Editor’s Note
As the semiconductor industry seeks materials to surpass silicon’s limits, diamond emerges as a promising candidate for next-generation power electronics. This article explores its potential to redefine performance in electric mobility and renewable energy systems.
Just as we moved from silicon to wide-bandgap SiC and GaN to enable decisive advances in electric mobility and renewable energy, the next frontier could well be crossed thanks to the hardest form of carbon, paving the way for the ultimate platform for power semiconductors. With 40 years of experience in power electronics, Patrick Le Fèvre, Marketing and Communications Director at Powerbox, has witnessed the radical transformations that have reshaped the power electronics landscape. In an exclusive for ViPress.net, he provides a detailed overview of diamond-based semiconductors and the latest developments.
For over forty years, I have witnessed the radical transformations that have reshaped the power electronics landscape. It all started with bipolar transistors, then MOSFETs appeared, before entering the era of wide-bandgap (WBG) semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN). Each technological evolution has enabled improved performance, increased efficiency, and miniaturization of power systems. But today, we are on the cusp of what could be the next leap forward in power device performance, towards the mythical 99.99% efficiency: the use of synthetic diamond as a semiconductor material, a truly exciting new concept for power electronics engineers.
The idea may seem exotic, even far-fetched. After all, diamond is traditionally associated with jewelry, industrial applications such as abrasives and cutting, drilling, grinding, and polishing machines, or with laboratories for high-pressure experiments, but not with power conversion systems or radio frequency amplifiers.
However, for many years, the scientific community has recognized diamond as the material of choice for thermal dissipation, thanks to its thermal conductivity, which is significantly higher than that of conventional materials like silicon. Nevertheless, the inherent hardness of this material and the complexity of its processing have, until now, made it unsuitable for use in semiconductor technology.
Before addressing the question of performance and benefits, it is essential to present a summary of the evolution of diamond use in technological applications. The story begins in 1954, when General Electric (GE) succeeded in creating the first synthetic diamond using the HPHT (High Pressure High Temperature) method, marking the first artificial manufacture of diamonds. After this milestone, the 1980s saw the first expansion of diamonds via the Chemical Vapor Deposition (CVD) method, followed by the exploration of doping processes in the 1990s. Subsequently, those involved in the development of synthetic diamonds deepened their knowledge of this material in terms of characterization, fabrication, and processing.
However, advances in materials science and manufacturing techniques are rapidly transforming synthetic diamond into a serious candidate for the future of semiconductors. Let’s explore why diamond is considered an exceptional material, how it compares to conventional and established WBG semiconductors (SiC and GaN), and what obstacles remain to be overcome before it can reach commercial maturity.
We used to say that the evolution of power electronics resembles a staircase with major leaps that bring new technologies from research to market to improve performance. Diamond semiconductors could be considered the next step, but some believe the challenge is too great to become reality.
It is important to note that SiC and GaN did not achieve immediate success. When SiC power diodes first appeared on the market in the late 1990s, they were expensive, difficult to manufacture, and had reliability issues. GaN’s commercial journey began later, with initial adoption in RF applications, then evolving into high-efficiency power transistors for all types of applications, from fast chargers to data center power supplies.
There is no doubt that conventional silicon semiconductor technology is well-established and constantly improving through new technologies, even though the success of SiC and GaN was driven by an industry that needed higher voltages, superior efficiency, and higher switching frequencies to reduce the size of end equipment. Today, SiC and GaN are present in all areas, from electric vehicles to solar inverters. WBG materials offer significant advantages in terms of size, weight, and power (SWaP), and we all benefit from powerful, compact, and energy-efficient USB adapters.
