Monthly Archives: November 2015

Improvements to the Silicon Wet Etching Process

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Improvements to the Silicon Wet Etching ProcessAs a result of improvements to equipment design and materials,  silicon wet etching process controls have improved to produce higher wafer yields with reduced defects. Modutek provides silicon wet etching equipment engineered to incorporate such improvements that are designed for reliability, safety, and low cost of ownership. The wet etching products from Modutek include features that offer specific advantages and deliver improved results. Process engineers and fabrication facility managers can order customized equipment to meet their needs and to ensure they receive the process improvements they expect.

Modutek’s QFa Series High-Temperature Recirculating Quartz Baths and the Qa Series Constant Temperature Quartz Baths are designed to set the quality standard in quartz baths. Used for etching, stripping, and heating, the baths feature fast, even heating to improve process yield and minimize damage from runaway temperatures. The high-quality internally flame-polished virgin fused quartz process vessels reduce downtime and increase reliability due to longer vessel life.

Although Modutek’s Teflon tanks come in standard carrier sizes, the company will build custom sizes to match any requirement. Tank configurations are Temperature Controlled Recirculating Baths, Temperature Controlled Static Baths and Teflon Ambient Baths. Inline heating or immersion heating are available. Modutek can help design the optimal configuration for both new as well as existing systems you may already have.

Modutek’s silicon wet etching baths deliver excellent process control while retaining flexibility in installation and operation. The control system monitors the temperature of the bath to determine when adding de-ionized water is required to maintain the acid-to-water ratio. As water is lost to evaporation, the boiling point of the bath increases and the control system adds small amounts of water to the boiling liquid, ensuring that the water mixes in immediately. This method tightly controls the boiling of the chemicals and avoids “bumping.” The availability of remote metering means that the product is easy to install and Modutek can help find the best solution for any process station.

Modutek’s line of Quick Dump Rinsers can increase process efficiency by reducing rinse times and DI water consumption. The Rinsers feature state-of-the-art engineering to eliminate particle entrapment and minimize rinsing times. Dual overhead spray manifolds, a contoured vessel design and a large machined dump door ensure efficient and rapid operation.

For facilities that could benefit from using KOH etching, Modutek offers customized solutions manufactured according to customer specifications. KOH etching is a repeatable process that delivers fast etching at a low cost. Modutek’s solutions use the company’s Teflon tanks with advanced welding techniques and all-PFA material. The products can be designed to particular specifications or to be compatible with your existing wet bench equipment. Once the wet etching process is established, continual adjustments are not necessary. Modutek can integrate the new products into an existing line to deliver process improvements and increased efficiency.

Making use of improved designs or higher-quality materials can generate substantial benefits from reduced costs and better throughput. The increased ability to manufacture customized products that are optimized for a particular application can further improve silicon wet etching results. For any questions about silicon wet etching products or for help selecting the right manufacturing equipment for your requirements, call Modutek at 866-803-1533.

Wet Processing Equipment Applications

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Wet Processing Equipment ApplicationsModutek provides a complete line of silicon processing solutions with state-of-the-art wet processing equipment designed to deliver high quality output at a low total cost of ownership. Applications include wafer etching, cleaning, drying, stripping and metal etching. Specific solutions include KOH etch and nitride etch. State-of-the-art design and engineering ensures that equipment is reliable, safe and low-maintenance.

The rotary wafer etching system can etch, clean, reclaim, develop and strip semiconductor wafers and substrates. It features a dual tank design with a transfer between tanks for etching and cleaning or rinsing. A carrier assembly holds the wafer boats and takes up to 50 six-inch or 25 eight-inch wafers at a time. When the operator closes the fume door and presses the start button, the carrier assembly carries out a continuous rotational agitation in the chemical tank for a pre-set time. The assembly then automatically transfers the wafers to the rinse tank in less than three seconds. After the Quench-Quick Dump-Overflow rinse cycles, the wafers can be moved to the drying unit.

The system can be programmed with up to five process recipes and a touch screen controller displays a summary of the recipe and the process. Axial rotation of the wafers at up to 80 rpm ensures adequate agitation for consistent results. The system is flexible enough to handle different semiconductor processing applications and can carry out automatic batch processing.

Modutek’s vacuum metal etcher is designed for precision etching of aluminum layers on semiconductor wafers. The fully automated unit etches aluminum in a vacuum to eliminate hydrogen bubbles that interfere with the etching and produce “snow” and bridging on the etched wafers. At the beginning of a cycle, the unit evacuates the plenum, drawing acid into the etch tank. Etching continues until the preset time is elapsed or the end-point detector senses that lines have been etched through the aluminum layer. When etching is complete, the acid drains back into the acid reservoir and nozzles spray deionized water over the wafers. The metal etcher is characterized by a fast throughput and a high yield.

Modutek’s IPA Vapor Dryer provides a way to clean dry wafers without water spots. The unit can introduce ozone into the drying chamber to eliminate organic impurities. Most drying cycles take only 10 to 15 minutes. As low-cost drying solution, Modutek can custom design their IPA vapor dryers to meet your specific requirements and application.

In addition to equipment that can be used for a variety of semiconductor processing, Modutek offers specific solutions such as KOH etching and nitride etching. For KOH etching, Modutek uses an individualized approach that produces solutions for specific customer applications with the company’s Teflon tanks. The tanks are all-PFA material and sheets are welded using advanced techniques designed to reduce impurities. Modutek KOH etching solutions are designed to work with a customer’s existing wet bench equipment.

For nitride etching, Modutek provides a new Nb series Silicon Nitride Etch Bath. The system features a dual system that monitors the chemical boiling while ensuring tight control of the nitride etching process. As a result, the system provides unparalleled control of the nitride etch process and uniformity while achieving elevated levels of safety and reliability.

Modutek’s wet processing equipment is designed to meet the application needs of any semiconductor fabrication or research facility, either with standard products or with custom-designed solutions. Call Modutek at 866-803-1533 for any questions you have about wet processing equipment or if you need help in choosing the right equipment for your specific requirements.