Manufacturing Challenges and Technical Solutions for GaN HEMTs

News & Updates

December 16, 2025

Manufacturing gallium nitride high-electron-mobility transistors, or GaN HEMTs, is technically challenging. These challenges arise primarily from the intrinsic properties of the material itself, as well as from the complexity of the manufacturing process.

A GaN switch is built on a silicon substrate, on which a lateral two-dimensional electron gas, or 2DEG, channel is formed within an AlGaN/GaN heteroepitaxial structure. This channel features extremely high charge density and electron mobility.

Heteroepitaxial technology is used in the manufacturing process of GaN power switches, allowing GaN crystal material to be grown on different conductive crystal substrates. Most GaN devices are manufactured using GaN-on-Si technology. The reason for adopting GaN-on-Si is that silicon is abundant, cost-effective, and available in large wafer sizes. Silicon substrates provide a robust and reliable foundation for the production of next-generation GaN power devices. GaN power switches built on silicon substrates are able to achieve low on-resistance.

In recent years, significant progress has been made in growing high-quality GaN material on large-area silicon wafers. Combined with the development of CMOS-compatible processes, this technology supports the manufacture of high-performance and cost-effective hybrid power switches.

In a GaN HEMT, a conductive path is formed by an electron channel between the source and drain. The electron flow within this channel can be controlled by regulating the voltage between the gate and source. A GaN HEMT induces a high-electron-mobility channel between the source and drain, enabling a highly conductive drain-source path.

A high-resistivity pure GaN layer provides the foundation for the GaN transistor. Between this pure GaN layer and the large-size substrate, a thin aluminum nitride, or AlN, layer is grown as a buffer layer to isolate the GaN material from the substrate. A thin aluminum gallium nitride, or AlGaN, layer is then grown on top of the pure GaN layer.

Due to its piezoelectric properties, the AlGaN layer physically induces strain, attracting electrons at the interface between the two material layers and forming what is known as a two-dimensional electron gas, or 2DEG. This interfacial layer provides extremely low on-resistance due to its very high electron mobility and strong electric field strength.

The drain and source terminals of a GaN power switch are placed above the 2DEG layer, while the gate terminal is located above the AlGaN layer. To achieve a high-voltage GaN power switch, the distance between the drain and gate is typically increased. Although this distance increases, the on-resistance is not significantly affected because of the low resistance of the 2DEG layer. Turn-off is achieved by depleting electrons from the 2DEG channel.

Challenges in GaN Materials and Manufacturing Processes

The first challenge lies in the substrate. Although native GaN substrates are ideal, GaN has a high melting point and is difficult to grow into large-size, high-quality single crystals. As a result, native GaN substrates are extremely expensive and difficult to use in large-scale production. Therefore, GaN is typically grown on heterogeneous substrates such as sapphire, silicon carbide, or silicon. However, the lattice constants of these materials do not match that of GaN, which can lead to defects and reduce device performance and reliability.

Secondly, GaN epitaxial growth, especially when using metal-organic chemical vapor deposition, or MOCVD, requires extremely high temperatures as well as precise control of gas flow and purity. These growth conditions increase process complexity, equipment cost, and yield-related risks. Even the highest-quality GaN epitaxial layers still have a higher defect density than silicon materials. Although GaN devices can tolerate some defects, excessive dislocations may still affect device reliability and breakdown voltage.

Thirdly, because GaN devices have high power density, they generate a significant amount of heat within a small area. Efficient thermal management is difficult to achieve, especially when using sapphire or silicon substrates with relatively poor thermal conductivity. GaN is a hard and chemically stable material, making it difficult to etch and process using traditional silicon-based manufacturing techniques. Gate structure formation and insulation technologies are still under continuous development and often require additional process steps.

In addition, high-frequency and high-power GaN devices place higher demands on packaging technology. Special packaging is required to improve heat dissipation and reduce parasitic inductance and capacitance. Conventional silicon-based packaging technologies are often not well suited to GaN devices, increasing both product cost and process complexity.

THINKANTECH’s Technical Solutions

Despite these challenges, THINKANTECH has effectively addressed key difficulties in GaN manufacturing technology.

THINKANTECH’s GaN HEMT devices use silicon substrates because silicon offers low cost and large wafer sizes. By growing buffer layers, such as AlN or graded GaN layers, the company enables a gradual transition in lattice constants, thereby reducing dislocations.

THINKANTECH also adopts lateral epitaxial overgrowth, or LEO, technology, in which GaN is grown laterally across defect regions to reduce dislocation density. In its GaN manufacturing process, the company uses inductively coupled plasma, or ICP, etching and optimizes chemical etching processes to achieve cleaner and more precise GaN patterning.

THINKANTECH’s p-GaN gate technology enables normally-off, or enhancement-mode, operation, which is critical for power electronics applications. Low-inductance packaging technology is also used to reduce parasitic effects at high frequencies.

In addition, THINKANTECH further improves device performance and reduces product size through 3D packaging and integration technologies, enabling drivers and GaN devices to be integrated into a compact module.

One representative product is the XG045HB065G1, a 650 V GaN embedded half-bridge module that integrates two GaN HEMTs, two gate drivers, and one high-side gate voltage level shifter. This integrated solution helps simplify engineering design, reduce PCB area, and lower the number of power semiconductor devices required.

About THINKANTECH

THINKANTECH Technology is a manufacturer of wide-bandgap power devices, founded by experts in power semiconductors, market experts from the power supply industry, and a team of young professionals with entrepreneurial vision.

In 2022, the company was recognized as an above-designated-size enterprise. In 2023, it was listed as a National Technology-Based SME and a National High-Tech Enterprise, and obtained ISO 9001 quality management system certification. In 2024, THINKANTECH obtained IATF 16949 automotive-grade quality management system certification.

Since its establishment, the company has focused on the R&D and sales of power devices and modules, including Si MOSFETs and IGBTs, GaN HEMTs, SiC MOSFETs and SBDs, IGBT modules, and SiC modules. Its products are widely used in energy and power conversion applications across consumer electronics, photovoltaics, energy storage, automotive, AI servers, industrial automation, and other fields.

Headquartered in Nanjing, THINKANTECH has established branches in Shenzhen, Suzhou, Jiangsu, and other locations across China, while also extending its presence to North America and Taiwan. The company continues to expand its business footprint.

Contact

Nanjing Headquarters: 025-51180705

Shenzhen Branch: 0755-36991759

Email: THINKANTECH@x-ipm.com