How Quartz Tube Stations Work and the Benefits They Provide

Among the many processing steps involved in the manufacture of semiconductor components are high-temperature operations such as diffusion of materials into the silicon wafers. Quartz tubes are an ideal vessel for these process steps because the tubes can withstand the temperatures required and are inert enough to minimize contamination.

Typically, the silicon wafers are placed into a horizontal quartz tube large enough to hold the wafers and their supports. The quartz tube cleaning station can heat the contents up to over 1000 degrees centigrade. In a diffusion process, impurities such as phosphorus are introduced into the quartz tube.

Once the process is complete, the quartz tube is contaminated and has to be cleaned for the next batch of wafers. Complete and reliable cleaning is essential for the semiconductor manufacturing process because contaminating particles can cause defects in the semiconductor components or result in inferior product quality.

How Quartz Tube Cleaning Works

Quartz tube cleaning is a custom-designed process because the dimensions and cleaning requirements of quartz tube furnaces can vary widely. Quartz tubes are mechanically delicate, so they have to be handled with care. At the same time the cleanliness requirements are rigorous so that all traces of the contaminating material have to be removed. Finally, the rinsing and drying process must not introduce any new particles into the quartz tube. The cleanliness of the tube directly impacts the performance of the semiconductor manufacturing facility.

In horizontal quartz tube cleaning stations, the tube is inserted into the cleaning enclosure and cleaned with an acid spray. The acid dissolves and removes the contaminant from the high-temperature furnace. A subsequent rinse cycle removes all traces of the acid from the tube surfaces. A drying cycle can speed up drying without introducing particles into the cleaning enclosure. Mechanical handling of the tubes reduces the possibility of breakage due to human error and minimizes opportunities for the entry of contaminating particles. Safety interlocks, exhaust fans and safety shields protect operators from the hazardous chemicals.

Modutek’s Quartz Tube Stations Offer Numerous Benefits

A key factor in effective customization of quartz tube cleaning stations is that the supplier has to design and build the stations so that they can make the required adjustments. Modutek designs and builds all process, etching and cleaning components in house at the company’s San Jose, California facility. Equipment is customized exactly according to the requirements of the specific application.

In addition to providing customized equipment, Modutek can supply the degree of automation required by the customer. Cleaning process steps can be initiated manually or the whole cycle can be completely automated. Different steps can initially be run and timed manually and then, when optimum performance is reached, automated operation can be locked in.

Full automation reduces human error and keeps operators safe by allowing them to monitor the cleaning process remotely. Automated quartz tube cleaning stations will run the same cleaning job exactly the same way, with identical timing and dosages. Results from an automated system are predictable and uniform and the system can be programmed for the best possible results.

Modutek’s horizontal quartz tube cleaning stations are an excellent solution for semiconductor manufacturers. Rugged and reliable with one-piece construction up to ten feet long, the basic units offer many options for additional features. Once the requirements of the cleaning application are satisfied, Modutek can offer design add-ons such as holding tanks, automation features, a T/C sheath cleaner or a bottle washer. Modutek is a leading semiconductor equipment manufacturer that provides continuous product innovations and improvements along with the highest degree of customer service and support.

Reviewed and Approved by Douglas Wagner
President & CEO, Modutek Corporation

The Benefits of Using Modutek’s Quartz Tube Cleaning Stations

The semiconductor wafer is the substructure on which the circuitry of every computer chip is laid down. Semiconductor wafers are fabricated in high-tech foundries, and require a precise, ultra-clean operation. One of the most basic requirements of a semiconductor wafer operation: reliably clean quartz tubes. Quartz tube cleaning stations are required equipment at every semiconductor foundry.

Most have several units stationed at different parts of the manufacturing process, each one specifically tuned and adjusted to the requirements of specific applications. Since the quartz tube cleaning process requires the use of corrosive chemicals, it takes an involved manufacturer and installer of quartz tube cleaning stations to design and install custom units for specific client needs.

How do quartz tube cleaning stations help?

Quartz tubes being delicate articles, cleaning them can be risk-prone. The ideal quartz tube cleaning process, therefore, minimizes human handling at every stage. This is the reason automated quartz tube cleaning stations are essential at any semiconductor wafer foundry.

With Modutek’s quartz tube cleaning stations, the handling of tubes during the cleaning process is mostly avoided — cleaning stations are designed to keep quartz tubes in motion while they are etched, and powerful nozzles direct water spray at the quartz tubes to maximize coverage Custom-designed cleaning stations come with many other options that can be applied to specific needs. Automated processes and nitrogen-drying can help in specific parts of the manufacturing process, for instance.

What do quartz tube cleaning stations look like?

The quartz tube cleaning stations designed and fabricated by Modutek are built out of white polypropylene. The cleaning processes are controlled by systems that can be turned to manual or automated mode, and units can be customized to specific height levels to perfectly fit the processes to which they are to be applied. Workers at these stations are protected from the acid cycle with PVC safety shields, and other standard features include hand-sprayers for deionized water, and Teflon guns for nitrogen use.

Clients are presented with a wide array of choices comes to customization. The station can be constructed out of FM 4910, or can include a hot nitrogen drying process as needed, for example. The right kind of holding tanks, automated bottle washers and other features can be designed and applied where necessary, and quality certifications required by third parties are arranged for, as well.

Automation Where it’s Needed

Modutek’s quartz tube cleaning stations can be designed and customized with optional automation for process lines that need it. From automated program recipes to tube roller systems, every part of the process can be made more efficient with automation. The operator merely monitors and controls the process through information presented on a screen, and can control various functions remotely. From bottle washing to drying, every part of the process is remotely monitored.

Automated processes do not actually require operator intervention. Processes, once they are set off, can go through to completion without operator input. Manual functions, when they are necessary in certain processes, can be remotely controlled at any point.

A process design that is set up to help the operator test different cycle times, is one of the most important parts of a properly designed automated system. Modutek offers a well-designed process to aid in testing. Once the right times are discovered, they can be locked in place to prevent accidental change

Modutek’s quartz tube cleaning stations, whether manual and automatic, are fully designed in-house. In-house design expertise helps ensure superior performance in any installation. With ultra-cleanliness being a basic requirement of the semiconductor fabrication process, customization to individual process needs is an absolute necessity for effective design. Modutek’s close control of the design of these appliances helps make it happen. Clients find Modutek’s complete, end-to-end support immensely helpful in the design of their lines. Whatever the application, Modutek has the expertise to evaluate, assess, design and deliver turnkey solutions.


Quartz Tube Cleaning Stations: What They Do and the Benefits They Provide

Quartz Tube Cleaning Stations: What They Do and the Benefits They ProvideQuartz tubes are used in the processing of semiconductor wafers at high temperatures inside a diffusion furnace and must be cleaned with corrosive chemicals. Quartz tube cleaning stations have to be customized for the requirements of a particular process. With expertise in chemical handling and the customization of chemical delivery stations, Modutek is ideally situated as both a designer and supplier of quartz tube cleaning stations that meet the needs of their customers. A rugged design combined with automation and drying options make the stations a reliable and flexible choice for quartz tube cleaning.

Benefits that Quartz Tube Cleaning Stations Provide

Quartz tubes are delicate and cleaning them is a critical process. Ideally semiconductor manufacturers need cleaning solutions that are effective while keeping the handling of the tubes to a minimum. With Modutek’s quartz tube cleaning stations the tubes roll during etch this helps reduce chemical usage. Spray nozzles and tubes are then used for DI water rising. The custom design includes options for automation and drying with nitrogen. Construction of the station can reach ten feet in length. In addition to quartz tube cleaning, possible applications include EPI tube cleaning, Poly Silicon tube cleaning, and bottle washing.


Standard Modutek quartz tube cleaning stations are of white polypropylene construction and have manual or automated roller systems. The station has casters and leg levelers and is constructed to the specific size and length needed for the particular application. All stations incorporate an acid cycle and a rinse cycle. PVC safety shields, a Teflon nitrogen gun and a deionized water hand sprayers are standard features.

Options include changing the construction material to FM4910 material and adding a hot nitrogen drying system. Once the basic application features are determined, options such as holding tanks, on board bottle washer automation can be added. Third party certifications are available. Modutek will evaluate each option for the appropriate application and make corresponding recommendations.


Optional automation features include an automated tube roller system and automated program recipes. From the main screen, the operator can see the status of the system and select operations. Options such as drying and bottle washing are integrated into the automation system and can be controlled from there.

When selecting automatic operation, no further control action by the operator is required. When selecting manual operation, an additional screen will come up showing the controls and allowing the operator to carry out the necessary actions. Safety interlocks remain active and the operator can return to the main screen at any time.

The setup section of the automatic system allows authorized personnel to program system parameters such as acid soak time, rinse time and dry time. A maintenance section allows an operator access and test different parts of the system. Access codes for setup, operation and maintenance can be set to ensure only authorized personnel use the different parts of the system.

Both the manual and automated version of Modutek’s quartz tube cleaning stations offer superior performance, reducing product defects due to process impurities during semiconductor manufacturing. The self-contained but customized and flexible nature of the stations allow for easy installation and service. All stations are designed and built in house by Modutek, allowing the company to offer a complete spectrum of support. If you need help selecting a quartz tube cleaning station for your specific application or want a quote, contact Modutek at 866-803-1533 or email [email protected].