METAL(COSI2)/INSULATOR(CAF2) RESONANT-TUNNELING DIODE

Negative differential resistance (NDR) of nanometer-thick triple-barrier metal(CoSi2)/insulator(CaF2) resonant tunneling diode (RTD) and the structure dependence of its characteristics are demonstrated. The device consists of metal-insulator (M-I) heterostructures with two metallic (CoSi2) quantum wells and three insulator (CaF2) barriers grown on an n-Si(lll) substrate. A typical peak-to-valley current ratio (P/V ratio) obtained at 77 K was 2-3 and the largest P/V ratio was 25. A P/V ratio as high as 2 was obtained at 300 K. M-I RTDs with two quantum wells of various thicknesses were fabricated in order to investigate the dependence of resonance voltage on the thickness of the two quantum wells. Reasonable agreement was obtained between theory and experiment for this dependence.