Carbon tetrabromide — CBr4

SAFC Hitech® Carbon tetrabromide is available in a wide range of ultra-high purity grades and is supplied to customers worldwide through our network of local distribution facilities.

To accommodate the range of customer requirements, SAFC Hitech has invested in production and filling facilities capable of handling a wide variety of different containers, specializing in fill quantities between 25g and 25kg.

Carbontetrabromide
Tetrabromomethane
CBr4

Carbon tetrabromide (CBr4) has been shown to be highly effective as a p-type dopant source in various III-V alloys.

Carbon doping offers several advantages over other elements due to its low diffusivity[1] and the ability to readily incorporate high concentrations.

CBr4 is sufficiently versatile to be useful in both MOVPE[2] and CBE[3] deposition techniques, with the latter allowing access to slightly higher doping levels (1020cm-3). Such high levels of carbon facilitate ohmic contact formation and reduce parasitic sheet and bulk resistances in device structures such as HBTs[4]. Optimization of deposition parameters is key to minimize the etching effect associated with CBr4 use as this significantly influences the growth chemistry[5].

SAFC Hitech has manufactured CBr4 since 1985. During this time we have continued to incorporate and install the latest technologies in process equipment design and operational control to yield efficient and reliable plants that can run continuously. Built-in redundancy, modular design and multiple production locations ensure an uninterrupted supply of CBr4. SAFC Hitech has a simple, effective way of manufacturing CBr4 from the basic raw materials ensuring impurity sources are at a minimum. Furthermore, SAFC Hitech employs specially developed purification processes for CBr4 that yield the lowest levels of oxygen-containing species in the final product. The proven technique of adduct purification is also used to ensure the lowest levels of metallic and hydrocarbon impurities on a consistent basis.

CBr4 is certified in-house using the latest analytical techniques, and periodic film growth ensures the validity of the methods and that the CBr4 is capable of producing state-of-the-art device structures.

SAFC Hitech employs the latest analytical techniques with ultra-low detection limits for all the potential contaminants in CBr4.

CBr4 is sampled and analysed during and post manufacture to ensure the highest final product specification and reliability. The analysis is performed using a wide variety of physical characterisation techniques including ICP-OES, ICP-MS, NMR, TGA, vapour pressure, GC-AED and AA, on state-of-the-art tools specially upgraded for CBr4 impurity detection.

Considerable effort has been expended to develop suitable methodologies to provide accurate, reproducible data for the different grades of product available. As for many of its manufactured products, SAFC Hitech regularly reviews the analytical data it collects and can provide SPQ data to its customers.