Nanofabrication of multi-qubit solid state quantum computer device

Full text: In the solid state quantum computer (SSQC) design proposed by Kane, an array of phosphorous-31 atoms embedded in a silicon substrate provides the quantum bits. Quantum information is encoded on the nuclear spin of these 31P atoms and interaction between the qubits is mediated via the donor electrons in a controlled way by employing surface gate electrodes. A critical requirement of this design is the alignment of the underlying 31P array to these gates and the single electron transistors (SETs) that facilitate the qubit readout. We report a fabrication method for scalable multi-qubit devices that allows accurate registration of metal SET and gate structures to the 31P qubits in a self aligned process which incorporates electron beam patterning, ion implantation and multi-angle metal evaporation