Distributed axis electron beam technology for maskless lithography and defect inspection

Abstract

The limitations to the throughput of electron beam systems employing a single axis are now well known. Accordingly there is increased activity in the exploration of multiaxis systems. The approach described here features both common focusing and common deflection, thus simplifying the problem of pattern stitching. Another feature, thought by some to be a disadvantage, is that the imaging is at unity magnification. We have designed and built a test stand that presently features one axis (or beamlet) in a large homogeneous magnetic field so that the extension to multiple axes can be seen to be straightforward. With this arrangement we have demonstrated that the resolution can be at least in the 30–50 nm range, that operation at low voltage (down to 260 V) is possible, that we can operate using multiple axes, and that secondary electrons generated by one beamlet can be confined so that it is possible to use this arrangement for high-speed inspection.

Review on Micro- and Nanolithography Techniques and their Applications

“…Therefore, these two techniques are normally used for fabricating prototypes of nanoscale structures and devices. To increase the system throughput, multiaxis electron beam lithography [26,27] has been proposed. So far, the deployment of this technique in manufacturing process is still limited due to the difficulty in developing practical electron beam sources [1].…”

“…The forms of masked lithography include photolithography [1][2][3][4][5][6][7][8][9][10], soft lithography [11][12][13], and nanoimprint lithography [14][15][16][17][18][19][20][21]. On the other hand, maskless lithography, such as electron beam lithography [22][23][24][25][26][27][28][29], focused ion beam lithography [30][31][32][33], and scanning probe lithography [34][35][36][37][38][39][40][41][42][43][44], fabricates arbitrary patterns by a serial writing without the use of masks. These techniques create patterns in a serial manner which allows an ultrahigh-resolution patterning of arbitrary shapes with a minimum feature size as small as a few nanometers.…”

Split-ball resonator as a three-dimensional analogue of planar split-rings

“…In comparison with standard FIB systems 41,42 that use gallium (Ga) ions, helium ion microscope (HIM) can provide significantly higher structuring resolution [43][44][45] . Also, in contrast to standard gallium-ion based FIB systems, HIM does not significantly dope the sidewalls of the materials during milling and thus may retain good plasmonic properties of the nanoparticles 41,46 . HIM images of two gold nanoparticles with cuts fabricated by this combined method are shown in Fig.…”

Carbon Nanotube Electron Sources: From Electron Beams to Energy Conversion and Optophononics

“…Although it is versatile and capable of extremely high patterning resolution, its usage is still limited in the semiconductor fabrication industry because of its low throughput, which primarily results from its "direct write" nature. Among the approaches to improve the performance of electron-beam lithography is the usage of shaped [201][202][203] and multiple [204][205][206][207][208][209][210][211] beams. For example, rather than using a focused beam with a nanoscale spot size to create an entire pattern point by point in a full-direct-right strategy, one may employ a wide beam shaped with various apertures to project large portions of the pattern with simple shapes such as rectangles and triangles.…”