Gated Tunneling Structures with Buried Tungsten Grating Adjacent to Semiconductor Heterostructures

A tungsten (W) grating was fabricated and embedded in GaAs by MOVPE (metal organic vapor phase epitaxy) with the aim of realizing novel applications of ultrafine metal electrodes within semiconductor nanodevices. A combination of W grating and a semiconductor single heterobarrier was used to control the vertical current through the structure based on an effective barrier height modulation controlled by the Schottky depletion around the metal. Transistor operation was observed at room temperature and the mode of operation discussed. Moreover, a gated resonant tunneling transistor was demonstrated at 20 K by integrating GaInP/GaAs double barriers and W grating, including a 1.4 ×1.4 µm 2 opening window, to form a vertical channel. The peak-to-valley current ratios were modulated by the gate bias, and fine features due to the lateral potential constriction were observed directly in the current-voltage characteristics.