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

Negative differential resistance (NDR) of nanometer-thick triple-barri er metal(CoSi2)/insulator(CaF2) resonant tunneling diode (RTD) and the structure dependence of its characteristics are demonstrated. The dev ice consists of metal-insulator (M-I) heterostructures with two metall ic (CoSi2) quantum wells and three insulator (CaF2) barriers grown on an n-Si(lll) substrate. A typical peak-to-valley current ratio (P/V ra tio) 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 we lls of various thicknesses were fabricated in order to investigate the dependence of resonance voltage on the thickness of the two quantum w ells. Reasonable agreement was obtained between theory and experiment for this dependence.