Compound Semiconductors
Full range of group III/V and II/VI plus broad dopant offering
The roots of DOCK go back to alternative group V chemistry, such as TBAs and TBP. Throughout our almost 30-year-long history, our portfolio for compound semiconductors has grown steadily. Today, we are the only one-stop-shop for any kind of compound semiconductor deposition process. DOCK uniquely offers the full range of liquid/solid precursors and is constantly engaged in improving the purity of standard precursorsas well as supplying improved molecules or completely new precursors for novel material systems (e.g. a range of Sc precursors for the growing field of AlScN semiconductors).
01.
Renewable Energy/Energy Conversion
1.1. Solar Cells
Alloying of III/V semiconductors is a powerful technique to adjust the material properties and allows the fabrication of multijunction solar cells. In multijunction solar cells the limitations of singlejunction cells are overcome by optimizing each junction for absorption in a specific wavelength window. Growing thick dislocation-free layers requires lattice matching of all individual layers and a suitable substrate. Potential candidates are GaAs, (Ga,In)P, (Ga,In)As, (Ga,In)(P,As) and more… Choosing the right dopant is crucial for the device’s performance and we are happy to discuss possible solutions with you.
CdTe and CdSe were successfully applied to thin-film solar cells. Advantages are high stability, low manufacturing cost, and high light absorption.
02.
Optoelectronic Devices
2.1. Laser/LED
III/V semiconductor laser diodes are widely applied in our digital society. Especially (Ga,In)(P,As) is essential for telecommunication. There are plenty of materials available spanning from the UV to the IR region. For lower growth temperature we suggest using precursors featuring larger alkyl groups e.g. tritertiarybutylgallium(TTBGa), effectively reducing the carbon incorporation.
III/N semiconductors are attractive wide band gap materials for various applications. GaN offers the potential for blue VCSEL structures. Crucial is the n-doping of the AlInN/GaN DBR to achieve a high conductivity using group IV elements such as Si. Another bright application are GaN-based transistors in high power devices. Moreover, HVPE allows the growth of other III/V semiconductors with a superior growth rate in comparison to other epitaxy methods.
2.2. Detector
Mercury Cadmium Telluride (MCT) is well known for its application as infrared detector material. For the integration on a suitable substrate (Sapphire and GaAs are transparent in the 3 – 5 µm and 8 – 14 µm range, respectively) high-quality growth of CdTe is essential. The grown structure is flipped onto a Silicon readout integrated circuit.
03.
Doping (Group II/VI Dopants and Group III/V Dopants)
High purity and the right molecule are key to the highest device performance. DOCK takes special care in DOPANT synthesis, purification, and novel precursor development. There is a vast number of dopants with varying ligand modifications available and we are happy to discuss this essential choice with you.
04.
Etching
Selective area growth is an important method in advanced device manufacturing. DOCK offers mild etching alternatives to the standard gases in use. Furthermore, in-situ substrate cleaning is possible.
Examples of our range: TBCl
05.
Surfactant
A Surfactant (surface active agent) shows several effects during growth. It helps to smoothen the surface, reduces carbon incorporation, or changes the growth rate. Large elements that tend to segregate to the growth surface are best suited for surfactant applications because the incorporation is insignificant.
For the growth of III/V semiconductors Sb and Bi are the most prominent chosen surfactants.