​AI Data Centers Drive Demand for SiC, GaN Power Semiconductors

Power consumption is rising with the spread of artificial intelligence (AI) data centers, highlighting the importance of compound power semiconductors such as silicon carbide (SiC) and gallium nitride (GaN). Data centers are adopting high-voltage power networks to deliver more electricity efficiently. Conventional silicon (Si) power semiconductors have limitations in reducing power losses.

​Bae Sung-beom, a senior principal researcher at the Electronics and Telecommunications Research Institute (ETRI), said Oct. 7 at the Korea Power Device Industry Association's Power Semiconductor Industry-Academia-Research K-Forum at Hotel Nongshim in Busan that the growth of the AI industry is causing power shortages worldwide. “Because it is difficult to expand power infrastructure at the pace of actual demand growth, it is becoming increasingly important to use limited energy efficiently,” Bae said.

​Data centers operate large-scale computing resources such as graphics processing units (GPUs) around the clock. As AI models grow larger, the amount of GPUs and storage capacity required by data centers increases, driving up power consumption. How efficiently electricity supplied from external power grids can be delivered to servers with minimal losses is also becoming increasingly important.

​Improving power efficiency requires reducing losses that occur when electricity from outside is converted to voltages that servers or GPUs can handle. NVIDIA's 800-volt direct-current (DC) data center power architecture has emerged against this backdrop. The 800V DC system distributes electricity inside data centers at a higher 800-volt DC voltage than conventional systems. It simplifies the existing power-supply architecture and transmits electricity at higher voltage, reducing losses during power conversion and wiring.

​As power-supply voltages rise, the role of power semiconductors becomes more important. Improving power efficiency in high-voltage and high-power environments has limitations because designing devices to withstand higher voltages makes it more difficult to reduce power losses and heat generation.

​Compound power semiconductors such as SiC and GaN are being considered as alternatives. They can operate at higher voltages and temperatures than Si and reduce losses during power conversion. Their ability to switch at high speeds also helps improve the efficiency of power-conversion equipment and enables smaller components.

​Applications vary depending on voltage levels and power-conversion stages. SiC is suited to high-voltage, high-power environments. It can be used in equipment that converts electricity supplied from external power grids at thousands to tens of thousands of volts into power that can be used inside data centers. GaN offers fast switching performance at relatively lower voltage levels. It can help reduce power losses when voltage is stepped down inside servers to levels required by GPUs and other computing devices.

​Reliability issues need to be addressed for commercialization. Compound semiconductors are manufactured by combining different materials to form devices. Differences in the coefficients of thermal expansion between materials can cause wafers to warp or crack. The thermal conductivity of substrates also affects device output and efficiency. The industry is researching ways to address these issues using new substrate materials and vertical device structures.