Tube Furnace for Wafer Oxidation, Silicon Doping, LPCVD, and Annealing

Wafer Tube Furnace showing Silicon Wafers inside the Quartz Tube

Tube Furnace for Wafer Oxidation, Silicon Doping, LPCVD, and Annealing

Semiconductor research and production typically require multiple furnaces for oxidation, silicon doping, LPCVD, annealing, and so forth.

But they often come at a staggering cost.

Multiple equipment types, limited cleanroom space, and tight budgets often keep semiconductor labs from working to their full potential. These constraints only grow tighter as the industry trends toward larger wafer diameters for greater chip yield.

SH Scientific offers space and cost-efficient tube furnaces for oxidation, silicon doping, LPCVD, annealing and more.

  • Compact footprints and self-contained cabinets maximize costly cleanroom space.
  • Standard tube diameters up to 8″, and larger upon request, accommodate all typical wafer sizes.
  • Tube length and zones are customizable for any conceivable treatment process or workflow.
  • Optional turn-key vacuum and gas flow systems provide complete atmospheric control.

From academic labs to industrial production settings, we supply the facilities that are driving semiconductor technology and education.

Tube Furnace Applications in Wafer Processing

SH Scientific wafer tube furnaces deliver versatility and uniformity of results in all common thermal processes.


An oxidation furnace helps forms a thin silicon dioxide (SiO2) layer, transforming wafers into functional semiconductors.

Dry oxidation, true to its name, occurs in a dry oxygen environment. It produces thin, uniform SiO2 layers suitable for applications like gate oxide production. Dry oxidation is particularly sensitive to temperature uniformity, lest the wafer develop irregular layers that adversely affect performance.

Wet oxidation introduces water vapor to quickly create a thicker SiO2 layer. This works best when a rapid growth rate is more important than absolute uniformity, such as with barrier layer applications.

Our tube furnaces can switch quickly between dry and wet oxidation.

Tube Furnace with Dry and Wet Wafer Diffusion Function
Tube Furnace with Dry and Wet Wafer Diffusion Function

The wet mode engages the bubbler, which delivers the requisite water vapor.

In either mode, you can expect uniformity and control for precise, repeatable results.

Temperatures may range from about 800° to 1200° C, but many customers process wafers at ~1150° C. Customized models are available for use at these higher temperatures, with a maximum of 1300° C and numerous tube sizes and heating configurations.

Silicon Wafer Doping

Diffusion is a common, low-cost technique to dope silicon wafers and thereby control their resistivity. Compared to ion implantation, diffusion doesn’t afford the same control over depth and concentration. But it’s considerably more manageable—especially in instructional settings.

Common silicon dopants are boron for p-type diffusion, as well as phosphorus, arsenic, and antimony for n-type diffusion. Several different dopants are also widely used with gallium arsenide and silicon carbide.

Their characteristics and trade-offs are beyond the scope of this article. Regardless of the materials and dopants at hand, certain furnace characteristics are critical. SH tube furnaces offer:

  • Temperature uniformity of ± 1° C in most configurations.
  • Digital mass flow controllers pre-programmed for 98 different gases.
  • Available high vacuum systems for applications such as nanostructure growth.

LPCVD, annealing, sintering, etc.

The same temperature, gas and vacuum management that facilitate oxidation and diffusion also make our tube furnaces ideal for:

  • Low pressure chemical vapor deposition (LPCVD), sometimes used sequentially with oxidation to create additional layers of SiO2, Si3N4, or polysilicon.
  • Annealing and rapid thermal processing for dopant activation.
  • Sintering for densification and structural refinement.
  • Curing to set polymeric materials.

A Compact Footprint for Space Efficiency

Many of our customers purchase packages of four furnaces: one each for n-type diffusion, p-type diffusion, oxidation, and annealing.

They’re often used inside a cleanroom, where floorspace is expensive and limited. We offer a self-contained cabinet that has a minimal footprint and is easily moved as your needs and workflows evolve.

This set-up is popular among our semiconductor R&D customers in general, and among university MEMS labs in particular.

Equipping Customers for Success

Above all else, we aim for excellent performance, at an accessible price, with comprehensive support. Judging by real-world purchasing decisions and feedback, our tube furnaces live up to that high standard.

For example, Kennesaw State University Engineering Technology Center recently purchased a 4” tube furnace for wafer oxidation. There were several suppliers to choose from, but none could offer more compelling value than SH.

We’re always eager to discuss innovations and specs and internal test data, but nothing speaks louder than major institutions placing their trust in SH Scientific.

Partnering With Us

SH Scientific makes it cost-effective to equip instructional and research facilities with state-of-the-art tube furnaces for silicon oxidation and doping.

We—and our customers—believe that no other line offers greater precision, control, and support at a competitive price.

To discuss your facility’s needs or potential customizations, please contact our US sales team today.