Monthly Archives: November 2017

Single Wafer Processing Spurs Demand for Wafer Cleaning Equipment

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Wafer cleaning equipment suppliers have to invest heavily in research and development to keep abreast of rapidly changing technologies and changing market conditions. Single wafer processing is one such change factor, spurring demand for wafer cleaning equipment and promising a rapid increase in market size. The wet process equipment supplier market is characterized by high barriers to entry since it requires substantial initial investment with high continuing costs. On the other hand, single wafer processing in mini-fab operations is very attractive due to flexibility and the speed with which a single wafer can be processed. As a result, the market may see additional entrants while existing suppliers try to keep up with the anticipated growth.

Wafer Cleaning Equipment Market Details

The global wafer cleaning equipment market size was about US $ 4 billion in 2016 and it is expected to grow to over US $ 7 billion by 2024. While semiconductor demand generally is fueling this growth, the use of single wafer processing is one of the factors that is behind the increasing demand for semiconductor cleaning equipment. Mini-fab facilities feature short cycle times and production lines that allow semiconductor manufacturers to quickly meet changing market conditions.

Single wafer processing uses ozonized water and hydrofluoric acid in single spin technology to reduce cycle times and increase output flexibility. As increasing numbers of operators jump into this segment of the semiconductor manufacturing industry, the demand for wafer cleaning equipment is skyrocketing.

Another factor in cleaning equipment market growth is the market for printed electronics. The technology creates electronic devices by printing on substrates and requires clean wafers as an input. Its primary advantage is low cost for high volume and the outputs are inexpensive, low-performance items such as RFID tags and smart labels.

The combination of single wafer processing and the high volume expected for printed electronics means that the almost doubling of market size over the next seven years is realistic. When electronic tags proliferate in transportation and retail and processors from single wafer mini-fabs become common in many industries that are not high users of electronics at present, the need for wafer cleaning equipment as an input for these market segments becomes clear.

Single Wafer Cleaning Techniques

Single wafer processing is only competitive when the cycle times for individual wafers are low and the output quality is at least comparable to wet batch processing. Single wafer spin processing can be used to etch silicon and provide a wet process for mini-fab single wafer cleaning. Spin processing can limit etching to one side of the wafer and can be used for wafer thinning. Single wafer cleaning is often carried out with megasonic cleaning because this method dislodges the tiniest particles and results in a low particle count for the finished substrate. As semiconductor manufacturers embrace single wafer processing, single wafer cleaning equipment is being brought out in the market.

Some single wafer processes are attractive because they deliver better results than traditional processes. Megasonic cleaning in particular can reduce particle counts for the smallest particles. The cleaning method uses megasonic sound waves in the cleaning solution to generate cavitation bubbles. When the bubbles collapse due to changing sound pressure they release energy that can free tiny particles from the substrate surface. Particle counts are often lower than with chemical cleaning methods.

Modutek’s Silicon Wafer Cleaning Equipment

Modutek has over 35 years of experience in providing the latest state-of-the-art silicon wafer cleaning and processing equipment. The company can help customers with advice on semiconductor manufacturing equipment and offers a complete line of wet processing systems. Modutek is ideally situated to benefit from the increased demand for silicon wafer cleaning equipment.

 

 

Advantages of HF-Last Etching and IPA Drying in One Chamber

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In the final stage of silicon wafer cleaning the silicon oxide layer has to be removed and the clean wafer dried without contamination. When wafers are removed from the HF etching process and transferred to a drying chamber, the extra handling increases the chances for wafers to pick up contaminating particles. Such particles cause errors in the further processing of the wafers and can result in final semiconductor products that are defective or of poor quality. Carrying out the final etching and the wafer drying in one chamber reduces the possibility of contamination and can result in better output quality. The latest field results from a customer using Modutek’s single chamber HF-last and IPA vapor dryer show a substantial reduction in particle counts on wafer substrates.

The Single Chamber Process

Modutek uses IPA vapor (Marangoni) drying in a free-standing unit with one drying chamber for DI water rinsing and drying. The IPA vapor is generated in a standard one gallon bottle and is introduced into the drying chamber through the top cover to ensure even distribution. IPA consumption is low but is still adequate to give surface tension drying across all wafers and substrates. The Marangoni drying technique results in wafers without any watermarks.

To allow single step etching and drying in one chamber, Modutek modified the IPA vapor dryer to include HF (hydrofluoric) acid injection before the start of the standard IPA vapor drying process. The HF acid injection is ratio controlled and provides an oxide etch down to bare silicon. Once etched, the wafers are rinsed to a controlled pH level. When the required pH level is reached, the IPA drying process begins without moving the wafers. The particle count on the wafers remains low.

Field Results

Modutek has supplied the new single chamber HF-last IPA dryer to customers and the first large scale results are now in. In the 0.3 to 5 micron range, fewer than 20 particles (adders) were added to the etched substrate after using the Modutek etching/drying combined system. These particle counts are substantially below those achieved using the previous process in this particular field trial. Semiconductor manufacturing facility managers and research center engineers can compare these results to particle counts resulting from their current process and may be able to achieve significant improvements using the Modutek equipment.

The number of microscopic particles on wafers is becoming more and more critical as micro-structures and electronic features become smaller. Where comparatively large conducting areas and physical structures can work well even when they contain a disruptive particle, particles in the way of smaller structures either result in defective semiconductor components or in components whose characteristics are not as specified.

Modutek’s single chamber technology lets semiconductor manufacturing facilities improve output performance and increase yield. The entire etching, rinsing and drying process took only about 15 to 20 minutes in this application. One customer is reviewing particle counts, yields and output quality throughout the entire operation because it is likely that the improved facility performance with the Modutek system can justify the cost of acquiring the new equipment.

How Modutek Can Help

Modutek has over 35 years of experience providing wet processing equipment to the semiconductor manufacturing industry. The company has the expertise to advise customers regarding their semiconductor processing needs and can customize their equipment to fit particular applications. Their state-of-the-art equipment has helped wet process facilities meet their production goals in the past and the new single chamber HF-last etch and IPA vapor dryer can now help customers improve overall production line performance and increase facility profitability.