The development of the Final Focus Metrology (FFM) system for beam metrology is in fact now entering its fourth generation of development, and while this is a niche area within HENSOLDT’s broad portfolio, the company is able to draw on a broad range of experience to apply to this challenging industrial application.

Looking at HENSOLDT's product families, the company takes care of a very wide range of wavelengths, and since they are used all over the product portfolio, this expertise can then be adapted for other requirements.

HENSOLDT’s heritage and knowledge of opto-mechanical design – including a combination of high precision optics, and very precise and stable mounting concepts – is also what is driving this application.

This is therefore a success story of how HENSOLDT’s vast experience in optronics solutions has led it to diversify and become the preferred supplier to one of the world leaders in semiconductor photolithography system manufacture.

What is a semiconductor device and where does the FFM fit in?

Semiconductor devices are a key component of many electronics, and anything digitised depends on a variation of them to provide circuity. It has been well reported in recent years that an exponential surge in demand for digital devices has led to a shortage in this semiconductor technology, but while the demand has evidently increased, investment is still being made in its advancement to ensure it meets future challenges. 

Trends for semiconductor technology includes a reduction in the already low size, weight and power (SWaP) of the devices, as well as making them faster and more sustainable. HENSOLDT’s customer is a leading developer of semiconductor technology, specifically extreme ultraviolet – or EUV - lithography systems that use light to print patterns onto the semiconducting silicon wafers which are the base material for any semiconductor device.

Within the EUV-lithography system, FFM plays a key role in the light source that emits the EUV-light. The function of FFM in the light source is to provide the customer with critical beam parameters and real time positional information of the drive laser.

The FFM toolset is therefore essential for controlling the creation of a particular type of radiation that is needed in the lithographic production process of the latest generation of microprocessors.

Next generation production

In its fourth generation that is currently in development, fundamental changes have been made due to the fact that the sensing capabilities needed to be broadend.

“FFM is now also partially in the high power beam path of the customer’s system which brings it’s own challenges. Beside the required low power optics used to condition the transmitted light for metrology, high power optics are incorporated now that are used to sample a small fraction of the highly energetic light emitted by the laser source.”

Arthur Fried, Project Manager Industrial Commercial Solutions at HENSOLDT Optronics

In total, several wavefront sensors and position sensing modules are planned for the system. The whole system has to be intrinsically thermally stable, and there is a very broad range of specifications that needs to be met. The fourth generation FFM is currently in the preliminary design phase, the optical layout phase of which has been passed, which is a major milestone of the development. HENSOLDT plans to have the first prototype developed by the beginning of Q2 in 2023, and in general, the development will take approximately 2.5 years.

In order to meet the demands of this program, HENSOLDT overhauled the cleanroom fabrication in Oberkochen, Germany in 2020, which not only enabled it to meet the demanding quality standards of the semiconductor industry, but also made it possible to double production at this facility.

The demand is high, and because semiconductor devices are critical components of many electronic devices, there’s a constant push to make them smaller, more efficient and more powerful. This creates challenges in the design and manufacturing process that HENSOLDT is accustomed to responding to across its customer base.

So while development of the FFM is very demanding, exacting production and manufacturing requirements are not new to HENSOLDT, and it is well prepared to meet the needs of this flourishing industry.