Highly Stable Lasers for Scatterometry

Optical metrology in lithography

In strive for ever more capable electronics, advanced processes led to an increase in complicated 3D structures (i.e. FinFET and others). To keep manufacturing yield up it is of utmost importance to tightly control all processes, such as overlay and critical dimensions of the features. With feature sizes well below the wavelength of light (currently down to 7nm), optical metrology is facing many challenges.

High measurement accuracy

Scatterometry is a key process to measure the overlay error of different lithography steps and thus ensure high yield rates. The measurement accuracy of scatterometry is well below 1nm and suited to judge and correct for overlay imperfections.

Lasers for scatterometry measurements must be highly stable in their power output and extremely low noise. At the same time, a broad emission spectrum is helpful to prevent speckle effects. Of course, a high quality beam shape and stable beam pointing is a prerequisite, as with most measurement techniques.

This unique set of requirements is provided by TOPTICA's lasers that are superior to most other diode lasers on the market.

Best practice example Scatterometry

A leading player in the field of semicon metrology designed-in a set of multiple iBeam smart lasers spanning the range from 405nm to 785nm to perform cutting-edge overlay metrology. Key reason for choosing the TOPTICA’s iBeam smart was its unique FINE feature which enables ultra-low noise performance and thus increases the critical signal-to-noise ratio in the application scatterometry. TOPTICA’s profound expertise and professional care supported a perfect design-in using a customized iBeam configuration.

iBeam smart: High Performance Single Mode Diode Lasers for Maximum Performance 375nm – 1064nm

Driven by the ever-innovating photonics world TOPTICA has further broadened its iBeam smart portfolio, to address the multiple requests for novel wavelengths and of course more power.

A significant power upgrade up to 450mW in the 405nm - 460nm wavelength range, extraordinary 200mW at 647nm and 660nm, as well as more wavelength options in the near IR permits TOPTICA to serve even more industrial applications and research fields.

With cw or analog, digital, and mixed modulation operation, the iBeam smarts support a broad variety of applications in biophotonics, microscopy, semicon inspection, industrial manufacturing and homeland security. 

For any further information please consult our web page at: www.toptica.com/smart