In this thesis molecular Quantum Cellular Automata (QCA) is to be fabricated into a real device. The principle of this experiment is to detect the switching activity of molecules using a single electron transistor (SET). This is done by growing molecules on a highly doped p+ Si substrate called a P+ window. The P+ window is also a part of the island of the SET such that the molecules are capacitively coupled to the SET. The stateswitching in the molecules will cause an electrical potential change on the island which will affect the current flow, IDS, of the SET. The fabrication of the device mainly involves the following steps: The formation of the P+ window, the deposition of metal pads and wires, the growth of the SET, and the growth of molecules. Until now, real devices have been made but the switching activity of the molecules has yet to be detected.