Electromagnetic radiation emitting semiconductor chip and procedure for its production

• US 7,442,966 B2
• Filed: 10/24/2006
• Issued: 10/28/2008
• Est. Priority Date: 09/30/2002
• Status: Expired due to Term

• Current Assignee: OSRAM GmbH (Ams-Osram AG)
• Original Assignee: OSRAM GmbH (Ams-Osram AG)
• Inventors: Hahn, Berthold, Kaiser, Stephan, Eisert, Dominik, Bader, Stefan
• Primary Examiner(s): TRAN, MINH LOAN
• Application Number:
  US11/585,632
• Publication Number:
  US 20070034888A1
• Time in Patent Office: 735 Days
• Field of Search: 257/98, 257/103, 257/E33.068, 257/E33.072, 257/E33.074, 372/49.01, 372/50.11
• US Class Current: 257/98
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

A semiconductor chip which emits electromagnetic radiation is presented. The chip includes an epitaxially produced semiconductor layer stack based on nitride semiconductor material, which includes an n-conducting semiconductor layer, a p-conducting semiconductor layer, and an electromagnetic radiation generating region, which is arranged between these two semiconductor layers. The chip further includes a base on which the semiconductor layer stack is arranged, and a mirror layer, which is arranged between the semiconductor layer stack and the base. The n-conducting semiconductor layer faces away from the base, and the n-conducting semiconductor layer or an outcoupling layer located on the n-conducting semiconductor layer has a radiation-outcoupling surface which, in turn, includes planar outcoupling sub-surfaces, which are positioned obliquely with respect to a main plane of the radiation-generating region and each form an angle of between 15° and 70° with this plane.

Claims

1. A semiconductor chip which emits electromagnetic radiation, comprising:

an epitaxially produced semiconductor layer stack based on nitride semiconductor material, which includes an n-conducting semiconductor layer, a p-conducting semiconductor layer and an electromagnetic radiation generating region which is arranged between these two semiconductor layers;

a base, on which the semiconductor layer stack is arranged; and

a mirror layer comprising a highly reflective layer, a protective layer and a joining layer, said mirror layer being arranged between the semiconductor layer stack and the base;

wherein the n-conducting semiconductor layer faces away from the base; and

wherein the n-conducting semiconductor layer or an outcoupling layer located on the n-conducting semiconductor layer has a radiation-outcoupling surface which in turn includes a plurality of planar outcoupling sub-surfaces which are positioned obliquely with respect to a main plane of the radiation-generating region and each form an angle of between 15° and

70°

with this plane.

2. The semiconductor chip which emits electromagnetic radiation according to claim 1, wherein the outcoupling sub-surfaces form pyramid-like structures.

3. The semiconductor chip which emits electromagnetic radiation according to claim 1, wherein the semiconductor layer stack includes at least one trench which defines a plurality of individual semiconductor layer elements.

4. The semiconductor chip which emits electromagnetic radiation according to claim 3, wherein the semiconductor layer elements each have a diameter or a width which includes at most ten pyramid-like structures.

5. The semiconductor chip which emits electromagnetic radiation according to claim 3, wherein the trench(es) are at least sufficiently deep for them to isolate at least the radiation-generating region.

6. The semiconductor chip which emits electromagnetic radiation according to claim 3, wherein the width of the trench or trenches is at least double the depth of the trenches.

7. The semiconductor chip which emits electromagnetic radiation according claim 1, wherein the semiconductor chip is a thin-film component, from which a growth substrate wafer is at least partially removed after the epitaxially produced semiconductor layer stack has been grown.

8. The semiconductor chip which emits electromagnetic radiation according to claim 1, wherein the highly reflective layer includes silver or aluminum.

9. The semiconductor chip which emits electromagnetic radiation according to claim 1, wherein the protective layer contains titanium nitride.

10. The semiconductor chip which emits electromagnetic radiation according to claim 1, wherein the joining layer comprises gold, tin or an alloy comprised of gold and tin.