MURA/CD Error High Resolution Visualizing System [WASAVI Series MR300]

Lasertec has commercialized [WASAVI Series MR300] that detects, with high-speed and high-resolution, MURA/CD Error defects generated in the manufacturing processes of semiconductor and image-sensor.

Nowadays, quest for ever finer design rules and introduction of newer processes result in the reduction of allowances in the device manufacturing processes, and requirements for quality control in each process is becoming more and more stringent. Under such circumstance, management of resist application process and controlling of CD after exposure/development are becoming very important tasks. The MR300 announced here by Lasertec visualizes the whole surface area of wafer with high-speed and high-resolution, which leads to detection of minutely small thickness unevenness of layer (MURA) and CD errors after exposure/development.

The conventional thickness measurement systems and CD-SEMs' require longer measurement time, and 100% inspection of wafers limits the number of measurement points under only several tens. Thus, it has been very difficult to monitor phenomena that occur locally within wafers. The MR300 detects, without using dummy wafers or specially designed test patterns, resist thickness unevenness, CD errors and pattern shape deformation that occur locally, by observing the whole area of production wafers by utilizing scattering, interference and reflection lights. In addition, the new system leads to comprehension of phenomena that have not been grasped thus far, because the new system acquires images of high resolution, which has not been possible with the conventional macro-type inspection systems.

Wafer processes now can be very speedily optimized even at its development and start-up stages, because the MR300 allows to comprehend the surface status of the wafer with adequacy and high-speed. In the mass production line, the new system implements improvement of process tool operation rate and of product yield, because defectives are immediately found due to the whole area observation of 100% wafers, which leads to prevention of accidental product deficiency.

• Detection of minute defective area by high-resolution visualization over the whole wafer area
• Detection of fine thickness unevenness with high sensitivity
• Detection of CD errors in the several-tens-nanometer range
• Acquisition of surface layer information regardless of any effect from substrate
• Fulfilling and easy-to-use display function, and sophisticated analysis function

• Inspection of thickness unevenness in the resist application process
• Inspection of CD errors and pattern shape deformation after exposure/development
• MURA/scratch inspection in the etching, CMP and layer formation processes