How Robotics Have Revolutionized Semiconductor Manufacturing

The automation over the last 25 years of wet bench stations used for semiconductor manufacturing has resulted in more efficient production and an increase in output quality. When the handling and mixing of the chemicals, the handling of the silicon wafers and the timing of the process steps were carried out manually, mistakes could result in defective products. Semiconductor equipment manufacturers have developed automation that has resulted in improved yields and less waste.

Modutek has been on the forefront of developing robotics and process control software that allows fully automatic or semiautomatic processing of silicon wafers. In this way, the entire semiconductor manufacturing process is controlled accurately and reliably. Chemical quantities and process timing are precise, process parameters are reproducible, and material handling is safe. Contamination is reduced with robotic wafer handling. For all these reasons, adding robotics to a wet bench processing line is a cost-effective solution for better facility performance.

Modutek’s Leadership in Wet Bench Robotics

During the company’s history of making wet process equipment, Modutek has focused on the integration of the latest technology in-house and with its own team of specialists. Founded in 1980, Modutek manufactured components such as quartz heated baths, nitride etch baths and rinsing systems. In 2002, Modutek acquired Sysmax Inc. with its advanced automation technology and from there developed its own robotics.

Advances in robotics have allowed Modutek and other semiconductor equipment manufacturers to offer semi-automated and fully automated stations. These wet benches and chemical stations can control the whole semiconductor manufacturing process with no or limited operator intervention. Both fully automated and semi-automated stations produce excellent process uniformity with semi-automated stations and robotics available at a lower cost if full automation is not required.

A key Modutek advantage for this type of equipment is that all process control software and robotics are designed and assembled in-house. The team working in the company’s San Jose, California manufacturing facility carry out all development work for both the SolidWorks Simulation Professional and SolidWorks Flow Simulation software and for the associated robotics. All silicon wafer fabrication equipment is also tested in-house using de-ionized water. As a result, Modutek can offer unparalleled support and customization services.

Advantages and Benefits

The primary motivators for installing fully automated wafer fabrication equipment are to reduce costs and improve output quality. Elimination of human error and increased precision of chemical use means less waste and high-quality products.

Modutek’s SolidWorks Simulation Professional and SolidWorks Flow Simulation software can calculate correct dosages and track chemical usage. With tighter environmental regulations, efficient chemical use not only reduces costs directly but also makes environmental compliance easier and less costly. When the composition of chemical baths is tightly controlled, the etch rate or wafer cleaning is predictable and consistent.

Automatic chemical delivery is not only more reliable than a manual procedure – it is also safer. Spills of hazardous or corrosive chemicals are less likely, and employee safety is increased.

Robotic handling of wafers can reduce contamination and deliver cleaner wafers for subsequent processing steps. The reduced size of features in semiconductor microstructures means that a single particle can block etching of a key feature or impact doping in a critical part of the semiconductor component. It is vital to keep contamination of wafers to a minimum, and robotic handling of wafers reduces the sources of particle contamination.

While some semiconductor manufacturing applications can be automated with standard solutions, in many cases the particular needs of a specific customer can require a degree of customization of the robotics and the process control software. Because Modutek does its own robotics and software design, developing custom applications is never a problem. Modutek’s team knows exactly how each part of the automated systems work and how to make the necessary adjustments.

With Modutek’s more than 35 years of experience, the company continues to promote innovation in robotics for semiconductor manufacturing. Robotics has made the wafer fabrication process more efficient, more predictable and safer. With its complete line of automated equipment, Modutek continues to bring these benefits to customers. For a free consultation or quote contact call 866-803-1533 or email Modutek@modutek.com.

How Megasonic Cleaners Improve Silicon Wafer Manufacturing

The cleaning of silicon wafers is one of the key process steps needed in semiconductor manufacturing. This as become even more critical as micro circuit geometrics continue to shrink on 300 mm silicon wafers. Sub micron particles must be removed from the wafer substrate without damaging the delicate microcircuit structures from previous process steps. Particles that remain may result in defective semiconductor components that don’t work or low quality devices that have sub-par performance.

Incorporating Megasonic cleaning technology in the wafer cleaning process effectively removes sub-micron particles and contaminants without damaging or altering the wafer surface. In order to clean effectively selecting the appropriate frequency and power level is important. Modutek has partnered with Kaijo Shibuya Corporation to incorporate their high frequency Megasonic cleaning systems directly into Modutek’s wet bench process equipment. The wet bench stations combine chemical cleaning processes such as RCA or SC1 with Megasonic cleaning in the megahertz range to remove particles and contaminants down to 0.1 microns. Depending on the cleaning temperature and duration, cleaning efficiencies of over 99 percent can be achieved.

How Megasonic Cleaning Technology Works

Megasonic cleaning systems use a high frequency generator to create high frequency sound waves through the use of a transducer that is immersed in a liquid filled cleaning tank. The compression waves that are generated from the sound create high pressure at their peaks and low pressure at their troughs. Small cavitation bubbles appear in the low-pressure troughs and collapse in the high-pressure peaks. The action of the bubbles in the liquid effectively removes contaminants and particles from the exposed surfaces.

Lower ultrasonic frequencies in the 20-100 kHz range produce relatively large energetic cavitation bubbles which can cause damage to delicate part surfaces. For applications associated with semiconductor cleaning, megasonic cleaning in the megahertz range is required since it generates much smaller energetic cavitation bubbles. The gentle cleaning action from bubbles at the megasonic frequency range will effectively clean without damaging the wafer surface.

The action of cavitation bubbles in the cleaning tank will also agitate the cleaning solution which reduces boundary layers and allows the cleaning solution access very small surface areas such as crevices and complex shapes. The use of megasonic cleaning in silicon wafer manufacturing improves the overall effectiveness of the chemical cleaning solution by removing small sub-micron particles through the action of energetic bubbles.

Modutek’s Use of Megasonic Cleaning

Modutek has used their partnership with Kaijo Corporation to continually improve the cleaning performance of their wet benches by using Kaijo’s Megasonic Cleaning technology. Kaijo is a world leader in megasonic and ultrasonic cleaning systems and Modutek incorporates the Quava megasonic cleaning system generator into their wet bench stations for this application.

The Megasonic cleaning system incorporated within Modutek’s wet bench station utilizes Kaijo’s standard megasonic generator which operates at 950 kHz. Frequency ranges of 200 kHz, 430 kHz, 750 kHz as well as 2 MHz are also available for cleaning applications that require a more or less robust cleaning action. There are three versions of Megasonic cleaning systems available which provide power levels of 600, 900 or 1200 Watts.

Modutek incorporates the use of Megasonic cleaning into their wet benches using either indirect or direct bath designs. Indirect Megasonic cleaning can operate at temperatures of up to 140 degrees centigrade while the direct design places a Teflon-coated transducer directly into the tank and can operate at temperatures up to 70 degrees centigrade. Both design options provide optimal sub micron particle removal without causing cavitation damage to the silicon wafers at the standard 950 kHz frequency.

Process engineers at semiconductor manufacturing fabs have effectively used Modutek’s wet benches stations that incorporate the use of megasonic cleaning to improve semiconductor device yields. The time needed for cleaning wafers is reduced while cleaning effectiveness is higher with less chemical consumption. The use of Megasonic technology has improved the removal of small sub-micron contaminants and has reduced wafer defects to produce better quality semiconductor devices. If you need to improve wafer manufacturing processes and device yields call Modutek for a free consultation or quote at 866-803-1533 or email Modutek@modutek.com.