With the continuous progress of Moore's law to the future semiconductor technology nodes - 11nm and 7Nm, the industry needs more advanced measurement tools - a more precise scale - which must be at least 10 times more precise than the current semiconductor measurement to achieve success, so as to promote the continuous progress of Moore's law.
Currently, the most precise measurement tool can reach 4nm precision. It is jointly developed by ABAM Technologies Inc.of California and Lawrence Berkeley National Lab (LBNL). They use electron beam lithography, atomic layer deposition and nano imprinting technology. In view of the continuous expansion of Moore's law to 7Nm in the new standard, Argonne National Laboratory (ANL) of the U.S. Department of energy has recently jointly developed the most precise measurement tool, the line spacing can be reduced to 1.5nm, together with ABEAM and LBNL.
1.5nm random test pattern (left) and scanning electron microscope (SEM) image (right)
The technology used in this design comes from the semiconductor industry; however, there is no time to discuss the details. However, this is not a typical CMOS manufacturing process. Because we need the contrast of materials to characterize and adjust the nano level measurement equipment, we use silicon crystal and tungsten silicide. However, the technology itself is not limited by the choice of materials, and a wide range of materials can be used, "said Sergey Babin, President of abeam technologies.
1.5nm random test patternThe microscope (TEM) image (left) and double close-up (right)
Use new materials as test patterns to calibrate and test measuring instruments for the manufacture of advanced semiconducting bodies. These test patterns include thousands of random lines with precise line width and can be used to measure the width of any relevant line route.
Researchers at aBeam Technologies, LBNL and ANL have also developed a technology that can produce test patterns with a line width as low as 1.5nm. Although the fabricated nanostructures seem to be random, it allows the nanometer-level measuring instrument to realize the modulation transfer function over the entire dynamic range, and characterize the most complete chip characteristics.
For the semiconductor industry, measurement tools are crucial because they provide feedback for the manufacturing process,” Babin pointed out. “Modulation transfer functions are widely used in optics, which also enables optical systems to break the diffraction limit. In nanometering In the field, a common problem is that there has been a lack of natural samples with known spatial frequencies, and our technology has bridged this gap. By creating virtual random test patterns with nanometer-level linewidths, nanometer-level measurement systems can More accurate characterization.
The test pattern itself is interleaved with silicon and tungsten silicide circuits in order to maximize contrast and provide it to the measurement system. The typical sample size is about 6x6 microns, with thousands of lines on each sample.
Our next step is to apply the fabricated test patterns to various measurement systems, such as scanning microscope, atomic force microscope, soft X-ray microscope, and develop a complete automated solution to characterize and adjust the system.