The fused quartz caps are engineered components designed to securely seal quartz tubes, reactors, and wafer boats during high-temperature semiconductor and photovoltaic processing. Made from ultra-high purity fused quartz, these caps provide excellent thermal shock resistance, chemical stability, and mechanical strength.

They ensure a tight, contamination-free seal that prevents gas leakage and maintains the integrity of the process environment during oxidation, diffusion, LPCVD, and annealing operations. The caps’ durability allows for repeated thermal cycling without deformation, supporting consistent process results and extended equipment life.

Common Issues in Fused Quartz Caps and How to Avoid them

1. Cracking Due to Thermal Shock

Cause: Rapid temperature changes or uneven heating.

Prevention: Preheat the furnace gradually and ensure uniform temperature distribution. Use high-quality, high-purity fused quartz to improve thermal shock resistance.

2. Surface Contamination

Cause: Particles, chemical residues, or impurities from process gases.

Prevention: Clean caps before use with ultra-pure chemicals, maintain a cleanroom environment, and avoid direct contact with contaminated surfaces.

3. Deformation or Warping

Cause: Excessive mechanical stress or prolonged exposure to high temperatures.

Prevention: Use precision-engineered caps designed for your furnace type and avoid over-tightening or improper installation.

4. Chemical Erosion

Cause: Aggressive process gases or repeated high-temperature exposure.

Prevention: Select high-purity, corrosion-resistant fused quartz, and monitor the chemical environment in the furnace.

5. Misalignment in the Furnace

Cause: Poorly fitted caps can cause uneven heat distribution and gas flow issues.

Prevention: Ensure caps match the furnace specifications and check alignment before every process run.