Hans Wallinga

Modeling of light-emission spectra measured on silicon nanometer-scale diode antifuses

Electroluminescence (EL) spectra of nanoscale diodes formed after gate-oxide breakdown of n+-polysilicon/oxide/p+-substrate metal–oxide–semiconductor capacitors were measured in reverse and forward bias. The nanoscale diodes, called diode antifuses, are created by the formation of a small link between the n+-poly and the p+-substrate with the properties of a diode. A previously published multimechanism model for avalanche emission from conventional silicon p–n junctions is applied to fit the EL spectra in reverse-biased silicon-diode antifuses. The results show that the light from reverse-biased diode antifuses is caused by the same phenomena as in conventional p–n junctions. Forward-bias spectra of the diode antifuses show different shapes when lightly or highly doped p substrates are used. In the case of a lightly doped p substrate, the EL intensity in the forward mode is increased by about two orders of magnitude in the visible-wavelength range with a maximum intensity in the infrared region. A phonon-assisted electron–hole recombination model is applied to fit the low-energy part of emitted spectra. The visible emission is attributed to the Fowler–Nordheim tunneling current through the SiO2, enabled presumably by electron capture into SiO2 trap levels and intraband transition of hot electrons injected into the Si bulk.

Novel integration of a microchannel with a silicon light emitting diode antifuse

Light emitting diode antifuses have been integrated into a microfluidic device that is realized with extended standard IC-compatible technological steps. The device comprises a microchannel sandwiched between a photodiode detector and a nanometre-scale diode antifuse light emitter. In this paper, the device fabrication process, working principle and properties and possible applications will be discussed. Changes in the interference fringe of the antifuse spectra due to the filling of the channel have been measured. Potential applications are electro-osmotic flow speed measurement, detection of absorptivity of liquids in the channel, detection of changes of the refractive index of the medium in the channel, e.g. air bubbles, particles in the liquid.

Photochemical Reaction by Nanometer-scale Light Emitting Diode-Antifuses

Silicon diode-antifuses with sizes in the nanometer range and emitting light in the visible and near ultraviolet, are employed as actuators for a photochemical process, i.e. the structure transformation of photoresist. Collective experiments were done to collect data for a correlation among exposure current, time and the size of the reaction products. A CMOS compatible integrated device with light detection capability has been realized and examined.