Applications of Aluminum Nitride in the Semiconductor Industry

Electronic Packaging Substrates

With the rise and application of power devices—particularly third-generation semiconductors—semiconductor devices are increasingly trending toward high power, miniaturization, integration, and multifunctionality. This evolution places higher demands on the performance of packaging substrates. Common ceramic materials used for electronic packaging substrates include aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4), beryllium oxide (BeO), and silicon carbide (SiC).

Compared to other ceramic materials, AlN boasts superior thermal conductivity; its theoretical thermal conductivity at room temperature can reach up to 320 W/(m·K)—eight to ten times that of alumina ceramics—while thermal conductivity in actual production can reach as high as 200 W/(m·K). Additionally, AlN ceramics feature high hardness, a coefficient of thermal expansion close to that of silicon, high volume resistivity, a low dielectric constant, and low dielectric loss. Furthermore, the material is non-toxic and resistant to high temperatures and corrosion. Its comprehensive performance surpasses that of alumina and beryllium oxide, making it an ideal material for next-generation semiconductor substrates and electronic device packaging.

Semiconductor Equipment Components

Due to their unique physical and chemical properties, aluminum nitride ceramics play an increasingly vital role in the semiconductor industry. In the field of semiconductor manufacturing, the electrostatic chuck (ESC) is a critical component; its design and material selection are pivotal to the stability and efficiency of the entire production process. Given that electrostatic chucks must operate stably in plasma environments and amidst high-temperature, corrosive gases, the materials used must possess resistance to thermal shock, plasma bombardment, and chemical corrosion.

Alumina and aluminum nitride are the mainstream materials for electrostatic chucks. Among them, aluminum nitride (AlN) ceramic is considered the preferred material due to a suite of excellent properties, including high thermal conductivity, superior chemical stability, low dielectric loss and dielectric constant, and a coefficient of thermal expansion close to that of silicon. These characteristics not only ensure the structural integrity and functional stability of the electrostatic chuck under extreme operating conditions but also enhance the overall performance and reliability of the semiconductor manufacturing process. To optimize AlN ceramics for use in Johnsen-Rahbek (J-R) type electrostatic chucks, it is necessary to produce dense ceramics with a room-temperature resistivity in the range of 10⁸ to 10¹² Ω·cm at lower sintering temperatures.

Semiconductor Substrate Materials

In recent years, aluminum nitride (AlN) has emerged as a highly promising next-generation ultra-wide bandgap semiconductor and a critical strategic material, thanks to its exceptional properties. With a room-temperature bandgap of 6.2 eV, AlN possesses outstanding electrical, thermal, and acousto-optical properties that compensate for the physical limitations of first- and second-generation semiconductor materials, such as silicon and gallium arsenide.

Aluminum Nitride (AlN) Thin-Film Materials

AlN thin films are direct-bandgap semiconductor materials that exhibit excellent mechanical, electrical, and optical properties. While GaN-based blue and green light-emitting devices have advanced rapidly in recent years, the growth of GaN faces a bottleneck due to the lack of suitable substrates. Given the excellent lattice and thermal matching between AlN and GaN, the growth of high-quality AlN thin films is of great significance; they can serve as buffer layers to enhance GaN crystal quality, thereby improving the performance of devices such as detectors.

With its multi-functional properties of “heat dissipation + insulation + wide bandgap”, aluminum nitride is known as the “core” of solid-state light sources, power electronics, and microwave radio frequency devices. It is the forefront of global semiconductor technology research and the focus of strategic competition. As the demand for AI computing power explodes, heat dissipation has become a core technology as important as transistor design. Although it currently faces challenges in preparation cost and process maturity, it has great development prospects in solving the “thermal management” and “high-frequency and high-voltage” bottlenecks of future semiconductors.