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Light-emitting device using a group III nitride compound semiconductor and a method of manufacture

a technology of nitride compound semiconductor and light-emitting device, which is applied in the direction of semiconductor/solid-state device manufacturing, semiconductor devices, electrical appliances, etc., can solve the problems of difficult mass production, sale, and use of such light-emitting devices using group iii nitride compound semiconductor, and achieves long service life, increased luminous output, and low cost.

Inactive Publication Date: 2005-06-23
TOYODA GOSEI CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention provides a structure for a light-emitting device that has an increased luminous output and a longer performance life at a low cost. The invention includes a mirror structure formed by laminating a light transmission layer and a reflective layer onto a substrate. The mirror structure can be made of metals or ceramic materials having sufficient luminous transparency. The invention also provides a method for manufacturing the light-emitting device using a group III nitride compound semiconductor that includes the steps of sequentially laminating a light transmission layer, a reflective layer, and a corrosion-resisting layer on the reverse side of a substrate. The invention solves the problem of low-cost mass production of light-emitting devices with improved luminous output and performance life.

Problems solved by technology

In the conventional manufacturing processes, however, leave two significant problems unsolved.
As a result, the mass production, sale, and use of such light-emitting devices using group III nitride compound semiconductor and including a reflective metal layer has not been easy.
The first problem relates to the formation of the split lines.
Because the blade of such a scribing cutter will tend to be clogged by any metal layer laminated on the reverse side of the substrate, the split lines cannot be formed after the metal layer is formed.
However, a metal layer formed on the surface to be cut would hinder the positioning.
Because these devices cannot be commercialized, a portion of the wafer is wasted and production efficiency is reduced.
Yet another problem associated with the conventional scribing process is that a semiconductor wafer being scribed is typically fixed to an adhesive sheet.
When the metal layer is being formed on the reverse side of the substrate, a portion of the sheet materials, in particular the adhesive, tends to volatilize and release abundant and undesirable gases during the deposition of the metal layer.
Another significant problem relates to the corrosion resistance of the resulting mirror structure.
When adhesives (such as paste materials including silver are used to bond the mirror structure of the light-emitting device to other structures such as leadframes, submounts, and stem contacts, the resulting alloying and oxidation effects can cause the metal layer to deteriorate and, as a result, lower the reflectivity of the mirror structure.
The reflective layer of the light-emitting device may also be damaged during and / or after the scribing and separation processes.

Method used

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  • Light-emitting device using a group III nitride compound semiconductor and a method of manufacture
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  • Light-emitting device using a group III nitride compound semiconductor and a method of manufacture

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first embodiment

[0080]FIG. 1 is a cross-sectional view showing the structure of a light-emitting device 100 using group III nitride compound semiconductor (hereinafter referred to as a light-emitting semiconductor device 100 or simply as a device 100). The light-emitting device 100 has almost the same structure as that of a conventional light-emitting semiconductor device 900 shown in FIG. 14, but the light-emitting device 100 further comprises a mirror structure 10 for reflecting light formed on the reverse side of a substrate 11.

[0081] The structure of the light-emitting semiconductor device 100 of the present invention is described more fully below.

[0082] The light-emitting semiconductor device 100 comprises a substrate 11, preferably formed into an approximately square shape. On the substrate 11, a buffer layer 12 consisting of aluminum nitride (AlN), which has a thickness of about 25 nm, and an n+-layer (an n-type contact layer) 13 having a high carrier concentration consisting of silicon (S...

second embodiment

[0127] In this embodiment, a method for manufacturing a light-emitting device 100 using a group III nitride compound semiconductor, which is shown in FIG. 1, from a semiconductor wafer 300 shown in FIG. 4 is explained.

[0128]FIG. 4 is a plan view of the semiconductor wafer 300 viewed from the substrate side (11b) after carrying out the polishing process. The semiconductor wafer 300 is the same as the semiconductor wafer 200 in the first embodiment.

[0129] The semiconductor wafer 300 was cleaned using an organic washing solvent such as acetone, IPA, etc. with the temperature of the surface of the substrate being raised to about 150° C.

[0130]FIGS. 10A-10C are views showing a process for forming a mask. FIGS. 10A and 10B are plan views and FIG. 10C is a cross-sectional view of the semiconductor wafer 300 showing processes of forming a mask and the mirror structure.

[0131] As shown in FIG. 10A, the light-emitting device 100 using a group III nitride compound semiconductor, which is to ...

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Abstract

A process of forming separation grooves for separating a semiconductor wafer into individual light-emitting devices, a process for thinning the substrate, process for adhering the wafer to the adhesive sheet to expose a substrate surface on the reverse or backside of the wafer, a scribing process for forming split lines in the substrate for dividing the wafer into light-emitting devices, and a process of forming a mirror structure comprising a light transmission layer, a reflective layer, and a corrosion-resistant layer, which are laminated in sequence using sputtering or deposition processes. Because the light transmission layer is laminated on the adhesive sheet, gases normally volatilized from the adhesion materials are sealed and do not chemically combine with the metal being deposited as the reflective layer. As a result, reflectivity of the reflective layer can be maintained.

Description

[0001] This is a patent application based on a Japanese patent application No. 2000-96495 which had been filed on Mar. 31, 2000. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a light-emitting device using a group III nitride compound semiconductor and a method for manufacturing such a device. In particular, the present invention relates to the structure of a mirror structure formed on the reverse side of a substrate and a method for forming the mirror structure. [0004] 2. Description of the Related Art [0005] A variety of light-emitting devices using group III nitride compound semiconductor comprising a mirror structure formed on the reverse side or backside of a substrate and a variety of methods for manufacturing such devices are generally known in the art. For example, Japanese patent Application Laid-Open (kokai) No. 11-126924 (Title: “Method of manufacturing gallium nitride compound semiconductor element”) (hereinafter refe...

Claims

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Application Information

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Patent Type & Authority Applications(United States)
IPC IPC(8): H01L33/00H01L33/10H01L33/32H01L33/46H01L33/60
CPCH01L33/0095H01L33/46H01L33/32
Inventor UEMURA, TOSHIYANAGASAKA, NAOHISAHASHIMURA, MASAKIHIRANO, ATSUOTADANO, HIROSHIKACHI, TETSUHOSOKAWA, HIDEKI
Owner TOYODA GOSEI CO LTD