Semiconductor structure comprising active zones

• US 7,692,202 B2
• Filed: 01/26/2005
• Issued: 04/06/2010
• Est. Priority Date: 01/29/2004
• Status: Expired due to Fees

• Current Assignee: AZUR SPACE Solar Power GmbH (5N Plus, Inc.)
• Original Assignee: AZUR SPACE Solar Power GmbH (5N Plus, Inc.)
• Inventors: Bensch, Werner
• Primary Examiner(s): Hu; Shouxiang
• Application Number:
  US10/586,946
• Publication Number:
  US 20070158659A1
• Time in Patent Office: 1,896 Days
• Field of Search: 257/94, 257/96, 257/97, 257/E33.047, 257/E33.012, 257/E33.013, 257/E33.014
• US Class Current: 257/96
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 25/0756 Stacked arrangements of devices
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• 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 2924/3011 Impedance
• CPC Class Codes: H01L 31/109 the potential barrier being of the PN heterojunction type
• CPC Class Codes: H01L 31/11 characterised by two potential barriers, e.g. bipolar phototransistors
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence

Abstract

A semiconductor structure with active zones, such as light diodes or photodiodes, including a substrate (SUB) with at least two active zones (AZ1-AZn), each of which emits or absorbs a radiation of differing wavelength. According to the invention, a multi-wavelength diode may be achieved, in which a first (lower) active zone (AZ1) is grown on a surface of the substrate (SUB), with one or several further active zones (AZ1-Azn) epitaxially grown one on the other and the active zones (AZ1-AZn) are serially connected from the lower active zone (AZ1) to an upper active zone (AZn), by means of tunnel diodes (TD1-TDn), serving as low-impedance resistors.

Claims

1. A multi-wavelength light-emitting diode, comprising a substrate (SUB) with a plurality of active zones (AZ₁-AZ_n), each of said active zones emitting light of a different wavelength,

a first and lower active zone (AZ₁) of said active zones (AZ₁-AZ_n) being grown on a surface of the substrate (SUB),

at least one upper active zone (AZ_n), and

at least one further active zone (AZ₂-AZ_n-1) epitaxially grown between the lower active zone (AZ₁) and the upper active zone (AZ_n),

the lower active zone (AZ₁) having a low energetic band gap and each subsequent active zones (AZ₂-AZ_n) having a higher energetic band gap than a previous active zone,

the active zones being serially connected from the lower active zone (AZ₁) to the upper active zone (AZ_n) via at least one dividing layer (TD₁-TD_n) that serves as a low impedance resistor and as a substrate for growing a further or upper active zone, the at least one dividing layer being designed as a reciprocally polar np or pn junction in the form of an isolation diode or tunnel diode, and semiconductor materials used for growing or epitaxing the isolation diodes or tunnel diodes (TD) having either an indirect band junction or an energetic band gap, which in each case is higher than semiconductor materials that are used beneath it,

wherein an absorption layer (Abs_s) is grown directly on an upper surface of at least one active zone (AZ₁-AZ_n), the absorption layer being formed of a material which is the same as a pn layer of the active zone on which the absorption layer is grown, and which adjusts intensity of light emitted by the at least one active zone on which the absorption layer is grown to generate multiple photon-emission peaks of differing wavelengths with substantially equalized intensities within the multi-wavelength diode.

2. A light-emitting diode with active zones according to claim 1, wherein the material of the substrate (SUB) is selected from the group consisting of GaAs, Ge, InP, GaSb, GaP, InAs, Si, SiGe, SiC, SiGe:

C, sapphire, and diamond.

3. A light-emitting diode with active zones according to claim 1, wherein the active zones ((AZ₁-AZ_n) contain at least one material selected from the group consisting of GaAs, GaInP AlGaAs, GaInAs AlInGaP, GaAsN, GaN, GaInN, InN, GaInAlN, GaAlSb, GaInAlSb, CdTe, MgSe, MgS, 6HSiC, ZnTe, CgSe, GaAsSb, GaSb, InAsN, 4H—

—

SiC, a-Sn, BN, BP, BAs, AlN, ZnO, ZnS, ZnSe, CdSe, CdTe, HgS, HgSe, PbS, PbSe, PbTe, HgTe, HgCdTe, CdS, ZnSe, InSb, AlP, AlAs, AlSb, InAs, and AlSb.

4. A light-emitting diode with active zones according to claim 1, wherein:

the substrate (SUB) is GaAs or Ge,

the lower active zone is a GaAs lower diode (AZ₁) grown on the substrate,

grown on top of lower diode (AZ₁), in alternating sequence, is an isolation diode, followed by at least one said further active zone which is a GaInP diode (AZ₃) or Al-GaAs diode (AZ₃-AZ_n) grown on the isolation diode,

the band emission range being defined in that the number of diodes (AZ₁-AZ_n) and the number and the width of the peaks define a coincident light emission range which could not be achieved with a single peak, thus a resulting creation of an emission range.

5. A light-emitting diode with active zones according to claim 1, wherein each of the individual active zones (AZ₁-AZ_n) is equipped with a metallic contact for connection to a connecting lead.

6. A light-emitting diode with active zones according to claim 1, wherein the light-emitting diode is a blended-color LED (brown), and wherein:

the substrate (SUB) is GeAs or Ge,

the lower active zone (AZ₁) is made of GaInP or AlGaInP, grown on the substrate,

a first said dividing layer is grown on the lower active zone and is a first isolation diode (TD₁) made of GaInP or AlGaInP,

the at least one further active zone is a center active zone (AZ₂) made of AlInGaP, grown on the first isolation diode,

a second said dividing layer is a second isolation diode (TD₂) grown on the at least one center active zone, and

the upper active zone (AZ₃) is made of AlInGaP, grown on the second isolation diode.

7. A light-emitting diode with active zones according to claim 1, wherein the light-emitting diode is a blended-color LED, and wherein:

the substrate (SUB) is GeAs or Ge,

the lower active zone (AZ₁) is grown on the substrate, followed by two said further active zones, between which a tunnel diode is arranged, with the upper active zone (AZ_n) having a metallic contact for connection with an electrical terminal.

8. A light-emitting diode with active zones according to claim 1, wherein the lower active zone (AZ₁) is made of an AlInGaP material having a wavelength of approximately 620 nm, the at least one further active zone (AZ₂) is made of an AlInGaP semiconductor material having a wavelength of approximately 550 nm, and the upper active zone (AZ₃) is made of a GaInN semiconductor material having a wavelength of approximately 400 to 450 nm.

9. A light-emitting diode with active zones according to claim 1, wherein the upper active zone (AZ_n) has a contact which is a bond contact.

10. A light-emitting diode with active zones according to claim 1, wherein the light-emitting diode with the active zones forms a colored display.

11. A light-emitting diode with active zones according to claim 10, wherein the colored display is formed from a plurality of said light-emitting diodes, one pixel of the colored display corresponding to a light-emitting diode, and each pixel and the corresponding colors being selectively activated.