Between process steps that etch silicon wafers and deposit circuit paths, semiconductor manufacturing relies on wafer cleaning to remove material from previous process steps and microscopic contaminating particles. As structures and circuits on wafers decrease in size, even the tiniest particles can interfere with etching and the creation of circuits and micro-structures.
Such interference can cause defects in the final semiconductor product, lower product performance or cause a reduced product lifespan. The use of Megasonic Cleaning results in a gentle cleaning action that dislodges particles from wafer surfaces while leaving the wafer, its circuits and structures undamaged. Megasonic Cleaning reduces chemical use and final product rejection rates using a process that is completely safe and environmentally friendly.
Megasonic Cleaning Delivers Quick Results with Safe, Gentle Cleaning Action
Megasonic cleaning systems generate microscopic cavitation bubbles in the cleaning solution. When a bubble bursts, it produces a tiny jet that dislodges contaminants from the surfaces of the parts to be cleaned. Lower ultrasonic frequencies generate comparatively large bubbles and powerful jets while high frequencies clean with smaller bubbles and less energetic jets.
The tiny structures etched into the silicon and the microscopic metal filaments deposited on the wafers are easily damaged. Products such as microprocessors, micro electro mechanical systems (MEMS), and controllers may not work properly if precise cleaning procedures are not followed. Using frequencies above 950 kHz in the megahertz range for cleaning the wafers ensures that the Megasonic Cleaning action takes place with the tiniest bubbles and the least energetic jets. As a result, Megasonic Cleaning is gentle enough to remove contaminating particles while leaving silicon surfaces, micro-structures and metallic deposits intact.
Reduced Use of Chemicals Saves Money
The traditional wafer cleaning process uses strong chemicals to strip contaminants and particles from wafer surfaces. In addition to the cost of purchasing the chemicals, there are costs for storage, handling and disposal. As environmental regulations become more strict, hazardous chemicals have to be stored in special containment facilities. Chemical delivery systems have to include special measures that guard against spills. Once the chemicals are used, they have to be neutralized and disposed of in a way that doesn’t harm the environment. All these measures are expensive and will become more costly as regulations tighten.
Workplace safety is another costly aspect of the use of hazardous chemicals. Operators have to be protected against inadvertent contact with corrosive materials and many of the chemicals emit dangerous vapors that require expensive ventilation equipment. Operators that work with hazardous chemicals need protective clothing that reduces productivity and work accidents can lead to serious injury.
Megasonic Cleaning removes contaminants from wafers and dislodges particles more effectively than chemical methods. The reduced use of chemicals saves money and leads to a safer, more productive workplace environment.
Modutek’s Megasonic Cleaning Improves Sub-Micron Particle Removal
Modutek has partnered with Kaijo Corporation, a world leader in megasonic and ultrasonic cleaning technology, bringing Megasonic Cleaning to wet bench semiconductor manufacturing. Modutek has integrated Megasonic Cleaners into the company’s wet bench equipment to produce unparalleled low particle counts. The bubbles of the Megasonic Cleaning system agitate the cleaning bath to disrupt boundary layers, allowing effective cleaning action around complex microscopic structures and inside holes. The tiny jets produced by the bursting bubbles break the bonds between the wafer surfaces and surface particles and allow the particles to be removed by cleaning solution currents.
The low particle counts achieved by Modutek’s wet bench stations incorporating Megasonic Cleaning reduce defects and improve yields for semiconductor manufacturing lines. Product quality rises while costs go down. Using the latest Modutek Megasonic Cleaning equipment improves overall facility performance for semiconductor manufacturing plants and research labs. Contact Modutek for a free consultation on selecting the right equipment to meet your manufacturing requirements.
