15" Quartz Bell Jar

Semicorex 15" Quartz Bell Jar is engineered to meet these challenges, providing a high-performance solution for mid-to-large scale batch processing where thermal uniformity and material purity are essential for maximizing yield. In the semiconductor and thin-film industries, the integrity of the process chamber is paramount. As wafer sizes increase and nodes shrink, the requirement for a clean, stable, and chemically inert environment becomes non-negotiable.

1. Material Science: The Purity of Fused Silica

The foundation of our bell jar is high-purity fused silica (Quartz). Unlike standard glass, quartz is composed almost entirely of SiO2, providing unique properties that are vital for semiconductor fabrication:

Ultra-Low Contamination: Our quartz is processed to minimize metallic trace elements (such as Al, Fe, Na, and K) to the parts-per-billion (ppb) level. This prevents the diffusion of impurities into the wafer during high-temperature cycles, ensuring the electrical integrity of the devices.

Superior Thermal Shock Resistance: Quartz possesses a near-zero Coefficient of Thermal Expansion (CTE). This allows the 15" Quartz Bell Jar to withstand rapid temperature ramping and quenching without the risk of fracture or structural fatigue—a critical requirement for high-throughput reactors.

Excellent Chemical Inertness: Quartz is highly resistant to most acids (with the exception of hydrofluoric acid) and corrosive process gases, ensuring that the chamber does not degrade or outgas during aggressive etching or deposition cycles.

2. Precision engineering and optical clarity

The 15" Quartz Bell Jar provides maximum volume and optimal gas flow dynamics for the purpose of batch wafer processing. The jar has a vertical chimney (also known as a neck) that is optimally designed to provide an inlet for gas or assist in extracting gas through a vacuum from the jar, which is shown in the image above.

Optical Transparency - The high level of transmission of quartz material to emit wavelengths in the ultraviolet, visible and infrared regions of the spectrum allows for real time processing as well as the use of external lamp heaters for rapid thermal processing (RTP).

Reinforced Sealing Surfaces - The neck of the jar has a specially developed opaque white seal (also referred to as a ground joint) that provides a hermetic (air-sealed) and vacuum-tight interface between the reactor baseplate and the jar.

Annealing for Stress Relief - All 15" Quartz Bell Jar undergo a rigorous thermal annealing process to relieve internal mechanical stress that has been placed on the jar by the mechanical process of blowing or shaping the jar, therefore significantly reducing the chance that a jar will spontaneously fail when placed under vacuum load.

3. Critical Applications in the Semiconductor Fab

Our 15" Quartz Bell Jar is specifically designed for integration into the following high-value processes:

Silicon Epitaxy: Providing a transparent, non-reactive vessel for growing high-quality single-crystal silicon layers.

Plasma Enhanced CVD (PECVD): Withstanding the corrosive plasma environment while maintaining high dielectric strength.

Diffusion and Oxidation: Serving as a clean, high-heat chamber for the formation of gate oxides and dopant drive-in.

Optical Fiber Preform Production: Ideal for the high-purity deposition of silica layers in the manufacturing of specialty glass.

At Semicorex, we handle each bell jar as a piece of precision laboratory equipment. Our process includes: Strict material sourcing with verified electronic-grade quartz ingots; advanced fabrication that merges traditional glass-blowing skills with CNC-controlled grinding and polishing; and thorough inspection using polarized light to detect residual stress and laser interferometry for precise dimensional checks.