. The advantages:

High melting point:
molybdenum (melting point: 2620°C) and tungsten (melting point: 3420°C) are refractory metals whose high melting points make them ideally suited for use in high-temperature processes like MOCVD and MBE.

Corrosion resistance:
molybdenum and tungsten are corrosion-resistant in a variety of atmospheres even at very high temperatures:

	Molybdenum	Tungsten
Ammonia gas	Up to 1000°C (1273 K) no reaction over 1000°C (1273 K) possible surface nitriding	Up to 1000°C (1273 K) no reaction over 1000°C (1273 K) possible surface nitriding
Noble gases	Up to the highest temperatures no reaction	Up to the highest temperatures no reaction
Carbon dioxide	Oxidation at over 1200°C (1473 K)	Oxidation at over 1200°C (1473 K)
Carbon monoxide	Oxidation at over 1400°C (1673 K)	Oxidation at over 1400°C (1673 K)
Hydrocarbons	Carburation at over 1100°C (1373 K)	Carburation at over 1200°C (1473 K)
Air and oxygen	Oxidation at over 400°C (673 K) sublimation at over 600°C (873 K)	Oxidation at over 500°C (773 K) sublimation at over 850°C (1123 K)
Nitrogen	Up to the highest temperatures no reaction (also applies to pure molybdenum)	Up to the highest temperatures no reaction (also applies to pure tungsten)
Water vapor	Oxidation at over 700°C (973 K)	Oxidation at over 700°C (973 K)
Hydrogen	Up to the highest temperatures no reaction (note dew point)	Up to the highest temperatures no reaction (note dew point)

High purity:
impurities in reactor components may also contaminate the semiconductor during operation. To guarantee the quality of the semiconductors and the efficiency of the LEDs or transistors, our materials must be free of impurities. We guarantee a purity of over 99.97%.
Low vapor pressure:
our materials are ideally suited for use in high and ultra-high vacuums.

Special dimensional stability requirements?

Molybdenum and tungsten keep their shape even at high temperatures and when exposed to frequent cooling and heating cycles. We have extended the service lives of our materials even further with special alloys such as TZM, WVM, ML, and WL. They offer outstanding creep resistance and material strength.