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US 2006/0186424 A1Published application
White LED and manufacturing method therefor
AssigneeKabushiki Kaisha Toshiba
InventorsAkira Fujimoto, Koji Asakawa
Life of this patent
Estimating the term…
Abstract
A white LED includes an LED chip formed on one main surface of a sapphire substrate, the LED chip being formed in a semiconductor stack structure including a light emitting layer and emitting light of a predetermined wavelength, a light extracting film applied on the other main surface of the substrate, the light extracting film being formed of a material having a refractive index within a range of ±5% of a refractive index of the substrate and a surface of the light extracting film that is located on an opposite side to the substrate being processed into a recess and projection shape, and a phosphor member provided on an opposite side of the substrate with respect to the light extracting film, and generating white light as light is incident thereon.
Claims21
A white light emitting diode (LED) comprising:
- a sapphire substrate having a first main surface and a second main surface located on an opposite side to the first main surface;
- a light emitting diode (LED) chip formed on the first main surface of the substrate, the LED chip being fabricated in a semiconductor stack structure including a light emitting layer and emitting light of a predetermined wavelength;
- a light extracting film formed on the second main surface of the substrate, the light extracting film being formed of a material having a refractive index within a range of ±5% of a refractive index of the substrate, and having a surface located on an opposite side to the substrate and processed into a recess and projection shape;
- and
- a phosphor member provided on the light extracting film on an opposite side thereof to the substrate, the phosphor member generating white light due to light incident thereon through the light extracting film.
2 more elements
A white light emitting diode (LED) comprising:
- a sapphire substrate having a first main surface and a second main surface located on an opposite side to the first main surface;
- a light emitting diode (LED) chip formed on the first main surface of the substrate, the LED chip being fabricated in a semiconductor stack structure including a light emitting layer and emitting light of a predetermined wavelength;
- a light extracting film formed on the second main surface of the substrate, the light extracting film being formed of a material having a refractive index within a range of ±5% of a refractive index of the substrate, and having a surface located on an opposite side to the substrate and including a plurality of projections, each of the plurality of projections including a conical mesa portion having a gradient refractive index structure, a cylindrical portion having a grating structure and a conical portion having a gradient refractive index structure in this order from the substrate side;
- and
- a phosphor member provided on the light extracting film on an opposite side thereof to the substrate, the phosphor member generating white light due to light incident thereon through the light extracting film.
2 more elements
A method of manufacturing a white light emitting device (LED), comprising:
- forming a light emitting diode (LED) chip of a semiconductor stack structure including a light emitting layer, on a first main surface of a sapphire substrate;
- forming a thin film having a refractive index within a range of ±5% of a refractive index of the substrate, on a second main surface of the substrate, which is located on an opposite side to the first main surface;
- forming a mask in which circular patterns are periodically arranged, on the thin film;
- forming a light extracting film having a recess and projection shape by selectively etching the thin film with a reactive ion etching method using the mask;
- and
- forming a phosphor film that generates white light due to light incident thereon, on the light extracting film.
3 more elements
A method of manufacturing a white light emitting diode (LED), comprising:
- forming a light emitting diode (LED) chip of a semiconductor stack structure including a light emitting layer, on a first main surface of a sapphire substrate;
- forming a thin film having a refractive index within a range of ±5% of a refractive index of the substrate, on a second main surface of the substrate, which is located on an opposite side to the first main surface;
- forming a mask in which circular patterns are periodically arranged, on the thin film;
- forming a plurality of cylindrical portions of projection structures by selectively etching the thin film with a reactive ion etching method using the mask;
- forming a mesa portion in a bottom portion of each of the plurality of cylindrical portions and a conical portion at a top of each of the plurality of cylindrical portions by etching the thin film by a physical etching method using an inert gas after removing the mask;
- and
- forming a phosphor film that generates white light due to light incident thereon, on the thin film in which the cylindrical portions, the mesa portions and the conical portions are formed.
4 more elements
A method of manufacturing a white light emitting diode (LED), comprising:
- forming a light emitting diode (LED) chip of a semiconductor stack structure including a light emitting layer, on a first main surface of a sapphire substrate;
- forming a plurality of columnar patterns on a second main surface of the substrate, which is located on an opposite side to the first main surface;
- burying gaps between the plurality of columnar patterns with a thin film having a refractive index within a range of ±5% of a refractive index of the substrate;
- forming a light extracting film made of the thin film and having a recess and projection shape by annealing the thin film after removing the plurality of columnar patterns;
- and
- forming a phosphor film that generates white light as light is incident thereon, on the light extracting film.
3 more elements
Dependencies are inferred from the claim text.