Epitaxial Epi Graphite Barrel Susceptor

Epitaxial Epi Graphite Barrel Susceptor

Epitaxial Epi Graphite Barrel Susceptor is a specially designed support and heating device used to hold and heat semiconductor substrates during manufacturing processes like Deposition or Epitaxy processes.

Its structure includes typically cylindrical or slightly barrel-shaped, surface features multiple pockets or platforms for placing the wafers, can be solid or hollow design, depending on the heating method.

The main functions of epitaxial barrel susceptor:

1. Wafer Carrier and Temperature Control
The susceptor surface is designed with multiple wafer pockets (such as hexagonal or octagonal arrangement), which can support 6-15 wafers simultaneously. The high thermal conductivity of high-purity graphite (120-150W/m.K) ensures rapid heat transfer, combined with rotation function (5-20 RPM), resulting in a wafer surface temperature deviation of<± 1 ℃ and epitaxial layer thickness uniformity of<1%.

2. Optimization of reactant gas flow direction
The microstructure of the susceptor surface can break the boundary layer effect, allowing for uniform distribution of reaction gases (such as SiH4, NH3) and improving the consistency of deposition rate.

3. Anti pollution and anti-corrosion protection
Graphite substrates are prone to decomposition and release metal impurities (such as Fe,Ni) at high temperatures, while a 100μm thick CVD SiC coating can form a dense barrier to suppress graphite volatilization, resulting in a wafer defect rate of<0.1 defects/cm ².

Applications:
-Primarily used for silicon epitaxial growth
-Also applicable for epitaxy of other semiconductor materials like GaAs, InP, etc.

VET Energy use high purity graphite with CVD-SiC coating to enhance the chemical stability:

1. High purity graphite material
High thermal conductivity: the thermal conductivity of graphite is three times that of silicon, which can quickly transfer heat from the heating source to the wafer and shorten the heating time.
Mechanical strength: Isostatic pressure graphite density ≥ 1.85 g/cm ³, capable of withstanding high temperatures above 1200 ℃ without deformation.

2. CVD SiC coating
A β - SiC layer is formed on the surface of graphite by chemical vapor deposition (CVD), with a purity of ≥ 99.99995%, the uniformity error of coating thickness is less than±5%, and the surface roughness is less than Ra0.5um.

3. Performance improvement:
Corrosion resistance: can withstand high corrosive gases such as Cl2, HCl,etc, can extend the lifespan of GaN epitaxy by three times in the NH3 environment.
Thermal stability: The coefficient of thermal expansion (4.5 × 10-6/℃) matches graphite to avoid coating cracking caused by temperature fluctuations.
Hardness and Wear Resistance: The Vickers hardness reaches 28 GPa, which is 10 times higher than graphite and can reduce the risk of wafer scratches.