Reducing Wafer Processing Time and Costs with a Wafer Etching System

Reducing Wafer Processing Time and Costs with a Wafer Etching SystemSemiconductor fabrication facilities and research centers can reduce wafer processing times and cut costs using Modutek’s rotary wafer etching system. The automated batch processor delivers chemical etching, stripping, cleaning and developing solutions for semiconductor wafers or substrates. The system features high precision, increased safety for operators and rapid processing in a compact design. It can increase throughput and process efficiency while maintaining or improving output quality.

Rotary Wafer Processing

Modutek’s Rotary Wafer Etching System is a wet bench with a dual tank design. The system’s carrier assembly takes the wafer boats into the chemical tank where it provides rotational agitation for a set time. The system then transfers the carrier assembly to the rinse tank for rinse cycles.

When chemical processing and rinsing is completed, the operator can place the carrier in the unload position and remove the wafer boats for drying. The system helps ensure consistency with its rotation of the wafers in the baths and with a rapid transfer from the chemical tank to the rinse tank.

Automatic Operation

Modutek’s wafer etching system features touch screen control and programmable recipes for fully automatic wafer processing. The automation system’s microprocessor can control up to five recipes that are programmed via the touch screen. The screen displays the recipe in use and process information.

When the operator starts the automatic process, the system takes control of the carrier and transfers it through the chemical and rinse cycles according to the programmed values. The rotation can be set at up to 80 rpm in a closed loop motor control for high precision. Process temperature can be controlled to plus/minus one half degree centigrade from ambient to 100 degrees. Process times, pre-rinse times and quick dump cycles can be set to between zero and 9999 seconds (166 minutes), and transfer from the chemical tank to the rinse tank takes less than 3 seconds.

System Features

Modutek’s Rotary Wafer Etching System is a compact, freestanding unit with a small footprint measuring 39 inches wide, 44 inches deep and with a 74-inch high back panel. It can accommodate multiple wafer sizes in one toll with a rotor change and it has a production capacity of up to 50 6-inch wafers or 25 8-inch wafers at a time.

The system features double containment construction and goes to fail-safe mode when N2 pressure loses electrical power. Two sensors monitor liquid levels and the system has over temperature protection. All parts of the system that are in contact with corrosive chemicals are made of inert plastic and Modutek can supply tanks and cabinets made from other material as an option.

Additional system options include the capability to handle larger wafer sizes, a chemical filtering and re-circulating system, a fume condenser, a gravity chemical fill system and a heating/cooling system in the process tank. The system can be fitted with an RTD sensor for temperature reading to 0.1 degrees centigrade and a resistivity monitoring system in the rinse tank is available, as are ultrasonic cleaning systems.

Modutek prioritizes the use of an economical and self-contained unit with an ergonomical design that offers a high level of safety for operators and improved process efficiency. The Model-SPS Rotary Wafer Etching System fulfills these goals and allows customers to update their systems with a proven solution offered by an experienced supplier. The available options increase flexibility and let customers match the system to the requirements of their application. When requirements are complicated or unclear, Modutek can help and propose solutions and options that meet the requirements of each customer.

Selecting the Right Equipment for Your Silicon Wet Etching Application

Selecting the Right Equipment for Your Silicon Wet Etching ApplicationSemiconductor manufacturing involves many process steps that require fabrication facilities to utilize the right processing equipment. Fabrication facilities need to choose a semiconductor equipment supplier that can provide a broad range of reliable products to support their applications, and also insure that the equipment to meets all requirements. Modutek has extensive experience and expertise in providing high quality equipment and a record of supplying reliable products for all silicon wet etching applications.  Below several products are discussed along with the specific wet etching applications that they support.

Quartz Baths
Quartz baths support a variety of etching, cleaning and stripping processes including SC1 cleaning, RCA clean and SPM clean. The Modutek bath designs have evolved over 30 years to become the quality standard in the industry. They are made of semiconductor grade, flame polished quartz and come in a range of sizes from inner lengths of 7.75 inches to 21.5 inches and heater power from 2 to 6 kW. The designs emphasize safety, reliability and cost of ownership.

Sub-ambient Systems
Modutek’s sub-ambient filtered etch baths are specifically designed for BOE (buffered oxide etch) and positive resist develop applications. They feature continuous filtration in the 10 to 0.2 micron range, reduced acid consumption and a low cost of ownership. They are made of natural polypropylene and polyvinyldilene fluoride (P.V.D.F), offer a 10 to 60 degree centigrade range of operation and plus/minus 1 degree temperature control. A range of options lets customers match the system to their requirements.

Temperature Controlled Circulators
The Modutek RCe Series of Temperature Controlled Recirculators are suitable for etching, plating and developing applications and constant temperature baths. The units feature a compact design and stainless steel fluid paths for a high level of safety and reliability. The standard heating capacity is 1500 W while cooling capacity is one quarter horse power. Other heating and cooling sizes are available.

Teflon Tanks
Teflon tanks by Modutek feature a modular design that is easy to integrate into new silicon wet etching stations or incorporate into existing stations. Available configurations are temperature controlled recirculating baths, temperature controlled static baths and Teflon ambient baths. Heat sources can be Teflon inline heating or immersion heating in the overflow weir. The tanks are available in standard carrier sizes for single or double capacity and they support KOH Etching and TMAH applications.

Nitride Etch Baths
Modutek nitride etch baths are designed for unparalleled process control with an emphasis on safe operation. Modutek has designed a two-tier control system that monitors the temperature while maintaining the acid to water ratio by adding de-ionized water as required. The resulting chemical boiling achieves tight temperature control and avoids bumping. A remote metering system facilitates installation in new or existing stations.

Quick Dump Rinsers
The quick dump rinsers offered by Modutek provide efficient process rinsing without particle entrapment and reduced use of de-ionized water. They provide consistent rinsing with bottom filling, well-located D.I water spray nozzles and N2 agitation. A bottom filling option that creates a vortex agitation in the rinse tank is optional.

Solvent Baths
Modutek solvent baths are electropolished stainless steel tanks suitable for all solvent applications including IPA, acetone and resist strippers. The baths meet Class 1 Div 1 Group D requirements over an operating range of 30 to 100 degrees centigrade and the heat up rate is up to 2 degrees centigrade per minute, depending on the system size. Bath design is flexible and Modutek can help customers ensure the bath selected fits into their new or existing installation.

Modutek has over 35 years of continuous operating experience in developing and supplying silicon wet etching equipment. This experience results in a flexible approach and an unmatched range of semiconductor manufacturing equipment options. Modutek can supply the right equipment for a customer’s particular application and can help ensure that the selected equipment meets the customer’s needs. Call for a free quote and recommendations on using the right equipment for your silicon wet etching application.