Group IV Semiconductor, Inc.

Mcmaster University

Thomas Macelwee

Iain D Calder

George Chik

Carla Miner

E Steven Hill

Howard Tweddle

Stephen Naor

Jean-Paul Noel

Alasdair Patrick Rankin

Steven E Hill

Dean Ducharme

Yongbao Xin

Peter Mascher

Marwan Albarghouti

Jacek Wojcik

Improved high quality gate dielectrics and methods of preparing such dielectrics are provided. Preferred dielectrics comprise a rare earth doped dielectric such as silicon dioxide or silicon oxynitride. In particular, cerium doped silicon dioxide shows an unexpectedly high charge-to-breakdown Q, believed to be due to conversion of excess hot electron energy as photons, which reduces deleterious hot electron effects such as creation of traps or other damage. Rare earth doped dielectrics therefore have particular application as gate dielectrics or gate insulators for semiconductor devices such as floating gate MOSFETs, as used in as flash memories, which rely on electron injection and charge transfer and storage.

High quality gate dielectric for semiconductor devices and method of formation thereof

A light emitting device structure, wherein the emitter layer structure comprises one or more device wells defined by thick field oxide regions, and a method of fabrication thereof are provided. Preferably, by defining device well regions after depositing the emitter layer structure, emitter layer structures with reduced topography may be provided, facilitating processing and improving layer to layer uniformity. The method is particularly applicable to multilayer emitter layer structures, e.g. comprising a layer stack of active layer/drift layer pairs. Preferably, active layers comprise a rare earth oxide, or rare earth doped dielectric such as silicon dioxide, silicon nitride, or silicon oxynitride, and respective drift layers comprise a suitable dielectric, preferably silicon dioxide, of an appropriate thickness to control excitation energy. Pixellated light emitting structures, or large area, high brightness emitter layer structures, e.g. for solid-state lighting applications, may therefore be provided with improved process flexibility and reliability.

Light emitting device structure and process for fabrication thereof

An engineered structure of a light emitting device comprises multiple layers of alternating active and buffer materials disposed between AC or DC electrodes, which generate an electric field. The active layers comprise luminescent centers, e.g. group IV semiconductor nanocrystals, in a host matrix, e.g. a wide bandgap semiconductor or dielectric material such as silicon dioxide or silicon nitride. The buffer layers are comprised of a wide bandgap semiconductor or dielectric material, and designed with a thickness, in the direction of an applied electric field, that ensures that electrons passing therethrough picks up enough energy to excite the luminescent centers in the adjacent active layer at an excitation energy to emit light efficiently at a desired wavelength.

Engineered structure for solid-state light emitters

Electroluminescent (EL) devices structures are provided comprising a hot electron stopper layer structure to capture hot electrons and dissipate their energy, thereby reducing damage to the transparent conducting oxide (TCO) layer and reducing other hot electron effects, such as charging effects, which impact reliability of EL device structures. The stopper layer structure may comprise a single layer or multiple layers provided between the TCO electrode layer and the emitter structure, and may also function to reduce diffusion or chemical interactions between the TCO and the emitter layer structure. Optionally, stopper layers may also be provided within the emitter structure. Suitable stopper layer materials are wideband gap semiconductors or dielectrics, preferably transparent at wavelengths emitted by the EL device characterized by high impact ionization rates, and/or high relative permittivity relative to adjacent layers of the emitter structure.

Light emitting device with a stopper layer structure

A light emitting device includes an active layer structure, which has one or more active layers with luminescent centers, e.g. a wide bandgap material with semiconductor nano-particles, deposited on a substrate. For the practical extraction of light from the active layer structure, a transparent electrode is disposed over the active layer structure and a base electrode is placed under the substrate. Transition layers, having a higher conductivity than a top layer of the active layer structure, are formed at contact regions between the upper transparent electrode and the active layer structure, and between the active layer structure and the substrate. Accordingly the high field regions associated with the active layer structure are moved back and away from contact regions, thereby reducing the electric field necessary to generate a desired current to flow between the transparent electrode, the active layer structure and the substrate, and reducing associated deleterious effects of larger electric fields.

Pixel structure for a solid state light emitting device

The present invention replaces conventional lighting devices, such as incandescent lamps, fluorescent lamps, and LED lamps, with an integrated electro-luminescent film structure, subdivided into electrically isolated micro-panels. Ideally, the electro-luminescent structure comprises separate red, green and blue micro-panels providing a full range of color adjustment. Alternatively, the electro-luminescent film structure includes stacked groups of layers, in which each group emits a different color and is independently controllable.

Color Tuneable electroluminescent devices

A solid state light emitting device comprises one or more active layers comprising semiconductor nano-particles in a host matrix, e.g. silicon nano-particles in silicon dioxide or silicon nitride. The incorporation of carbon in the active layers provides a great improvement in performance through shortened decay time and enhance emission spectra, as well as reliability and lifetime. The emission wavelengths from the nano-particles can be made to correspond to the quantization energy of the semiconductor nano-particles, which allows the entire visible range of the spectrum be covered. Ideally an engineered structure of alternating active and buffer material layers are disposed between AC or DC electrodes, which generate an electric field. The buffer layers are comprised of a wide bandgap semiconductor or dielectric material, and are designed with a thickness, in the direction of an applied electric field, that ensures that electrons passing therethrough picks up enough energy to excite the nano-particles in the adjacent active layer at a sufficient excitation energy to emit light efficiently at a desired wavelength.

Carbon passivation in solid-state light emitters

The present invention replaces the conventional cold cathode fluorescent tubes used in backlighting units of liquid crystal displays with an integrated electro-luminescent film structure, subdivided into electrically isolated micro-panels. Ideally, the electro-luminescent structure comprises separate red, green and blue micro-panels providing full color capabilities. Alternatively, the electro-luminescent film structure includes stacked groups of layers, in which each group emits a different color and is independently controllable.

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Nepean, Canada

Thomas Macelwee