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(a) Step 1: Polymer molecules are made to self assemble into perfect hexagonal arrangements. The sizes of the arrangement are set by the size of the polymer molecules. The dark circular areas are 20 nanometers in diameter and are spaced 40 nanometers apart.
(b) Step 2: IBM used the polymer material as a stencil to reproduce the nanoscale pattern in silicon dioxide, which is more rugged than the polymer and able to withstand higher temperatures. At this stage the polymer material is completely removed.
(c) Step 3: A combination of depositing silicon material and etching leaves silicon nanocrystals embedded within the 20 nanometer regions defined originally by the self assembled polymer.
(d) Dimensions of the hexagonal pattern of the initial polymer (dotted curve) are maintained throughout, as shown by the histogram of the final silicon nanocrystal dimensions (solid curve). The grey curve represents the dimensions of the hexagonal pattern at an intermediate process step.
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