Silicon MOS device structures for phosphorus donor qubits

We describe the integration of p-i-n structures for single-ion implant detection with p-type channel-stop regions to eliminate parasitic leakage currents in n-MOS structures while maintaining a single-ion detection capability. The structures are configured for the assembly of a metal-oxide-semiconductor (MOS) spin-qubit architecture based on phosphorus donors in silicon. The detection method is based on charge collection in the sensitive region by generation of electron-hole pairs in the Si substrate following the impact of a single 14-keV P⁺ ion. We present the results of leakage current and ion-beam-induced-charge collection (IBIC) tests which show that the structure is capable of providing almost 100% detection efficiency for implanted P ions, thus facilitating the construction of Si:P qubit devices.