Methods for patterning a semiconductor substrate using metalate salt ionic liquid crystals

A method to pattern a semiconductor substrate, the method comprising:

• producing a first pattern on an underlying layer of the semiconductor substrate, the first pattern comprising a plurality of features formed at a first pitch;
• depositing an ionic liquid crystal (ILC) solution within each feature of the plurality of features, wherein the ILC solution comprises metalate salt ionic liquid crystals (ILCs) having cation head groups, alkyl tail groups, and metalate anions, and wherein the metalate salt ILCs deposited within the plurality of features self- assemble into layered structures having alternating layers of head group layers and tail group layers, with the metalate anions segregated to the head group layers;
• exposing the semiconductor substrate to an oxidization process to remove the tail group layers from the layered structures and convert the head group layers of the layered structures into a metal oxide pattern having a second pitch, which is smaller than the first pitch;
• and
• transferring the metal oxide pattern to the underlying layer of the semiconductor substrate.