EP1284038A1 - Composant semi-conducteur luminescent - Google Patents

Composant semi-conducteur luminescent

Info

Publication number
EP1284038A1
EP1284038A1 EP01947152A EP01947152A EP1284038A1 EP 1284038 A1 EP1284038 A1 EP 1284038A1 EP 01947152 A EP01947152 A EP 01947152A EP 01947152 A EP01947152 A EP 01947152A EP 1284038 A1 EP1284038 A1 EP 1284038A1
Authority
EP
European Patent Office
Prior art keywords
layer
doped
semiconductor component
light
layers
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP01947152A
Other languages
German (de)
English (en)
Inventor
Wolfgang Faschinger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ams Osram International GmbH
Original Assignee
Osram Opto Semiconductors GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Osram Opto Semiconductors GmbH filed Critical Osram Opto Semiconductors GmbH
Publication of EP1284038A1 publication Critical patent/EP1284038A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/02—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor bodies
    • H01L33/26—Materials of the light emitting region
    • H01L33/28—Materials of the light emitting region containing only elements of Group II and Group VI of the Periodic Table
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/30—Structure or shape of the active region; Materials used for the active region
    • H01S5/32—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures
    • H01S5/327—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures in AIIBVI compounds, e.g. ZnCdSe-laser
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/30—Structure or shape of the active region; Materials used for the active region
    • H01S5/34—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
    • H01S5/347—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers in AIIBVI compounds, e.g. ZnCdSe- laser
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L33/005—Processes
    • H01L33/0083—Processes for devices with an active region comprising only II-VI compounds
    • H01L33/0087—Processes for devices with an active region comprising only II-VI compounds with a substrate not being a II-VI compound
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/02—Structural details or components not essential to laser action
    • H01S5/0206—Substrates, e.g. growth, shape, material, removal or bonding
    • H01S5/0218—Substrates comprising semiconducting materials from different groups of the periodic system than the active layer

Definitions

  • the invention relates to a light-emitting semiconductor component with a number of layers which predominantly consist of elements of groups II and VI of the periodic table.
  • the layers are applied epitaxially on a substrate, preferably made of InP, and have a p-doped cover layer and an n-doped cover layer, the lattice constants of which correspond to those of the substrate.
  • An undoped active layer lies between the two layers, which, in cooperation with its neighboring layers, forms a quantum well structure.
  • Semiconductor components with a quantum well structure are used in wide areas of technology. They are used as light emitting diodes, for example for signaling different operating states, or as laser diodes, e.g. B. in the optical recording or reproduction of images and sound on carrier material, laser printers, medical laser devices or material processing. Laser diodes of this type are characterized by a low threshold current, high output power and low beam divergence. These properties have led to light-emitting semiconductor components with a quantum well structure occupying a preferred position in application and development.
  • GaAs galium arsenide
  • GaAlAs galium aluminum arsenide
  • GaN galium nitride
  • ZnSeTe forms together with ZnCdSe a so-called type II system, which means that the electrons and holes are concentrated in different layers and therefore recombine spatially indirectly, i.e. inefficiently and strongly red-shifted.
  • This structure is generally not suitable for a laser, for example.
  • n-doped top layer n-ZnMgCdSe doped with Cl waveguide layer ZnMgCdSe active layer ZnCdSe undoped
  • the lattice constant of the active layer being equal to that of the neighboring layers and that of the substrate.
  • the object of the invention is to remedy these disadvantages and to meet the need for a light-emitting semiconductor component which provides light in the spectral range from green to blue and at the same time has a long service life.
  • a light-emitting semiconductor component which is composed of a number of layers, which consist predominantly of elements of groups II and VI of the periodic table, and have a p-doped cover layer and an n-doped cover layer, the respective lattice constant of which corresponds to that of the substrate , and contain an undoped active layer lying between the two layers, which forms a quantum well structure in cooperation with its neighboring layers, this object is achieved in that the lattice constant of the active layer is made smaller than that of the neighboring layers.
  • the performance increase achieved in semiconductor components according to the present invention is based on the knowledge that the drastic drop in performance in known semiconductor components from elements of groups II and VI of the periodic table has fundamental causes of a thermodynamic nature. To have recognized these connections is a credit present invention.
  • the causes are to be briefly explained on the basis of the above-mentioned layer structure of known semiconductor components.
  • the p — doping of ZnSe with nitrogen leads to an unstable nitrogen acceptor. It breaks down into a stable complex (N ⁇ -V se ) 3+ , consisting of an interstitial nitrogen atom Ni, and a selenium vacancy V se . This complex is positively charged and diffuses into the quantum well region of the active zone, particularly when the semiconductor component is in operation. There these complexes are captured, accumulated and, at higher concentrations, ultimately lead to the dark line defects.
  • the capture process is controlled by the mechanical stress between the active layer and the neighboring layers. Since the ZnCdSe of the active layer has a larger lattice constant than the ZnSe of the neighboring layer, the active layer has a compressive stress in relation to its two neighboring layers.
  • the compressive stress in the active zone of known laser diodes which are made up of elements from groups II and VI of the periodic table, favors the trapping of vacancies, since this process leads to a reduction in the lattice constants and thus to a decrease in the energy caused by stress. According to the laws of thermodynamics, this state, which is energetically smaller than that before the capture process, is the more stable state of both.
  • the trapping process can therefore be prevented if the active layer and neighboring layers are formed in such a way that a tensile stress prevails between them. In this case, the tension causes vacancies to be pushed back, thereby avoiding the formation of dark line defects.
  • the individual layers of the semiconductor component are applied to a substrate made of InP and have a p-doped cover layer, an n-doped cover layer and an undoped active layer in between.
  • MBE molecular beam epitaxy
  • the p- and n-doped cover layers have different chemical compositions.
  • the n-doped layer has Cd, the n-doped layer instead Te.
  • the Te in the p-doped layer not only has the role of setting the lattice constants of the active layer and neighboring layers to a defined difference and thus keeping vacancies away from the active layer, but also actively preventing the formation of vacancies.
  • Calculations and experiments have shown that in the case of semiconductor components whose p- and n-doped layers contain ZnSe, by introducing, for example, Te into the p-doped layer during the p-doping with nitrogen, the (N ⁇ -V SE ) 3+ - Complex is not stable and therefore does not form. Because of this instability, this complex therefore has no chance of diffusing into the active layer and generating dark line defects.
  • Te By introducing Te into the p-doped layer, the formation of the above-mentioned. stable complexes reduced proportionately, the formation of dark line defects during operation of the semiconductor device is further reduced.
  • the optimal effect is achieved by the greatest possible concentration of Te in the p-doped layer, i.e. H. when an element of the n-doped layer in the p-doped layer is completely replaced by Te.
  • Variants of this form of training are designed so that their p-doped layer contain the element Be and / or Cd.
  • the semiconductor component according to the invention can be designed as a spontaneously emitting light-emitting diode or an induced-emitting laser diode.
  • the structure described above from p-do- tied layer, active layer and n-doped layer is characteristic of a light emitting diode. If the semiconductor component is designed as a laser diode, additional layers are required, which can be found in the following overview.
  • the layer structure has two waveguide layers which enclose the active layer, the energy gap of which is smaller than that of the cover layer and two buffer layers between the substrate and p-doped layer.
  • the waveguide layers have the task of being perpendicular to the layer plane for the light generated in the active layer
  • the buffer layers have the task of intercepting electrical or crystallographic problems during the transition between the different materials.
  • the diode body thereby forms an optical resonator, in which laser light is generated when a current is applied, the strength of which exceeds the threshold current strength.
  • the structure and quantitative composition of the active layer have a significant influence on the properties of the emitted light.
  • the semiconductor component according to the invention can be designed in such a way that different forms of construction each produce light with properties that are different from one another.
  • the frequency or wavelength of the emitted light is of particular interest. It is determined by the energy gap between the valence and conduction band (or between their sub-levels) of the quantum well structure in the active layer.
  • the frequency can be specified within certain limits by the mixing ratio of the individual elements of the active layer to one another.
  • the lattice constant is determined by the mixing ratio and thereby the frequency of the emitted light is determined.
  • the quantitative composition of the individual layers from the elements mentioned is given by the following formulas. Layers with the elements are sufficient
  • ZnMgCdSe of the formula: Zn (1 _ x _y) Mg x Cd y Se with 0.4 ⁇ x ⁇ 0.6 and 0.15 ⁇ x ⁇ 0.3,
  • ZnMgSeTe of the formula: Zn ( ⁇ _ x - y) Mg x Se ( ⁇ . Y ) Te y with 0.4 ⁇ x ⁇ 0.6 and O, 15 ⁇ y ⁇ 0.3, ZnCdSe of the formula: Zn ⁇ ⁇ - x) Cd x Se with 0 ⁇ x ⁇ 0.5.
  • the Zn and Cd content of the active layer can be varied within wide limits and light of different wavelengths can be generated.
  • a variant of the present embodiment is designed such that the active layer has a high proportion of Cd and, accordingly, a low proportion of Zn.
  • the Light emitted by this variant is in the green spectral range.
  • a low proportion of Cd or a high proportion of Zn is specified in the active layer. This variant emits light in the blue spectral range.
  • An essential advantage of the semiconductor component according to the invention is that the wavelength of the emitted light can be set to any value between blue and green by specifying appropriate mixing ratios during manufacture.
  • the intensity of the radiation generated by the semiconductor component is determined by the current intensity of the current applied.
  • the intensity of the radiation increases with increasing current.
  • the intentiveness of the radiation emitted by the semiconductor component can also be varied by design specifications. These design specifications concern the number of quantum wells present in the active layer.
  • design specifications concern the number of quantum wells present in the active layer.
  • a structure with multiple quantum carriers is accordingly formed in the active layer. With this structure, the current of the externally applied current is the same
  • buffer layers are provided in addition to the layers forming the actual semiconductor component.
  • the task of these layers is to intercept electrical or crystallographic problems in the transition between the different materials.
  • a further development of this type has 2 further layers between the substrate and the n-doped cover layer, which layers are formed by n-GalnAs and n-ZnCdSe. Problems in the transition between the different materials can also be dealt with by the fact that the proportion of one or more elements within a layer changes continuously over the layer thickness.
  • Such a structure is used for the power supply of an advantageous variant of the semiconductor component according to the present invention.
  • the supply of the electrical current in the case of layered semiconductor components takes place i. d. R. across the layers.
  • Gold is mainly used as the contact material. If a gold layer is applied directly to a p-doped layer containing ZnSe, a contact with a relatively high resistance results. Contacts with lower resistance and also almost linear, i.e. H. ohmic current / voltage curve is obtained on layers containing ZnTe.
  • a further layer is therefore applied to the p-doped layer on the side facing away from the active layer, within which the proportion of Se continuously decreases, while that of Te continuously increases.
  • the contact for the power supply is attached to the layer surface with the high percentage of Te.
  • FIG. 1 energy level diagram of the semiconductor component according to the invention
  • FIG. 1 shows the course of this energy gap in the individual layers of the semiconductor component.
  • the individual layers of the semiconductor component are indicated in the drawing. They include one
  • p-doped cover layer 1 made of p-ZnMgTeSe with a thickness of 6 waveguide layer 2 made of ZnMgCdSe with a thickness of 7 active layer 3 made of ZnCdSe with a thickness of 8
  • Waveguide layer 4 made of ZnMgCdSe with a thickness of 9
  • n-doped cover layer 4 made of n-ZnMgCdSe with a thickness of 10
  • the valence band edge 11 and conduction band edge 12 are shown within the individual layers.
  • the energy gap between these two edges is represented by the distance 13 between the two curves. 14 indicates the energy gap within the active layer. The size of this gap is a measure of the frequency of the light radiation generated in the active layer.
  • An essential feature of the present invention is the asymmetrical expression of the course of the two band edges over the individual layers. This asymmetry is evident from the unequal step heights 15 and 16 or 15 'and 16'. The cause of this asymmetry is the asymmetrical, i.e. consisting of different elements, expansion of the p- and n-doped layer.
  • the semiconductor devices according to the present invention have a long service life. Measurement curves for this are shown in FIG. 2.
  • the first curve 20 shows the course of the intensity of the emitted radiation in a semiconductor component according to the prior art, which is based on GaAs and whose p-doped layer contains the elements ZnMgSSe, as a function of time.
  • the second curve 21 shows the corresponding profile for a semiconductor component according to the invention, built on InP with a p-doped layer made of ZnMgTeSe. Boundary conditions for this measurement are: room temperature, continuous wave operation (ie continuously emitting semiconductor element), current density 50A / cm 2 .
  • continuous wave operation ie continuously emitting semiconductor element
  • current density 50A / cm 2 One knows easily on both measurement curves that the service life of the semiconductor component according to the invention differs by orders of magnitude from that of the semiconductor component according to the prior art.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Optics & Photonics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • Chemical & Material Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Nanotechnology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Biophysics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Led Devices (AREA)
  • Semiconductor Lasers (AREA)

Abstract

L'invention concerne un composant semi-conducteur luminescent comprenant un certain nombre de couches qui sont constituées principalement d'éléments des groupes II et VI de la classification périodique des éléments, qui sont produites par épitaxie sur un substrat, de préférence InP, et qui présentent une couche de recouvrement dopée p et une couche de recouvrement dopée n dont les constantes de grille correspondent à celle du substrat. Les couches comprennent également une couche active non dopée située entre ces deux couches de recouvrement et formant, en coopération avec ses couches voisines, une structure de puits quantique, la constante de grille de la couche active étant inférieure à celle des couches voisines.
EP01947152A 2000-05-19 2001-05-21 Composant semi-conducteur luminescent Withdrawn EP1284038A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10024924A DE10024924A1 (de) 2000-05-19 2000-05-19 Licht emittierendes Halbleiterbauelement
DE10024924 2000-05-19
PCT/DE2001/001927 WO2001089046A1 (fr) 2000-05-19 2001-05-21 Composant semi-conducteur luminescent

Publications (1)

Publication Number Publication Date
EP1284038A1 true EP1284038A1 (fr) 2003-02-19

Family

ID=7642863

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01947152A Withdrawn EP1284038A1 (fr) 2000-05-19 2001-05-21 Composant semi-conducteur luminescent

Country Status (5)

Country Link
US (1) US7259404B2 (fr)
EP (1) EP1284038A1 (fr)
JP (1) JP2003533898A (fr)
DE (1) DE10024924A1 (fr)
WO (1) WO2001089046A1 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10242360B4 (de) * 2002-09-12 2007-09-27 Osram Opto Semiconductors Gmbh Optoelektronischer Halbleiterchip mit Übergitter
WO2005030904A1 (fr) 2003-09-24 2005-04-07 Osram Opto Semiconductors Gmbh Diode electroluminescente a emission verte
EP1664239B1 (fr) 2003-09-24 2013-01-30 OSRAM GmbH Diode electroluminescente a emission blanche presentant une temperature de couleur definie
GB0404922D0 (en) * 2004-03-04 2004-04-07 Dione Plc Secure card reader
JP5117114B2 (ja) * 2007-06-04 2013-01-09 ソニー株式会社 半導体素子
US20120050632A1 (en) * 2010-08-31 2012-03-01 Chi Lin Technology Co., Ltd. Display apparatus having quantum dot layer

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1994015369A1 (fr) * 1992-12-22 1994-07-07 Research Corporation Technologies, Inc. Dispositifs semi-conducteurs electroluminescents composes des groupes ii a vi et contact ohmique a cet effet
KR970005168B1 (ko) * 1993-01-26 1997-04-12 엘지전자 주식회사 청색 반도체 레이저 다이오드
US5422902A (en) * 1993-07-02 1995-06-06 Philips Electronics North America Corporation BeTe-ZnSe graded band gap ohmic contact to p-type ZnSe semiconductors
JP3586293B2 (ja) * 1994-07-11 2004-11-10 ソニー株式会社 半導体発光素子
JP3461611B2 (ja) * 1995-03-24 2003-10-27 正紀 村上 Ｉｉ−ｖｉ族化合物半導体装置及びその製造方法
JP2930032B2 (ja) * 1996-09-26 1999-08-03 日本電気株式会社 Ｉｉ−ｖｉ族化合物半導体発光素子およびその製造方法
US6031244A (en) * 1996-12-09 2000-02-29 Sony Corporation Luminescent semiconductor device with antidiffusion layer on active layer surface

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0189046A1 *

Also Published As

Publication number Publication date
JP2003533898A (ja) 2003-11-11
US7259404B2 (en) 2007-08-21
WO2001089046A1 (fr) 2001-11-22
US20040012010A1 (en) 2004-01-22
DE10024924A1 (de) 2001-11-29

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