Oki Data Corporation

Oki Electric Industry Co., Ltd.

Masaharu Nobori

Hiroyuki Fujiwara

Masumi Koizumi

Masumi Taninaka

Yukio Nakamura

Makoto Ishimaru

Aya Yamanaka

Mitsuhiko Ogihara

Hiroshi Hamano

Susumu Ozawa

Tsutomu Nomoto

Takao Kusano

According to the present invention, a light-emitting semiconductor device has light-emitting elements separated by isolation trenches, preferably on two sides of each light-emitting element. The device may be fabricated by forming a single band-shaped diffusion region, then forming trenches that divide the diffusion region into multiple regions, or by forming individual diffusion regions and then forming trenches between them. The trenches prevent overlap between adjacent light-emitting elements, regardless of their junction depth, enabling a high-density array to be fabricated while maintaining adequate junction depth.

Method of fabricating semiconductor light-emitting devices with isolation trenches

Semiconductor light-emitting device with isolation trenches, and method of fabricating same

A light-emitting-element array has a semiconductor layer formed on a current-blocking layer. Light-emitting elements are formed in the semiconductor layer by diffusion of an impurity of a different conductive type. An isolation trench divides the semiconductor layer into a first region and a remaining region, and divides the array of light-emitting elements into segments disposed alternately in these two regions, each segment preferably including one or two light-emitting elements. A first shared interconnecting pad is electrically coupled to the light-emitting elements in the first region by electrical paths not crossing the isolation trench. A second shared interconnecting pad is electrically coupled to light-emitting elements in the remaining semiconductor region by electrical paths crossing the isolation trench. The array can then be driven by a number of separate interconnecting pads equal to half the number of the light-emitting elements.

Light-emitting-element array

A semiconductor device has a substantially linear array of semiconductor blocks of one conductive type, each includes a diffusion region of the opposite conductive type and a electrode. The array is paralleled by an array of electrode pads, each connected to two semiconductor blocks, being connected to the diffusion region in one of the two semiconductor blocks and to the electrode in the other one of the two semiconductor blocks. The electrode pad can thus activate both semiconductor blocks, activating one semiconductor block when placed at one potential, and activating the other semiconductor block when placed at another potential. Efficient driving with a comparatively small number of electrode pads thus becomes possible.

Array of semiconductor elements with paired driving scheme

A light-emitting array can be driven by a matrix-type driving operation. When the packaging density of light-emitting elements is to be increased, the width of the element-separating region should be made narrower. The element-separating region extends over a considerable distance and therefore is apt to be adversely affected by particles. This tends to prevent formation of a good element-separating region, lowering manufacturing yield. An n-side electrode is arranged close to a predetermined number of LEDs. An element-separating region is formed to surround the LEDs and the n-side electrode, thereby defining a plurality of n-type semiconductor blocks. The element-separating region has a first portion that extends in a direction parallel to the line of the LEDs aligned and a second portion that extend between adjacent blocks. The first portion is wider than the second portion.

Light-emitting element array having an element separating region

An opto-electronic device has a diffusion area of one conductive type formed in a semiconductor substrate of another conductive type, an ohmic contact layer making contact with the diffusion area, and an electrode making contact with the ohmic contact layer. The diffusion area is formed by solid-phase diffusion. The same mask is used to define the patterns of both the diffusion source layer and the ohmic contact layer, so that the ohmic contact layer is self-aligned with the diffusion area.

Opto-electronic device with self-aligned ohmic contact layer

An alignment mark on a light-emitting diode (LED) array chip is formed together with the light-emitting areas of the diodes in the array, by use of a combined mask having a first part and a second part. An impurity is introduced through windows in the first part to form the light-emitting areas. Next the windows are covered with an etching resist, and the chip substrate is etched to create a topographic relief feature defined by the second part of the mask. This topographic relief feature is used as an alignment mark. When LED array chips having these alignment marks are mounted on a supporting surface, they are aligned by recognizing patterns of light reflected from the topographic relief, thereby detecting the positions of the alignment marks.

LED array alignment mark, method and mask for forming same, and LED

An end facet light emitting type LED has a slanted light emitting side wall relative to a substrate surface. A method for manufacturing end facet light emitting type light emitting devices prevents the pn-junction regions of the devices from being damaged while a semiconductor wafer is diced to separate light emitting devices from one another. A recess is formed on the semiconductor wafer having a depth which is deeper than the pn-junction. A portion to be cut during dicing of the wafer is vertically and horizontally separated from the pn-junction regions, so that if cracks occur when the wafer is diced, the cracks do not affect the light emitting characteristics of the devices.

End face light emitting type light emitting diode

An end face light-emitting-type LED has a first-conductive-type semiconductor substrate and a second-conductive-type diffusion region formed on a first surface of the first-conductive-type semiconductor substrate so as to have a depth within a predetermined value. The first-conductive-type semiconductor substrate has a second surface which meets the first surface at a predetermined angle with the first surface. A junction between the first-conductive-type semiconductor substrate and the second-conductive-type diffusion region includes an inclined portion with regard to the first surface in the vicinity of an edge portion of the junction which is on a side of the second surface, and light emerges from the junction via the second surface.

End face light-emitting-type LED, end face light-emitting-type LED array

In a fabricating method for an end face light emitting type LED array, p-type regions are formed by diffusing impurities into portions of a semiconductor substrate, using a diffusion prevention film as a mask. Subsequently, using the diffusion prevention film as a mask again, the semiconductor substrate is etched to form a concave portion therein so that light-emission end faces are formed on a side of the concave portion. With this arrangement, a positional misalignment between the p-type regions and the light-emission end faces is prevented.

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Hachioji, Japan

Masaharu Nobori