AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Real-time and On-line Screening Method for Outgassing-materials Using Soft X-ray
CHANG HYUK KIM, Young Tae Sul, David Y. H. Pui, University of Minnesota
Abstract Number: 38 Working Group: Instrumentation and Methods
Abstract In the semiconductor industry, avoiding particles is critical to enhancing the production yield of semiconductor chips. Therefore, most particulate contaminations have been eliminated by filtration systems. In spite of these efforts, as shorter wavelength ultraviolet (UV) light sources are used in photolithography to increase the number of semiconductor chips in a single wafer, the semiconductor industry has encountered new contamination problems from airborne molecular contaminations (AMCs). Even though the concentration of AMCs in the cleanroom air is very low, down to ppb or ppt, they can destroy semiconductor chips by producing particles and haze under the UV irradiation, thus increasing manufacturing costs. AMCs can originate from everywhere and outgassing from construction materials such as adhesives is an good example. However, a famous method to evaluate outgassing-materials, thermal desorption gas chromatography mass spectroscopy (TD-GC-MS), is time-consuming and not suitable for frequent measurements of outgassing.
The objectives of this study were to develop a fast screening method for outgassing-materials and to apply this method for evaluating materials. For the screening method, an outgassing chamber was made of stainless steel, which can be heated up to 200 °C. Outgassing from materials in the chamber was carried by nitrogen gas into the soft X-ray conversion chamber and converted into particles assisted by soft X-ray. Size distributions of generated particles were measured by a scanning mobility particle sizer (SMPS). Particle number and volume concentrations were obtained from the measured size distributions. This method showed good repeatability at different conditions such as mass, residence time, detection range, temperature and relative humidity. Different adhesives will be further evaluated at the same condition using this method and compared to find low outgassing-materials. By this method, time for screening materials can be saved and used to evaluate the low outgassing materials in detail combined with TD-GC-MS.