Next Generation Power Semiconductors: Sanken's Commitment to GaN/SiC Development


1. Next Generation Power Semiconductors: What is GaN / SiC?

GaN / SiC with excellent characteristics

- History of Semiconductors - From germanium to silicon
History of semiconductors began around 1950 with the introduction of the point contact germanium transistor, later shifting to the use of silicon which has become commonly used due to its excellent characteristic.

Silicon semiconductor products have evolved over time, with the creation of high precision semiconductor manufacturing equipments and the optimization of device configuration and wafer process. This contributed to the development of miniaturized and high performance electronic products which have become a major part in our daily lives.

-The Future- Next Generation Power Semiconductors GaN SiC
In recent years, GaN (gallium nitride) and SiC (silicon Carbide) based semiconductors called the "Next Generation Power Semiconductors"have been receiving much attention.
Compared to silicon, GaN and SiC have a wider band gap (Si:1.1, SiC:3.3, GaN:3.4), and therefore it is also called "Wide Band Gap Semiconductors".
Comparing the material properties, the figure of merit (εμeEc3) of SiC is 440 times greater, and GaN is 1130 times than that of Silicon.
To fully utilize this material, development in the area of peripheral technology is currently underway. A more compact and highly efficient equipment can be created, by replacing conventional Si(Silicon) semiconductors with a GaN or SiC based new generation power semiconductor.
The next generation power semiconductors are expected to open up a new field of opportunities for electronic equipments.

What if silicon devices are replaced by SiC devices?

Since SiC devices have significantly lower loss compared to silicon devices,
replacing your power semiconductor with SiC devices can drastically reduce the size of your equipment.

Ranges of Silicon/SiC/GaN devices

In a SiC, half of the silicon material is replaced with carbon. By combining carbon, it allows a robust crystalline figure to be created, thus having a more precise and stable crystal compared to silicon.
Therefore, critical electric field for breakdown is higher by one order of magnitude, and can create an extremely thin active layer.
This enables a low loss, high breakdown voltage device to be created, compared to conventional silicon devices.
⇒SiC device has an advantage in high breakdown voltage/ high power applications, such as in motor drive applications.

On the other hand, GaN shows more connective stability, and has an even higher critical electric field for breakdown than SiC.
Today, forming a GaN active layer on silicon substrate has become the standard.
Therefore, although GaN does not have as much ability to withstand high breakdown voltage when compared to SiC, it is suited for compact, high frequency applications.
⇒GaN device has the advantage in compact, high frequency applications, such as in switching power supply.

2. History of Sanken Electric's Next Generation Power Semiconductor Development

As a semiconductor manufacturer with more than 60 years of history since its establishment, Sanken Electric has been involved in the development of the next generation power semiconductors before year 2000.

The origin of Sanken Electric's GaN power devices trace to the blue LED Si substrate technology. Sanken was the first in the industry to develop InGaN on Silicon LED (Patented by Sanken Electric), a gallium nitride compound mixed with indium on a silicon substrate. This has contributed to making a low cost blue LEDs possible.
From 2002, with support from NEDO, Sanken has begun development of power devices, and from 2004, Sanken has announced the results of their efforts, in various fields from high breakdown voltage devices, to applications of motor and power supply units.

Regarding SiCs, Sanken has been involved in NEDO's next generation power electronics technical development project from 2009, while working in parallel with development of SiCs, and the introduction of power supply applications. 
Mass production of SiC SBD began in Dec, 2013.
NEDO: New Energy and Industrial Technology Development Organization