Ca F 2 ∕ Si ∕ Ca F 2 resonant tunneling diodes grown by B surfactant-mediated epitaxy

Abstract

A special solid-phase epitaxy technique utilizing the surfactant B for the growth of crystalline Si-QWs on CaF2∕Si(111) enabled us to grow CaF2∕Si∕CaF2 double-barrier diodes exhibiting resonant tunneling effects from 77K up to room temperature with peak voltages at 0.2eV, which is very close to simple resonant tunneling model predictions. The peak voltages and currents were virtually independent of temperature. No trapping or hysteresis effects were found in the I–V characteristics which exhibited 2–7 orders of magnitude larger peak current densities than previously reported CaF2∕Si∕CaF2 RTDs.

Structural transitions and relaxation processes during the epitaxial growth of ultrathinCaF2films on Si(111)

“…7,8 The performance of these devices has been improved by special deposition techniques which reduce the dewetting of Si on CaF 2 films. 9,10 Other RTD structures use lattice matched CdF 2 as alternative material for the quantum well 11 while Si-based CdF 2 / CaF 2 intersubband quantum cascade structures are realized to obtain electroluminescence at room temperature. 12 Both electroluminescence and photoluminescence ͑PL͒ have been observed for Si-based MnF 2 / CaF 2 heterostructures, too.…”

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

“…One essential building block for nanoscale solid-state devices is electric potential sequences for realizing electronic functions such as electron injection, transport, and storage, which can be implemented using the energy band discontinuity at atomically abrupt heterointerfaces. A CaF 2 /Si heterostructure is an attractive candidate for application in Si-based integrated devices, such as RTDs [1][2][3][4] and transistor, coulomb blockade devices, resistance switching devices 5) because of the large conduction band discontinuity (ΔE C ∼ 2.3 eV) 6,7) at the heterointerface and the small lattice mismatch with silicon owing to the similar cubic-based crystalline structures. Owing to the large ΔE C and energy band gap (E g for CaF 2 is 12.1 eV 8,9) ), the leakage current is expected to be suppressed to a low level even at room temperature (RT).…”

Formation routes and structural details of the CaF1 layer on Si(111) from high-resolution noncontact atomic force microscopy data

“…Due to the small lattice mismatch of 0.6% at room temperature between silicon and the ionic material CaF 2 , the growth of CaF 2 particularly on (111) surfaces of silicon has early been identified as a promising system for insulatorsemiconductor devices, and has especially been studied in * Present address: Fachbereich Physik, Universität Osnabrück, Barbarastrasse 7, 49076 Osnabrück, Germany; prahe@uni-osnabrueck.de the context of resonant tunneling diodes [9][10][11]. Besides this application-oriented relevance, CaF 2 on Si(111) is of fundamental interest in understanding the growth and properties of heteroepitaxial systems and has consequently been intensively studied.…”