To improve the resolution and the sensitivity of optical metrology,
we have constructed an interferometer for vacuum-ultraviolet
wavelengths. To examine the influence of the wavelength, especially
with regard to the period of the object’s structure, we chose an
apochromatic design. With reflective optics, wavelengths from 157
to 900 nm can be employed for interferometric measurements. The
benefits and also the technological problems that accompany the use of
vacuum-ultraviolet wavelengths are discussed. The design of this
interferometer and measuring results with different wavelengths are
presented.

Ultraviolet interferometry with apochromatic reflection optics

Micro-optics is an indispensable key enabling technology (KET) for many applications today. The important role of
micro-optical components is based on three different motivations: miniaturization, high functionality and packaging
aspects. It is obvious that miniaturized systems require micro-optics for light focusing, light shaping and imaging. More
important for industrial applications is the high functionality of micro-optics that allows combining these different
functions in one element. In DUV Lithography Steppers and Scanners an extremely precise beam shaping of the Excimer
laser profile is required. High-precision diffractive optical elements are well suited for this task. For Wafer-Level
Cameras (WLC) and fiber optical systems the packaging aspects are more important. Wafer-Level Micro-Optics
technology allows manufacturing and packaging some thousands of sub-components in parallel. We report on the state
of the art in wafer-based manufacturing, testing and packaging.

Wafer-level micro-optics: trends in manufacturing, testing, and packaging

Improving the resolution of interference microscopes

An Evaluation of Thermal Deformation Behavior in Electronic Package Using UV Moire Interferometry

In recent years, moire interferometry method has been used extensively in the electronics industry to determine thermal strains caused by temperature changes in microelectronics devices The size of a flip-chip package has getting smaller To measure thermal deformations of these small flip-chips, instruments with much higher resolution are required Many researchers have tried to achieve this resolution enhancement of moire interferometry by using a phase-shifting method But the phase-shifting method has physical limitations Fundamentally to get higher resolution, the laser source should be changed In this article, we constructed a moire interferometry system by utilizing an ultraviolet laser (/spl lambda/=325nm) This UV system realizes higher resolution than He-Ne (/spl lambda/=633nm) system And we apply this system to evaluate thermal deformation in flip-chip package

Evaluation of thermal deformation behavior in electronic package using UV moire interferometry

The authors discuss the capabilities and problems of interference microscopy in the UV region. The motivation is obvious: as the dimensions in electronics, mechanics and optics become smaller and smaller, measuring principles are required which provide lateral resolutions in the sub- mu m and longitudinal resolutions in the nm range. Due to its limited resolution optics using visible light as to cede the field to scanning electron microscopy. However, if it were possible to enhance the resolution using UV light, optics has some advantageous features: parallel data acquisition with freedom from special preparation methods and, therefore, no destruction of the object. One can think of a two-step procedure to reduce the wavelength in interference microscopy by a factor of about 10.

http://iopscience.iop.org/article/10.1088/0963-9659/1/5/001/pdf

T Dresel

Papers

UV interferometry for microstructure measurements