Wafer Inspection/Review System "M350H" Sales Release

Along with the pursuit for ever-finer design rule, the demand for higher quality silicon wafer is heightening stronger and stronger. However, at the same time, cost reduction is also the important issue and new processes for wafer production are being developed. There are cases that surface roughness at atomic level becomes an issue for wafers made by some new processes.
The conventional laser scattering type wafer defect inspection system demonstrates high sensitivity for wafers with good surface conditions, however, it is difficult for this type of inspection system to operate at high sensitivity on such wafers as epitaxial wafers and anneal wafers that have surface roughness at atomic level due to the effect of haze and it is always necessary to adjust the inspection sensitivity for each type of wafer. In contrast to the conventional scattering type defect inspection system, M350 that utilizes laser confocal system has capability to operate always at its highest sensitivity regardless of the wafer type and also has capability to verify the type of defect by reviewing detected defect images. For these features of M350, the system is currently used as the reference machine for wafer defect inspection.
However, the conventional M350 operates at 60 nm sensitivity that is not high enough for semiconductor devices with 90 nm design rule and onwards. M350H shows higher sensitivity of 50 nm while preserving the features of the conventional MAGICS systems and the features of this new M350H are listed below.

Difference of features between the laser scattering and the confocal type inspection systems

• The first defect inspection/review system that covers silicon wafers for semiconductor devices of 90 nm and below design rules, in the industry.
• Higher defect detection sensitivity is realized while preserving the same high throughput as that of M350. (Defect sensitivity of M350H is 50 nm as compared with 60 nm of M350)
• Because the system employs bright-field method, sensitivity for pits such as COP is higher than that of the laser scattering system.
• Laser confocal optics provides observation of not only 2 dimensional shape but also 3 dimensional shape of the detected defects.
• Image recognition provides automatic verification whether the detected defect is scratch or foreign particle.

• The system is applicable to wide variety of wafers such as mirror polish wafer, anneal wafer, epitaxial wafer and those wafers with additional layers such as SOI.
• Open cassette and FOSB can be installed and the system configuration can be chosen with flexibility.
• High Operationality

• High speed scan of 33 multi laser beams
• Utilization of laser confocal optics that realizes high resolution, no flare and high S/N ratio
• Employment of optics that possesses high resolution in vertical direction
• Employment of high powered Ar Laser as the light source
• The maximum image processing speed of 3.1 billion pixels per second is established by simultaneously driving 31 channels of high speed image processing circuits.

Inspection of silicon wafer

• Applicable to wide variety of wafers such as mirror polish wafer, anneal wafer, epitaxial wafer and those wafers with additional layers such as SOI
• In particular, laser confocal optics shows high sensitivity not only to foreign particles but also to shallow scratch and pit because the system simultaneously illuminates the wafer from various angles.
• This system is indispensable to technical development due to its capability of observing 3 dimensional defect shape with its high review function.
• This system can be applied to process development for gaining higher manufacturing yield by performing inspection after wafer cleansing and layer deposition in semiconductor device production line. The other application is for development of new materials.

Main body and a control unit