Happy reading.

A recent article in JMM attempts to quantify just this effect, that the impact of LER is not constant with constant variance. One must instead specify the PSD at least to the level of the three parameters: variance, correlation length, and roughness exponent.

In these instruments, femtosecond laser pulses create local changes in the refractive index of the photomask substrate (in the case of CDU correction) or bulk strain (in the case of registration error correction). Zeiss claims correction of up to 50% of the total placement error contribution of the photomask.

Zeiss also claims that the treated photomasks are stable. Privately they claim that there is no induced flare. One wonders how this is possible after introducing millions of small pockets of color centers and high strain throughout the exposure field.

Further reading:
doi:10.1117/12.896910

doi:10.1117/12.899904

doi:10.1117/12.879885

[Sorry - I neglected to "Publish" this one last fall. - Richard L]

Fig. 1 Previous REBL stage concept.

Entire wafer areas can be covered by moving the stage along one axis in addition to rotating. However, throughput was found to be inadequate, necessitating the addition of more column clusters. Unfortunately, with more clusters arrayed around the circle, one cannot cover the wafer areas by a simple one-dimensional stage motion. Instead, one must move each column cluster in and out radially. This is clearly not possible mechanically.

Fig. 2 New REBL stage concept.

K-T’s latest proposal shows two X/Y maglev stages moving side by side in opposing directions. Each stage carries multiple wafers. (See Figure 2.) Obviously, this configuration suffers stage turn-around overhead. Because K-T targets the 16 nm node, and expects a higher dose requirement, they claim that the overhead is negligible.

K-T claims to have “some” functional modulator chips, but clearly continues to have difficulties here. The next column design (Column 4) due this year will operate at 100 kV and will have 100X demagnification. K-T expects 5 nm to 12 nm beam blur. Throughput will be limited to a few wafers per hour. Importantly, K-T may be targeting the cut pattern market rather than fully general patterning.

The market window for EUV is rapidly closing. Intel is rumored to have locked down the processes all the way down to the 14-15 nm node. This means that the next available node for EUV insertion is 10-11 nm. If that node is missed as well, EUV at the current wavelength is a one generation technology. Since flare scales with the inverse square of wavelength, any wavelength reduction forces the surface roughness of the materials used for making mirrors and masks to far less than 1 nm 3σ for the flare to be held below 10%. I conclude that EUV may never be production worthy without an immediate step-function advance in source power.

• Geometrical and topological aspects of graphene and related materials  arXiv:1112.2054v1
• Graphene: junctions and STM spectra  arXiv:1111.6275v1
• Experimental review of graphene  arXiv:1110.6557v1
• Graphene synthesis and band gap opening  arXiv:1108.4141v1
• Thermal properties of graphene, carbon nanotubes and nanostructured carbon materials  arXiv:1106.3789v1
• Electronic properties of mesoscopic graphene structures: charge confinement and control of spin and charge transport  arXiv:1104.2183v1
• Electron-electron interactions in graphene: current status and perspectives  arXiv:1012.3484v1
• Graphene photonics and optoelectronics  arXiv:1006.4854v1
• Electronic properties of graphene in a strong magnetic field  arXiv:1004.3396v4
• Electronic transport in two dimensional graphene  arXiv:1003.4731v2
• Production, properties and potential of graphene  arXiv:1002.0370v1
• The electronic properties of graphene  arXiv:0709.1163v2

Happy reading!

The photonic wire bonds are manufactured by two-photon lithography in SU-8 resist. One can easily envision taking this technology into manufacturing. It should enable very high speed chip-chip communication.

For details, see arXiv:1111.0651v1.

When we speak of quantum mechanical systems, what usually comes to mind are optical, electrical, and magnetic phenomena associated with atoms, molecules or solids. Rarely do we think of mechanical systems per se.

The review discusses progress in cooling nanoscale mechanical systems to the ground state, and then measuring position and momentum. Remembering the peculiarities of quantum mechanics, it is evident that measuring location of such an object, for example, disturbs the very location being measured. Nevertheless, the ground state motion of nanomechanical systems has been observed.

Interesting reading.

Highlights:

NuFlare announced specifications for the EBM-8000 mask writer, targeting the 22 nm node. They have coaxed the lanthanum hexaboride source up to a current density of 400 A/cm² and reduced the maximum flash size to 0.35 micron. The field sizes are also reduced, the main field now being 180 microns and the sub-field 10 microns max. They anticipate achieving 2 nm overlay (sparse patterns).

IMS continues to meet their multi-beam development milestones. We were treated to linearity measurements over features from 24 nm to 90 nm (±0.5 nm). So they are able to do quite good multi-e-beam exposures with a fixed stage. The schedule calls for integrating the full sized (512 X 512) blanker array this month, a moving stage and data-path in December, and first mask printing in March 2012.

Lowlights:

In the 1980′s 1X X-ray was the “lithography of the future” and, as one wag put it, “always will be”. EUV looks increasingly like the “lithography of the future”. This conference we were asked to believe that the source vendors are going to leap from < 10W to > 100W by this time next year. I found no believers among the audience. Defects of all manner continue to bedevil mask blank production. It turns out that even a 2 nm bump (or dig) on the base silicon shows up as a defect to EUV radiation. Needless to say, any 2 nm anomaly in any of the 85 or so layers stacked on top also shows up as a defect. To cap it off, the V.P. of Rapid (K-T’s photomask inspection division) decidedly did not commit to fund an inspection tool at this time. (He also subtly hinted that such a tool would be frightfully expensive.)

Oddities:

The squeegee is back. Out of the Insitute for Microelectronics, Stuttgart comes news of an organic 6-bit DAC fabricated by stencil printing. A nice graphic can be found here.

Conference abstracts may be found here for a limited time.