Negative differential resistance of CaF₂/Si double barrier resonant tunneling diodes fabricated using plasma etching mesa isolation process

Abstract

We demonstrated the negative differential resistance (NDR) characteristics in CaF 2 /Si double barrier resonant tunneling diodes (DBRTDs) which have mesa structure isolated by the plasma etching process using CF 4 /O 2 plasma. Clear NDR characteristics with a peak to valley current ratio of 79 and a current density of 1-10 kA cm −2 was obtained from a CaF 2 /Si DBRTD mesa-isolated using CF 4 /O 2 plasma etching at room temperature. Furthermore, any degradation of performance of the DBRTD caused by dry etching has not been observed. The NDR characteristics were reasonably reproduced by theoretical analysis based on a ballistic transport model. These results implied that the plasma etching process using CF 4 /O 2 enables CaF 2 /Si heterostructure devices to be implemented into the Si-based integrated circuit technology.

Near-infrared (λ ∼ 1.2 μm) intersubband electroluminescence in Si/CaF2 quantum cascade structures

“…MBE was conducted to grow crystals. [31][32][33][34] Since it has been reported that the crystal growth of Si/CaF 2 thin films at around 80 °C suppresses the island growth of CaF 2 and improves planarity, crystal growth at around 80 °C was carried out for the i-Si and CaF 2 multilayer structure in this study. For CaF 2 deposition, ionization cluster beam deposition was carried out to improve the crystallity.…”