Cobalt is used in three main parts within a semi-conductor:
- The trend of increasing power by increasing the electric current in copper metal wiring is leading to electro-migration (e.g. ‘leaking’) of the copper. Cobalt is currently the material being extensively researched for its ability to provide a barrier to prevent the electro-migration of copper.
- Magnet tunnel junction transistors
- Cobalt - silicon - germanium nanowires can be used in optical electrical devices. Cobalt improves the contact interface and allows for a tuneable bandgap
As the semi-conductor industry has evolved, the size of semi-conductors has decreased. Two main driving forces are responsible:
- the smaller the semiconductor the lower the cost
- the smaller the semiconductor the more you can fit in a limited space
In 1970, Intel had created a semi-conductor of 10 µm. In 2015, the latest technology produced a semi-conductor nearly 1000 fold smaller at 11nm. To put these minute sizes into perspective, at 30nm, 3300 semiconductors will fit across the width of a human hair. The result is that much more information can be processed through much smaller surfaces, ultimately enabling miniaturisation.
With semi-conductors being so small, innovative methods of processing steps are required in adding cobalt. These include:
- physical vapour deposition (PVD): the use of an ion beam to evaporate and subsequently deposit the cobalt onto the target surface
- chemical vapour deposition (CVD): The use of reactant chemical species to deposit cobalt on the target surface
- atomic layer deposition: the deposition of cobalt at alternating atom-thick layers
- metal plating: the use of an electric current to deposit cobalt onto the target surface
Confidential Business Information
The semiconductor industry is highly competitive and relies on a solid base of research. Information is thus highly confidential and difficult to retrieve in the public domain. The sector is very innovative as it continues its search for better-performing technologies.