KR101170193B1 - Light emitting devices having current blocking structures and methods of fabricating light emitting devices having current blocking structures - Google Patents

Abstract

Provided are methods of manufacturing light emitting devices and light emitting devices having a current blocking mechanism directly under the wire bond pads. The current blocking mechanism may be a reduced conductive region in the active region of the device. The current interruption mechanism may be a damage area over which a contact is formed. The current blocking mechanism can be a Schottky contact between the ohmic contact and the active region of the device. Semiconductor junctions, such as PN junctions, may also be provided between the ohmic contact and the active region.

Wire Bond Pads, Active Areas, Conductive Areas, Damage Areas, Schottky Contacts

Description

Light emitting devices having current blocking structures and methods of fabricating light emitting devices having current blocking structures

The present invention relates to semiconductor light emitting elements and their manufacturing methods.

Semiconductor light emitting devices such as light emitting diodes (LEDs) or laser diodes are widely used for many applications. As is well known to those skilled in the art, semiconductor light emitting devices include semiconductor light emitting elements having one or more semiconductor layers formed to emit coherent and / or non-coherent light when energized. As is well known to those skilled in the art, light emitting diodes or laser diodes generally comprise a diode region on a microelectronic substrate. The microelectronic substrate can be, for example, gallium arsenide, gallium phosphide, alloys thereof, silicon carbide and / or sapphire. Successive developments in LEDs have led to the emergence of highly efficient and mechanically robust light sources to cover the visible and invisible spectrum. These features, along with the potentially long operating life of solid state devices, can enable a variety of new display applications and allow LEDs to be in position to compete with well entrenched incandescent and fluorescent lamps.

Many development concerns and commercial activities have focused on LEDs fabricated on or on silicon carbide, as these LEDs can emit radiation of the blue / green portions of the visible spectrum. For example, reference may be made to U.S. Patent 5,416,342, which was invented by Edmond et al. And assigned to the applicant of the present application under the name "Blue Light-Emitting Diode With High External Quantum Efficiency," which is fully described herein. It is incorporated herein by reference as if in full. There has also been a great deal of interest in LEDs comprising gallium nitride based diode regions on silicon carbide substrates, since these devices can also emit high efficiency light. For example, reference may be made to U.S. Patent 6,177,688, invented by Linthicum et al. Under the name "Pendeoepitaxial Gallium Nitride Semiconductor Layers On Silicon Carbide Substrate," the disclosure of which is hereby incorporated by reference in its entirety herein. Is incorporated in.

The efficiency of conventional LEDs can be limited by the limitation of their ability to emit all the light generated by their active area. When the LED is energized, light emission in the active region (in all directions) may be prevented from leaving the LED, for example by a light absorbing wire bond pad. Typically, in gallium nitride based LEDs, a current spreading contact layer may be provided to improve the uniformity of carrier injection across the cross section of the light emitting device. Current is injected towards the p-side of the LED through the bond pads and p-type contacts. Light generated in the active region of the device is proportional to carrier injection. Thus, essentially uniform photon emission across the active region is due to the use of a current spreading layer, such as an intrinsically transparent p-type contact layer. However, wire bond pads are typically not transparent structures, so photons emitted in the active region of the LED, incident on the wire bond pads, can be absorbed by the wire bond pads. For example, in some cases about 70% of light incident on the wire bond pad can be absorbed. Absorption of such photons can reduce the amount of light exiting the LED and reduce the efficiency of the LED.

Certain embodiments of the present invention include an active region of semiconductor material; It provides a method for manufacturing light emitting devices and / or light emitting devices including; a first contact on the active region. The first contact has a bond pad region on the first contact. The reduced conductive region is located in the active region directly below the bond pad region of the first contact and blocks current flow through the active region in the region immediately below the bond pad region of the first contact. It is configured to. The second contact is electrically connected to the active region.

In other embodiments of the present invention, the reduced conductive region extends through the active region in the first contact. The reduced conductive region may extend from the first contact to the active region, toward or through the active region. A p-type semiconductor material may be disposed between the first contact and the active region. In such a case, the reduced conductive region may extend in the first contact, penetrating the p-type semiconductor material and penetrating the active region.

In further embodiments of the invention, the active region comprises a group III-nitride based active region. A bond pad may also be provided on the first contact in the bond pad region. The reduced conductive region may be self aligned with the bond pad. The reduced conductive region may be an insulating region. The reduced conductive region may be a region that does not absorb light. The reduced conductive region may comprise an implanted region.

In other embodiments of the invention, a group III-nitride based active region; Provided are methods for manufacturing light emitting devices and light emitting devices, including; a first contact directly on a group III-nitride based layer on the active region. The first contact has a first portion making an ohmic contact with the group III-nitride based layer and a second portion not making an ohmic contact with the group III-nitride based layer. The second portion corresponds to the bond pad region of the first contact. The second contact is electrically connected to the active region.

In further embodiments of the invention, the second portion corresponds to the area of damage at the interface between the group III-nitride based layer and the first contact. The damage region may be a wet or dry etched region of the group III-nitride based layer, the group III-nitride based layer exposed to a high energy plasma and / or a region of the first contact, group III exposed to H ₂ . A region of the nitride based layer and / or an area of the group III-nitride based layer exposed to a high energy laser.

In other embodiments of the present disclosure, a wire bond pad may be provided on the bond pad area of the first contact. Moreover, the first contact may comprise a platinum layer, and the platinum layer may be essentially transparent. In addition, the area of damage and the wire bond pads may be self aligned.

In other embodiments of the invention, an active region of a semiconductor material; A schottky contact on the active region; And a first ohmic contact on the active region and the schottky contact. A portion of the first ohmic contact on the schottky contact corresponds to a bond pad region of the first ohmic contact. The second ohmic contact is electrically connected to the active region. A bond pad may be provided on the bond pad area of the first ohmic contact. The active region may include a group III-nitride based active region.

In other embodiments of the invention, an active region of a semiconductor material; And a first ohmic contact on the active region. The first portion of the first ohmic contact is located directly on the region of the semiconductor material of the first conductivity type, and the second portion of the first ohmic contact is the opposite of the first conductivity type of the semiconductor material of the second conductivity type. Located directly on the area. The second portion corresponds to the bond pad region of the first ohmic contact. A second ohmic contact is electrically connected to the active region. The region of the second conductivity type semiconductor material may include a layer of the second conductivity type semiconductor material. The region of the semiconductor material of the first conductivity type may include a layer of the semiconductor material of the first conductivity type, and the region of the semiconductor material of the second conductivity type is disposed as a layer of the semiconductor material of the first conductivity type. Can be. The active region may include a group III-nitride based active region. A bond pad may also be provided on the bond pad area of the first ohmic contact.

1 is a cross-sectional view illustrating a semiconductor light emitting device having a current blocking structure according to some embodiments of the present invention.

2A and 2B are cross-sectional views illustrating the fabrication of semiconductor devices in accordance with certain embodiments of the present invention.

3 and 4 are cross-sectional views of light emitting devices according to other exemplary embodiments of the present invention.

The invention is now described in more detail below with reference to the accompanying drawings which illustrate embodiments of the invention. The invention should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Like reference numerals refer to like elements throughout the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the items described.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. When the terms "comprises" and / or "comprising" are used herein, they refer to the presence of the stated features, integers, steps, actions, elements and / or components, one or It is further understood that it does not exclude the presence or addition of other features, integers, steps, operations, elements, components, and / or collections thereof.

When one element, such as a layer, region or substrate, is said to be "on" or extend "onto" another element, the one element is directly on the other element ( It can be appreciated that there may be directly on, may extend directly onto another element, or there may be intervening elements. Conversely, when one element is said to be "directly" to another element or to "extend" another element, there are no intervening elements present. When one element is referred to as being "connected" or "coupled" to another element, it is to be understood that the one element may be directly connected to or directly coupled to another element or that intermediate elements may be present. have. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present. Throughout the invention, like reference numerals refer to like elements.

Although the terms first, second, etc. are used herein to describe various elements, components, regions, layers, and / or sections, such elements, components, It is to be understood that the regions, layers and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or portion from another region, layer or portion. Thus, the first element, component, region, layer or portion described below may be referred to as the second element, component, region, layer or portion without departing from the spirit of the invention.

Moreover, relative terms such as "bottom" or "bottom" and "top" or "normal" may be used herein to describe the relationship of one element to other elements as illustrated in the figures. It may be understood that relative terms are intended to include other directions of the device in addition to the direction depicted in the figures. For example, if an element in the figures is flipped over, elements described as being on the "bottom" side of the other elements may have an orientation on the "top" side of the other elements. Thus, the typical term "lower" may include both "lower" and "upper" directions depending on the particular direction of the figure. Similarly, if an element in one of the figures is flipped, elements described as "underneath" or "underneath other elements" may have a direction above "the other elements". . Thus, the typical terms "under or just below" may include two directions above and below.

Embodiments of the invention are described herein with reference to cross-sectional views that outline the idealized embodiments of the invention. As a result, variations from the forms of the figures, in turn, for example, variations in manufacturing techniques and / or tolerances, can be expected. Accordingly, embodiments of the present invention should not be construed as limited to the particular forms of regions illustrated herein, but should include variations in forms resulting from, for example, manufacturing. For example, an etched region illustrated or described as a rectangle may typically have circular or curved shapes. Accordingly, the areas illustrated in the figures are inherently schematic, and their shapes are not intended to illustrate the exact form of the area of the device and are not intended to limit the scope of the invention.

Unless defined otherwise, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms, such as those defined in commonly used dictionaries, should be interpreted to have meanings consistent with their meanings in the relevant technical field, and in an ideal or overly formal sense unless explicitly defined herein. It should not be interpreted.

It will be understood by those skilled in the art that the expression structure or form disposed “adjacent” to another form may have portions that cover or beneath the adjacent form.

Various embodiments of the LEDs disclosed herein include a substrate, but a crystalline epitaxial growth substrate, on which epitaxial layers comprising the LED grow thereon, may be removed, and better thermal, electrical, structural, and better than the original substrate. It will be understood by those skilled in the art that independent epitaxial layers may be mounted on an alternate carrier substrate or submount that may have optical properties. The invention described herein is not limited to structures having crystalline epitaxial growth substrates, and may be used in connection with structures in which epitaxial layers are removed from original growth substrates and bonded to alternative carrier substrates.

Certain embodiments of the present invention may provide improved efficacy of a light emitting device by reducing and / or preventing current flow in the active area of the device in the area immediately below the wire bond pad or other light absorbing structure. Accordingly, certain embodiments of the present invention can provide methods for manufacturing light emitting devices and light emitting devices having a current blocking mechanism under the wire bond pad. By reducing or preventing the current from being injected directly below the wire bond pad, the current may be more converted to photon emission in regions of the device that are not under the wire bond pad. Therefore, the possibility of light being absorbed by the wire bond pad may be lowered. In some embodiments of the present invention, an increase in the efficiency of the light emitting device according to some embodiments of the present invention may be proportional to the size of the wirebond pad.

Embodiments of the present invention may be particularly suitable for use in nitride based light emitting devices, such as group III-nitride based devices. As used herein, the term " Group III-nitride " refers to semiconducting formed between nitrogen and Group III elements in the periodic table such as aluminum (Al), gallium (Ga) and / or indium (In). Referencing compounds (semiconducting compounds). The term also refers to ternary and quaternary compounds such as AlGaN and AlInGaN. As will be well understood by those skilled in the art, group III elements can combine with nitrogen to form binary (eg GaN), ternary (eg AlGaN, AlInN) and quaternary (eg AlInGaN) compounds. . These compounds all have empirical formulas in which one mole of nitrogen is combined with one mole of the Group III elements. Therefore, formulas such as Al _x Ga _{1 - x} N (where 0 ≦ _x ≦ 1) are often used to describe these compounds. However, although embodiments of the present invention are described herein with reference to group III-nitride based light emitting devices such as gallium nitride based light emitting devices, certain embodiments of the present invention are described, for example, in GaAs and / or GaP based devices. It may be suitable for use in other semiconductor light emitting devices such as.

Light emitting devices in accordance with certain embodiments of the present invention may include light emitting diodes, laser diodes and / or other semiconductor devices, which may include silicon, silicon carbide, gallium nitride and / or other semiconductor materials. One or more semiconductor layers; A substrate, which may include sapphire, silicon, silicon carbide, and / or other microelectronic substrates; And one or more contact layers, which may include metal and / or other conductive layers. In some embodiments ultraviolet, blue and / or green LEDs may be provided. Methods of designing and manufacturing semiconductor light emitting devices are well known to those skilled in the art and need not be described in detail herein.

For example, light emitting devices in accordance with certain embodiments of the present invention are gallium nitride based LEDs and / or lasers fabricated on silicon carbide substrates such as devices manufactured and marketed by Cree of Durham, North Carolina. It may include structures such as structures. The present invention is described in US Pat. No. 6,201,262; 6,187,606; 6,120,600; 5,912,477; 5,739,554; 5,631,190; 5,604,135; 5,523,589; 5,416,342; 5,393,993; 5,338,944; 5,210,051; 5,027,168; 5,027,168; It may be suitable for using LED and / or laser structures that provide active regions, such as those described in 4,966,862 and / or 4,918,497, the contents of which are incorporated herein by reference as if fully set forth herein.

"Group III Nitride Based Light Emitting Diode Structures With a Quantum Well and Superlattice, Group III Nitride Based, as well as US Patent Publication No. US2002 / 0123164 A1 published under the name" Light Emitting Diodes Including Modifications for Light Extraction and Manufacturing Methods Therefor ". Other suitable LDE and / or laser structures are described in US Patent Publication No. US 2003/0006418 A1, published January 9, 2003, entitled “Quantum Well Structure and Group III Nitirde Based Superlattice Structures”. Moreover, a US application serial number filed on September 9, 2003, entitled “Phosphor-Coated Light Emitting Diodes Including Tapered Sidewalls and Fabrication Methods Therefor”, the contents of which are incorporated herein by reference in its entirety as if fully set forth. Phosphor-coated LEDs as described in 10 / 659,241 may also be suitable for use in embodiments of the present invention. LEDs and / or lasers may be configured such that light emission occurs through the substrate and is operated. In some embodiments, the substrate may be patterned to improve the light output of the devices, as described, for example, in the aforementioned US Patent Publication No. US 2002/0123164 A1. Such structures may be modified as described herein to provide blocking structures in accordance with certain embodiments of the present invention.

Thus, for example, embodiments of the present invention can be used in light emitting devices having bond pads of other shapes or sizes. The light emitting devices can be located on other substrates, such as silicon carbide, sapphire, gallium nitride, silicon or other group III nitride devices suitable for providing devices. The light emitting elements may be suitable for subsequent singulation and mounting on a suitable carrier. The light emitting devices may include, for example, single quantum wells, multiple quantum wells and / or bulk active area devices. Certain embodiments of the present invention can be used in devices using tunneling contacts on the p-side of the device.

1 is a schematic cross-sectional view of a light emitting device according to some embodiments of the present invention. Referring to FIG. 1, a substrate 10, such as an n-type silicon carbide substrate, has an optional n-type semiconductor layer 12, such as a gallium nitride based layer provided thereon. The n-type semiconductor layer 12 may include multiple layers, for example buffer layers and the like. In some embodiments of the present invention, n-type semiconductor layer 12 is provided with an AlGaN layer doped with silicon and a GaN layer doped with silicon, which may have a uniform composition or a gradient composition.

Although described herein with reference to a silicon carbide substrate, other substrate materials may be used in certain embodiments of the present invention. For example, sapphire substrates, GaN or other substrate materials may be used. In such a case, contact 20 may be located in a recess, for example, in contact with n-type semiconductor layer 12 to provide a second contact of the device. Other configurations can also be used.

Active regions 14, such as single or double heterostructures, quantum wells, multi-quantum wells or other such active regions, may be provided on the n-type semiconductor layer. As used herein, the term "active region" refers to a region of semiconductor material of a light emitting device, which may be one or more layers and / or portions thereof, in which photons emitted by the device during operation An essential part of these is generated by carrier recombination. In some embodiments of the invention, the active region refers to the region where essentially all photons emitted by the device are generated by carrier recombination.

An optional p-type semiconductor layer 16 is also illustrated in FIG. 1. The p-type semiconductor material layer 16 may be, for example, a gallium nitride based layer such as a GaN layer. In particular embodiments of the present invention, the p-type semiconductor layer 16 comprises magnesium doped GaN. The p-type semiconductor layer 16 may include one or multiple layers and may be of uniform composition or of gradient composition. In some embodiments of the present invention, the p-type semiconductor layer 16 is part of the active region 14.

A first contact metal layer 18 of contact metal may also be provided that provides an ohmic contact to the p-type semiconductor material layer 16. In some embodiments, first contact metal layer 18 may function as a current spreading layer. In particular embodiments of the present invention where the p-type semiconductor material layer 16 is GaN, the first contact metal layer 18 may be platinum (Pt). In some embodiments of the invention, the first contact metal layer 18 is light permeable, and in some embodiments is essentially transparent. In some embodiments, first contact metal layer 18 is a relatively thin platinum layer. For example, the first contact metal layer 18 may be a platinum layer having a thickness of about 54 kV. Wire bond pads 22 or other light absorbing regions are provided on first contact metal layer 18.

Also provided is a second contact metal layer 20 of contact metal that provides an ohmic contact to the n-type semiconductor material. The second contact metal layer 20 may be provided on one surface of the substrate 10 opposite to the active region 14. As mentioned above, in some embodiments of the present invention, the second contact metal layer is on a portion of the n-type semiconductor material layer 12, for example the bottom of a recess or mesa comprising the active region. On the face, it can be provided. Moreover, in some embodiments of the present invention, any backside implant or additional epitaxial layers may be provided between the substrate 10 and the second contact metal layer 20.

As further illustrated in FIG. 1, a reduced conduction region 30 is provided in the active region 14 and located just below the wire bond pad 22. In some embodiments of the present invention, the reduced conductive region 30 extends through the active region 14. As used herein, a reduced conductivity refers to a region having a reduced current flow relative to other portions of the active region. In particular embodiments, the reduction is at least one order in magnitude and in some embodiments essentially all current flow is blocked in the reduced conductive region. In some embodiments of the invention, the reduced conductive region 30 extends through the active region 14. In other embodiments of the present invention, the reduced conductive region 30 extends from the first contact metal layer 18 to the active region 14. In some embodiments, the reduced conductive region extends into the active region 14 in the first contact metal layer 18. In some embodiments, the reduced conductive region extends through the active region 14 in the first contact layer 18. The reduced conductive region 30 may have essentially the same shape and / or area as the region of the wire bond pad 22 on the first contact metal layer 18. In other embodiments of the present invention, the reduced conductive region 30 has a somewhat smaller area than the wire bond pad 22. In some embodiments of the present invention, the reduced conductive region 30 is a wire bond pad ( It has a somewhat larger area than 22). In some embodiments of the present invention, reduced conductive region 30 does not absorb light or only absorbs relatively small amounts of light. In some embodiments of the present invention, reduced conductive region 30 is an insulating region.

The reduced conductive region 30 may reduce and / or disrupt the flow of current through the active region 14 in the region immediately below the wire bond pad 22, thus preventing carrier recombination in this region. Can reduce and / or interfere with light generation. Although not constrained by a particular theory of operation, if photons are generated in a portion of the active region that is not directly under the wire bond pad 22, photons generated in a portion of the active region directly under the wire bond pad 22 This may be of course because the likelihood that is absorbed by the wire bond pad 22 may be higher. By reducing or eliminating light generated in the active region directly below the wire bond pad 22, a portion of the light generated by the light emitting element absorbed by the wire bond pad 22 can be reduced. Under certain operating conditions, this reduction in the amount of light absorbed by the wire bond pad 22 is compared with a device operated under the same conditions in which light is generated in an area located directly below the wire bond pad 22. Thus, increased light extraction from the light emitting device can be derived. Thus, certain embodiments of the present invention extend into and, in some embodiments, through the active region 14 in an area located directly below the wire bond pad 22. The conductive region 30 is provided. This may reduce the likelihood that carriers will diffuse and inject into the active area directly below the wire bond pad 22 and thus generate photons in the area located directly below the wire bond pad 22. have.

2A and 2B illustrate operations in accordance with certain embodiments of the present invention to form light emitting devices having a reduced conductive region illustrated in FIG. 1. As shown in Fig. 2A, various layers / regions of the light emitting device are fabricated. Specific operations in the manufacture of light emitting devices do not need to be repeated here, as they depend on the structure to be manufactured and are described in the US patents and / or applications, cited and incorporated above and / or well known to those skilled in the art. 2A also illustrates the formation of a mask 40 having openings 42 corresponding to the areas where the wire bond pads 22 are to be formed.

In order to form a reduced conductive region 30 as shown in FIG. 2B, implantation is performed using a mask 40 to implant atoms across the active region 14 in the region of the wire bond pad 22. do. Such injection may for example be a nitrogen injection. For example, for gallium nitride based devices, implantation conditions of 60 keV, 2 × 10 ¹³ cm ⁻³ nitrogen can produce non-absorbing and insulating regions of magnesium doped GaN. The particular implantation energy and / or atoms may depend on the structure in which the reduced conductive region 30 is formed.

As shown in FIG. 2B, after implantation, a wire bond pad 22 may be formed in the opening 42. Thus, in some embodiments of the present invention, wire bond pad 22 and reduced conductive region 30 may be self aligned. The wire bond pad 22 may be formed by, for example, forming a layer or layers of metal on which the wire bond pad 22 is formed and then planarizing the layers to provide the wire bond pad 22. Can be. Mask 40 may then be removed. Optionally, mask 40 may be composed of an insulating material, such as SiO 2 and / or AlN, and may remain or be removed on the device, for example, as a passivation layer.

3 illustrates light emitting devices according to other embodiments of the present invention. In FIG. 3, the first contact metal layer 18 is in contact with the p-type semiconductor material layer 16 which provides ohmic contact to the p-type semiconductor material layer 16 and the p-type semiconductor. A second portion 57 is in contact with the p-type semiconductor material layer 16 that does not form an ohmic contact in the material layer 16. As used herein, the term "omic contact" refers to a specific contact resistivity lower than about 10e ^-03 ohm-cm ² , and in some embodiments a contact resistivity lower than about 10e ^-04 ohm-cm ^2. Refers to. Thus, a contact that has a high contact resistivity of rectifying or greater than about 10 e- ⁰³ ohm-cm ² is not an ohmic contact as the term used herein.

The second portion 57 corresponds to the position of the wire bond pad 22. By not forming an ohmic contact, the current injection towards the p-type semiconductor material layer 16 at portion 57 may be reduced and / or interrupted. The portion 57 that does not form an ohmic contact may damage the p-type semiconductor layer 16 and / or the first contact metal layer 18 in a region located directly below the wire bond pad 22. By providing.

For example, in gallium nitride based devices, the interface level between the contact metal and the p-type semiconductor material may determine the quality of the ohmic contact that is derived. Thus, for example, the p-type semiconductor material layer 16 in the region 50 may have a high content such as argon (Ar) to reduce the p-type conductivity prior to forming the first contact metal layer 18. May be exposed to an energy plasma. In addition, the p-type semiconductor material layer 16 and the first contact metal layer 18 in the region 50 may be subjected to a high energy plasma to damage the metal / GaN interface after formation of the first contact metal layer 18. May be exposed. The p-type semiconductor material 16 in the region 50 may be exposed to hydrogen (H 2) while protecting other regions of the p-type semiconductor material layer 16 prior to forming the first contact metal layer 18. have. Prior to forming the first contact metal layer 18, the p-type semiconductor material 16 in the region 50 may be wet etched or dry etched while protecting other regions of the p-type semiconductor material layer 16. Can be. In addition, the p-type semiconductor material layer 16 of the region 50 may be exposed to a high energy laser while protecting other regions of the p-type semiconductor material 16 prior to the formation of the first contact metal layer 18. .

Applying such selective damage to the p-type semiconductor material layer 16 and / or the metal layer 18 may be performed using the mask described above with reference to FIGS. 2A and 2B and / or to adjust the laser, for example. By providing. The particular conditions used may vary depending on the procedure used and the composition of the P-type semiconductor material layer 16 and / or the first metal contact layer 18.

4 illustrates light emitting devices according to other embodiments of the present invention. In FIG. 4, a Schottky contact 60 is provided on the P-type semiconductor material layer 16, and the first contact metal layer 18 ′ is the p-type semiconductor material layer 16 and the Schottky contact 60. Is formed on the phase. Wire bond pads 22 are provided on the first contact metal layer 18 ′ on the Schottky contact 60. By forming the schottky contact 60, current injection from the first contact metal layer 18 ′ to the p-type semiconductor material layer 16 can be reduced and / or disturbed in the region of the schottky contact 60. .

Alternatively, a rectifying junction may be provided in the region located below the wire bond pad 22. Rectifying junctions may be provided, for example, by implanting n-type ions into the p-type semiconductor material layer 16 to convert the region immediately below the wire bond pad 22 into an n-type semiconductor material. have. Such implantation may be performed using a mask, for example as described above with reference to FIGS. 2A and 2B. Alternatively, an area of n-type material may be formed at the location where the Schottky contact is illustrated in FIG. 4, and the first contact metal is formed on the area of the n-type semiconductor material and p-type semiconductor material layer 16. 18 'may be formed.

Although embodiments of the present invention are illustrated with reference to particular light emitting device structures in Figures 1-4, other structures may be provided in accordance with some embodiments of the present invention. Thus, embodiments of the present invention may be provided by any light emitting structure including one or more of various current blocking mechanisms as described above. For example, current blocking mechanisms in accordance with certain embodiments of the present invention may be provided in combination with a typical light emitting device described in the US patents and / or applications incorporated herein by reference.

Embodiments of the present invention have been described with reference to wire bond pads 22. As used herein, the term bond pad refers to the light absorbing contact structure. The bond pads may be single or multiple layers, may be metal and / or metal alloys, and / or may be of uniform or non-uniform composition.

Moreover, although embodiments of the present invention have been described with reference to a particular order of operations, variations from the described order may be provided while still benefiting from the technical spirit of the present invention. Thus, two or more steps may be combined with a single step or steps performed in the order described herein. For example, the reduced conductive region 30 may be formed before or after forming the second contact metal layer 20. Accordingly, embodiments of the present invention should not be construed as limited to the particular order of operations described herein unless stated otherwise herein.

Various embodiments of the invention can be understood by those skilled in the art, individually described in connection with FIGS. 1-4. However, combinations and subcombinations of the embodiments of FIGS. 1-4 may be provided in accordance with various embodiments of the present invention.

In the drawings and specification, there have been disclosed embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being described in the following claims .

According to the method of manufacturing light emitting devices and light emitting devices according to the present invention, the amount of light emitted from the light emitting device can be increased and the efficiency of the light emitting device can be increased.

Claims (56)

delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete Forming an active region of a semiconductor material; Forming the first contact on the active region, having a bond pad region on the first contact; Disposed in the active region directly below the bond pad region of the first contact and configured to block flow of current through the active region in the region located directly below the bond pad region of the first contact Forming a reduced conductive region; And Forming a second contact electrically connected to the active region; 32. The method of claim 31, wherein the reduced conductive region extends from the first contact to the active region. 32. The method of claim 31, wherein the reduced conductive region extends from the first contact toward the active region. 32. The method of claim 31, wherein the reduced conductive region extends through the active region in the first contact. 32. The method of claim 31, wherein the reduced conductive region extends through the active region. 32. The method of claim 31, further comprising forming a p-type semiconductor material positioned between the first contact and the active region; And wherein the reduced conductive region extends in the first contact and penetrates the p-type semiconductor material and penetrates the active region. 32. The method of claim 31, wherein the active region comprises a group III-nitride based active region. 32. The method of claim 31, further comprising forming a bond pad on the first contact in the bond pad region. 39. The method of claim 38, wherein the reduced conductive region is self aligned with the bond pad. 32. The method of claim 31, wherein forming the reduced conductive region comprises: Forming a mask layer on the first ohmic contact, the mask layer having an opening corresponding to the bond pad region; and And injecting atoms into the active region through the openings of the mask layer. 41. The method of claim 40, further comprising forming a bond pad in the opening of the mask layer. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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