The present disclosure provides a method for forming a thermoelectric device, comprising providing a semiconductor substrate and providing a first layer of an etching material adjacent to the semiconductor substrate. The etching material facilitates the etching of the semiconductor substrate upon exposure to an oxidizing agent and a chemical etchant. Next, a second layer of a semiconductor oxide is provided adjacent to the first layer, and the second layer is patterned to form a pattern of holes or wires. The second layer and first layer are then sequentially etched to expose portions of the semiconductor substrate. Exposed portions of the semiconductor substrate are then contacted with an oxidizing agent and a chemical etchant to transfer the pattern to the semiconductor substrate.