This paper demonstrates the improvement using the YieldStar S-1250D small spot, high-NA, after-etch overlay in-device measurements in a DRAM HVM environment. It will be demonstrated that In-device metrology (IDM) captures after-etch device fingerprints more accurately compared to the industry-standard CDSEM. Also, IDM measurements (acquiring both CD and overlay) can be executed significantly faster increasing the wafer sampling density that is possible within a realistic metrology budget. The improvements to both speed and accuracy open the possibility of extended modeling and correction capabilities for control. The proof-book data of this paper shows a 36% improvement of device overlay after switching to control in a DRAM HVM environment using indevice metrology.
Reversible watermarking is a technique for embedding data in a digital host signal
in such a manner that the original host signal can be restored in a bit-exact
manner in the restoration process. In this paper, we present a general framework
for reversible watermarking in multi-media signals. A mapping function, which
is in general neither injective nor surjective, is used to map the input signal
to a perceptually equivalent output signal. The resulting unused sample values of
the output signal are used to encode additional (watermark) information and
At the 2003 SPIE conference, examples of this technique applied to digital audio
were presented. In this paper we concentrate on color and gray-scale images.
A particular challenge in this context is not only the optimization of rate-distortion,
but also the measure of perceptual quality (i.e. the distortion). In literature
distortion is often expressed in terms of PSNR, making comparison among different
techniques relatively straightforward. We show that our general framework for
reversible watermarking applies to digital images and that results can be presented
in terms of PSNR rate-distortions. However, the framework allows for more subtle
signal manipulations that are not easily expressed in terms of PSNR distortion.
These changes involve manipulations of contrast and/or saturation.
A digital watermark can be seen as an information channel, which is hidden in a cover signal. It is usually designed to be imperceptible to human observers. Although imperceptibility is often achieved, the inherent modification of the cover signal may be viewed as a potential disadvantage. In this paper, we present a reversible watermarking technique for digital audio signals. In our context reversibility refers to the ability to restore the original input signal in the watermark detector. In summary, the approach works as follows. In the encoder, the dynamic range of the input signal is limited (i.e. it is compressed), and part of the unused bits is deployed for encoding the watermark bits. Another part of these bits is used to convey information for the bit-exact reconstruction of the cover signal. It is the purpose of the watermark detector to extract the watermark and reconstruct the input signal by restoring the original dynamic range. In this study we extensively tested this new algorithm with a variety of settings using audio items with different characteristics. These experiments showed that for 16bit PCM audio, capacities close to 1-bit per sample can be achieved, while perceptual degradation of the watermarked signal remained acceptable.
The illegal copying of movies in the cinema is now common practice. Although the quality is fairly low, the economic impact of these illegal copies can be enormous. Philips' digital cinema watermarking scheme is designed for the upcoming digital cinema format and will assist content owners and distributors with tracing the origin of illegal copies. In this paper we consider this watermarking scheme in more detail. A characteristic of this watermarking scheme is that it only exploits the temporal axis to insert a watermark. It is therefore inherently robust to geometrical distortions, a necessity for surviving illegal copying by camcorder recording. Moreover, the scheme resists frame rate conversions resulting from a frame rate mismatch between the camcorder and the projector. The watermarking
scheme has been tested in a 'real' digital cinema environment with good results.