Silicon-based GaN Epitaxial Susceptor

Vetekseicon's Silicon-based GaN Epitaxial Susceptor is a key component in VEECO's K465i GaN MOCVD system for supporting and heating the GaN material's silicon substrate during epitaxial growth. Moreover, our GaN on Silicon Epitaxial Substrate utilizes high-purity, high-quality graphite material as the substrate, which provides good stability and thermal conductivity during the epitaxial growth process. The substrate is able to withstand high-temperature environments, ensuring the stability and reliability of the epitaxial growth process.

Ⅰ. Key roles in Epitaxial Process

(1) Provide a stable platform for epitaxial growth

In the MOCVD process, GaN epitaxial layers are deposited onto silicon substrates at high temperatures (>1000°C), and the Susceptor is responsible for carrying the silicon wafers and ensuring temperature stability during growth.

The Silicon-based Susceptor utilizes a material that is compatible with the Si substrate, which reduces the risk of warpage and cracking of the GaN-on-Si epitaxial layer by minimizing the stresses caused by coefficient of thermal expansion (CTE) mismatches.

(2) Optimize heat distribution to ensure epitaxial uniformity

Since the temperature distribution in the MOCVD reaction chamber directly affects the quality of GaN crystallization, SiC coating can enhance thermal conductivity, reduce temperature gradient changes, and optimize epitaxial layer thickness and doping uniformity.

The use of high thermal conductivity SiC or high purity silicon substrate helps to improve thermal stability and avoid hot spot formation, thus effectively improving the yield of epitaxial wafers.

(3) Optimizing gas flow and reducing contamination

Laminar flow control: Usually the geometric design of the Susceptor (such as surface flatness) can directly affect the flow pattern of the reaction gas. For example, Semixlab's Susceptor reduces turbulence by optimizing the design to ensure that the precursor gas (such as TMGa, NH₃) evenly covers the wafer surface, thereby greatly improving the uniformity of the epitaxial layer.

Preventing impurity diffusion: Combined with the excellent thermal management and corrosion resistance of Silicon Carbide Coating, our high-density silicon carbide coating can prevent impurities in the graphite substrate from diffusing into the epitaxial layer, avoiding device performance degradation caused by carbon contamination.

Ⅱ. Physical properties of Isostatic graphite