Guangdong Zhi Neng: Global debut of silicon-based vertical GaN HEMT power device technology

According to the official WeChat account of Guangdong Zhi Neng Semiconductor Co., Ltd., Dr. Li Zilan, founder of Guangdong Zhi Neng, recently participated in and gave an invited talk at the 15th International Conference on Nitride Semiconductors (ICNS-15) held in Sweden. The report shared the team's original breakthroughs and application prospects in silicon-based vertical gallium nitride power devices (GaN HEMT) technology.

The Guangdong Zhi Neng team has pioneered the direct epitaxial growth of vertical GaN/AlGaN heterostructures and vertical two-dimensional electron gas channels (2DEG) on silicon substrates. Through precise process control, they have fabricated gallium nitride fin structures with low dislocation density. This method offers a high degree of freedom in epitaxial structure design.

Based on this innovative platform, the team successfully developed the world's first normally-on device (D-mode VHEMT) and threshold voltage adjustable normally-off device (E-mode VHEMT) with vertical 2DEG channels. In terms of process integration, selective etching of source/gate electrodes and complete removal of the silicon substrate have been achieved, resulting in a fully vertical electrode structure layout, which can significantly improve device heat dissipation efficiency. This innovative technology, supported by an advanced process platform, has high mass production feasibility and also provides broad space for device miniaturization and high-current performance iteration (power density).

Image source: Guangdong Zhi Neng Semiconductor Co., Ltd.

Figure 1 (left) x-SEM structure, Figure 2 (right) silicon substrate removal

Guangdong Zhi Neng showcased the world's first vertical two-dimensional electron gas gallium nitride power device structure (as shown in Figure 1), at which point the silicon substrate used for growth had not yet been removed. Figure 2 shows the vertical gallium nitride device wafer, where the silicon substrate used for growth has been removed, and the observation surface is the original silicon substrate surface.

Guangdong Zhi Neng introduced that currently widely used gallium nitride power devices mostly adopt a lateral structure, but they still face technical bottlenecks such as electric field management, device miniaturization, and heat dissipation difficulties in high-power, high-current scenarios, making it difficult to fully utilize the performance advantages of gallium nitride materials. In contrast, the vertical gallium nitride device architecture can break through the limitations of the lateral structure in conductivity (power density) and heat dissipation performance, exhibiting excellent performance and system integration potential by orders of magnitude, and is considered one of the key technical paths to push gallium nitride power devices towards higher power.

Guangdong Zhi Neng pointed out that, surrounding the above-mentioned vertical gallium nitride device architecture and process, the company has laid out multiple core intellectual property rights domestically and internationally, building a solid technological barrier. With continuous innovation in material epitaxy, structural design, and process integration, the vertical gallium nitride power device platform is expected to become a key technological path for the next generation of high-performance gallium nitride power devices.