Radiation emitting semiconductor device

• US 20050003565A1
• Filed: 05/03/2004
• Published: 01/06/2005
• Est. Priority Date: 02/15/2000
• Status: Active Grant

• Current Assignee: OSRAM GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Mundbrod-Vangerow, Manfred, Kuehn, Frank, Strauss, Uwe, Eisert, Dominik, Zehnder, Ulrich, Haerle, Volker
• Granted Patent: US 7,195,942 B2
• Time in Patent Office: Days
• US Class Current: 438/22
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/32257 the layer connector connecting to a bonding area disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/10155 being other than a cuboid
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

Radiation-emitting semiconductor device, method for fabricating same and radiation-emitting optical device. A radiation-emitting semiconductor device with a multilayer structure (100) comprising a radiation-emitting active layer (10), with electrical contacts (30, 40) for impressing a current in the multilayer structure (100) and with a radiotransparent window layer (20). The window layer is arranged exclusively on the side of the multilayer structure (100) facing away from a main direction of radiation of the semiconductor device and has at least one side wall that includes a first side wall portion (20a) which extends obliquely, concavely or in a stepwise manner toward a central axis of the semiconductor device lying perpendicular to the multilayer sequence. In its subsequent extension toward the back side, viewed from the multilayer structure, the side wall changes over into a second side wall portion (20b) that extends perpendicularly to the multilayer structure, that is, parallel to the central axis, and the portion of the window layer (20) encompassing the second side wall portion (20b) forms a mounting pedestal for the semiconductor device. The first and second side wall portions are fabricated especially preferably by means of a saw blade having a shaped edge. In a preferred optical device, the semiconductor device is mounted window layer downward in a reflector cup.

Claims

1-11. -11. (Canceled).

12. A method for fabricating a plurality of radiation-emitting semiconductor devices, each said device including a multilayer structure that contains a radiation-emitting active layer and a radiotransparent window layer that is disposed on a side of said multilayer structure facing away from a main direction of radiation of the semiconductor device, said window layer including a first side wall portion which extends obliquely, concavely or in a stepwise manner with respect to a central axis of the semiconductor device lying perpendicular to the multilayer sequence, and which in its subsequent extension toward the back side, viewed from said multilayer structure, changes over into a second side wall portion that forms a mounting pedestal for said semiconductor device, said method comprising the following steps:

fabricating a plurality of mutually adjacent multilayer structures on a large area substrate wafer including a radiotransparent window layer,

sawing into said substrate wafer from the back of the substrate, with a saw blade having a shaped edge that has the negative shape of the intended oblique, concave or stepwise shape of said first side wall portions, to a predetermined depth at which the blade-shaped portion of said saw blade saws into said substrate, said saw blade also having a blade side surface having a negative shape of said second sidewall portion,

dividing said wafer along said sawcuts into separated devices, and

processing the separated devices further.

13. The method as recited in claim 12, wherein the dividing is done by means of a breaking method or a second sawcut.

14. The method as recited in claim 12 or 13, wherein before the back of said substrate is sawn into, metal contacts are produced on the unoccupied surfaces of said substrate or said multilayer structure.

15. The method of claim 12, wherein the sawing is performed with a saw blade having a V-shaped edge.

16. The method of claim 15 wherein a surface of said V-shaped edge forms with said central axis an angle that is between 20°

and 30°

.

17. The method of claim 12 wherein said second sidewall portion and said blade side surface extends parallel to said central axis.

18. The method of claim 12 wherein said substrate wafer is an epitaxial substrate, and said fabricating includes growing said multilayer structure on said epitaxial substrate.

19. The method of claim 12 wherein said further processing includes mounting a said separated device with a reflector cup that has a floor and oblique or paraboloid side walls such that said window layer is oriented toward the floor of said reflector cup.