An integrated circuit structure includes: a field-effect transistor including a semiconductor region including a semiconductor material having a bandgap less than or equal to that of silicon, a semiconductor source and a semiconductor drain, the semiconductor region being between the semiconductor source and the semiconductor drain, a gate electrode, a gate dielectric between the semiconductor region and the gate electrode, a source contact adjacent to the semiconductor source, and a drain contact adjacent to the semiconductor drain; and a resistive switch or a capacitor electrically connected to the drain contact. One of the source contact and the drain contact includes a threshold switching region, to be a selector for the resistive switch or the capacitor. In some embodiments, the threshold switching region includes a threshold switching oxide or a threshold switching chalcogenide, and the resistive switch or the capacitor is part of a resistive memory cell or capacitive memory cell.