Applying reactive ion beam etching (RIBE) processes at the Leibniz Institute of Surface Modification (IOM), several reference samples to be used in industry for calibrating of roughness testing equipment have been generated with the smoothest sample featuring 0.1 nm rms Sq. Subsequently these reference samples have been measured cross-site applying atomic force microscopy (AFM), white light interferometry (WLI), Nomarski1 microscopy (NM) and scatterometry (iTIRM2) determining the appropriate range of measurable rms surface roughness for each industrial measuring device.
Top hat diffraction efficiency in an all-dielectric SiO2/HfO2 grating femtosecond pulse compression grating is demonstrated with a close to 100% flat top over more than 20 nm around 800 nm wavelength. New perspectives are open for high average power femtosecond laser machining.
Synchrotron Radiation (SR) mirrors are ultra precision optical components with very high requirements to shape accuracy and smoothness. According to the special functions mirrors with different shapes are used. The dimensions of such mirrors extend from some tenfold of millimetres to a length of more than one meter. Commonly such mirrors are made of single crystal silicon, Zerodur(R), ULE(R) glass and in rare cases of silicon carbide, special steel or Glidcop(R). Some considerations lead to the result that also tungsten is an interesting alternative material for SR-mirrors. The paper presents the design, some results of the ultra precision machining and some functional parameters of the SR-mirror prototype.
The performance of x-ray beamlines at 3rd generation synchrotron radiation sources and Free Electron Lasers (FELs) is limited by the quality of the state of the art optical elements. Proposed FEL beamlines require optical components which are of better quality than is available from the optical manufacturing technology of today. As a result of a joint research project (Nanometer Optik Komponenten - NOK) coordinated by BESSY, involving both metrologists and manufacturers it is possible now to manufacture optical components beyond the former limit of 0.1 arcsec rms slope error [1, 2]. To achieve the surface finishing of optical components with a slope error in the range of 0.04 arcsec rms (for flat or spherical surfaces up to 300 mm in length) by polishing and finally by ion beam figuring technology it is essential that the optical surface be mapped and the mapping data used as input for the multiple ion beam figuring stages. Metrology tools of at least five times superior accuracy to that required of the component have been developed in the course of the project. The Nanometer Optical Component measuring Machine (NOM) was developed at BESSY for line and area measurements of the figure of optical components used at grazing incidence in synchrotron radiation beamlines. Surfaces up to 730 cm2 have been measured with the NOM a measuring uncertainty in the range of 0.01 arcsec rms and a correspondingly high reproducibility [3]. Three dimensional measurements were used to correct polishing errors some nanometers high and only millimeters in lateral size by ion beam treatment. The design of the NOM, measurement results and results of NOM supported surface finishing by ion beam figuring will be discussed in detail. The improvement of beamline performance by the use of such high quality optical elements is demonstrated.
Acoustic Micro Imaging (AMI) has long been established as a method of NDT of the wafer-to-wafer bonding quality in directly bonded wafers. In conventional imaging systems a C-Mode Scanning Acoustic Microscope operating in reflection is utilized. In this paper a non-confocally adjusted Phase Sensitive Acoustic Microscope (PSAM) operating in transmission at a frequency of 85 MHz is employed for imaging. This mode of operation results in a time-dependent point spread function, which together with full-transient data acquisition allows for its optimization in terms of resolution in the post-processing stage. Furthermore, the information contained in the images produced by varying time-dependent PSF is used for identification of bonding defects in directly bonded wafers. Both completely disbanded and weak bond regions in the wafer-to-wafer interface are identified. These latter areas are present, e.g. at the rim of the entirely disbanded regions as an intermediate interface condition between fully bonded and completely disbanded states. Mode conversion of the ultrasound waves at the solid-solid and solid-liquid wafer boundaries has been exploited to excite shear waves that are sensitive to weak bonds. A short burst transducer excitation and time-selective post-processing of the acquired data is employed to prevent overlap with the direct transmission signal or its echo sequences and in this way making visible the amplitude variation induced by the interface bond degradation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.