KR20110071927A - Method of fabrication of optical module and the same - Google Patents

Abstract

PURPOSE: A method for manufacturing an optical module and the optical module are provided to improve process efficiency by omitting a wire bonding for electrically connecting a device. CONSTITUTION: A plurality of optical devices are arranged on a substrate and respectively includes top electrodes and bottom electrodes. A passivation layer is coated on the substrate and the optical devices. A top electrode pad unit(310) electrically connects the top electrodes of an optical device exposed from the passivation layer in two adjacent optical devices. A connection unit(220) serially connects the top electrode pad unit. The first electrode unit includes an extension unit which is extended to one side of the substrate.

Description

Method of fabrication and optical module {Method of fabrication of Optical Module and the same}

The present invention relates to an optical module including a plurality of arranged optical elements and a method of manufacturing the same, and provides a method of manufacturing an optical module in which a wire bonding process is omitted and an optical module not including the bonded wire.

Generally, a light emitting diode (or a light emitting device) is a photoelectric conversion semiconductor device having a structure in which an N-type semiconductor and a P-type semiconductor are bonded to each other, and are configured to emit light by recombination of electrons and holes. A large number of such light emitting diodes are known, and GaN-based light emitting diodes are spotlighted as blue series. GaN-based light emitting diodes are manufactured by sequentially stacking GaN-based N-type semiconductor layers, active layers (or light-emitting layers), and P-type semiconductor layers on a substrate made of a material such as sapphire or SiC, for example.

1A, 1B, and 1C illustrate a light emitting system including a plurality of light emitting diodes in the related art.

FIG. 1A includes a plurality of arranged light emitting devices including an N-type semiconductor 20 and a P-type semiconductor 30 on an insulated substrate 10 such as sapphire. After stacking, the electrode pads 21 and 31 and the wire bonding 40 disposed on a part of the surface of the semiconductor material are formed as a means for forming a mesa structure by etching until a part of the N-type semiconductor is exposed and electrically connecting them. It includes.

FIG. 1B includes a plurality of arranged light emitting devices each including an N-type semiconductor layer 20 and a P-type semiconductor layer 30 on a substrate 11 in a conductor state such as SiC, and the NP on the substrate 11. In order to sequentially stack the type semiconductor materials 20 and 30 and then electrically connect them, an electrode pad 31 connecting the P type semiconductors and a wire bonding 40 connecting the type semiconductor materials 20 and 30 are included.

FIG. 1C shows an electrode pad 31 for connecting the N-type semiconductor 20 by removing the substrate under the N-type semiconductor 20 and inverting the PN to bond the carrier substrate 12 in the system of FIG. 1B. Wire bonding 40 connecting them is included.

Soldering is mainly used for bonding wires, which is a very cumbersome and expensive process. Specifically, 1) it is possible to process only one device at a time and it is impossible to perform a wire bonding process on a large number of chips at one time. 2) The wire bonding process is a very difficult process. In addition, in terms of reliability, there is a case that the bonded wire in the post-process, such as packaging, fall off and damage the device.

Therefore, in order to electrically connect a plurality of light emitting devices, a method of replacing electrical connection by wire bonding has been studied.

In addition, in the case of the optical module including not only the above-described light emitting diode but also various light receiving elements, laser diodes, and the like, wire bonding is increasingly required for a process that can be replaced with a complicated and expensive process.

An object of the present invention is to provide a manufacturing method of which the efficiency of the process is improved by omitting the wire bonding process for the electrical connection of the device in the manufacture of an optical module including a plurality of optical devices.

In addition, an object of the present invention is to provide a light emitting system having improved reliability of a product by being made of an optical element and an electrode material coated thereon without a wire bonded to each element by the above method.

As a means for solving the above problems, an aspect of the present invention is a plurality of photons arranged on a substrate, each having an upper electrode and a lower electrode, a passivation layer applied on the substrate and the photons, adjacent An optical device module comprising an upper electrode pad portion formed to electrically connect upper electrodes of an optical device exposed from a passivation layer in two photons.

Here, the term "optical device" means various types of "optoelectronic devices" that are not particularly limited, such as light emitting diodes, various light receiving devices, and laser diodes.

Preferably, a first electrode part is further formed including a connection part connecting the electrode pad parts in a row and an extension part connected to one side of the substrate.

Meanwhile, the substrate may be in an electrically insulated state. In this case, a lower electrode pad part connecting the exposed lower electrodes of the optical devices to each other, a connecting part connecting the lower electrode pad parts in a line, and the connecting part may be connected to the other side of the substrate. It may be configured to further include a second electrode portion consisting of an extension portion extending to the perpendicular to the end thereof.

Meanwhile, when the substrate is in an electrically conductive state, the structure in which the substrate is electrically connected to the lower electrode or the substrate itself may be the lower electrode.

In addition, the substrate may be an electrically conductive carrier substrate, and the substrate may be electrically connected to the lower electrode through the conductive bonding material layer.

Preferably, the plurality of optical elements are arranged in a matrix form, and the first electrode portion and the second electrode portion may be drawn in opposite directions and alternately disposed between the plurality of optical element strings.

In addition, the side of the optical element is formed to be inclined obliquely can be configured to facilitate the formation of the electrode pad portion.

Another aspect of the invention is a method of fabricating a plurality of optical elements, each of which is arranged on a substrate, each having an upper electrode and a lower electrode, wherein a passivation layer is formed over the substrate and the photons, wherein two adjacent photons are formed. Exposing an upper electrode of the photonic device from a passivation layer at a portion thereof; And an upper electrode pad portion formed to electrically connect the upper electrodes of the exposed optical element.

According to the present invention, in the manufacturing process of the optical module including a plurality of optical elements, no wire bonding for electrically connecting each optical element is required, thereby increasing the efficiency of the optical module production process.

In addition, a plurality of devices fabricated on the wafer can be used directly in an integrated state without being individually separated, thereby increasing the degree of integration of the devices.

In addition, since there is no wire bonded to each device, the reliability of the device may be improved, and an optical module having a clean design may be provided.

Hereinafter, the present invention will be described in detail with reference to the drawings. On the other hand, although the drawings of the embodiment of the present invention has been described with reference to the light emitting diode, the scope of the present invention is not limited thereto and may be applied to various devices of the optical device.

(First embodiment)

2A is a plan view showing a light emitting system including a plurality of light emitting elements arranged on a substrate as a first embodiment of the present invention, FIG. 2B is a sectional view taken along line II ', and FIG. 2C is a first embodiment of the present invention. Is a process flow diagram of the light emitting system. The structure according to the first embodiment may be called a planar type light emitting element.

Referring to FIGS. 2A and 2B, a plurality of light emitting devices 1 are arranged vertically and horizontally on the substrate 100, and electrode portions 2 and 3 are provided to electrically connect them. For example, the electrode parts 2 and 3 connect the upper electrode and the lower electrode of the light emitting element, for example, connecting the N-type semiconductor is called connecting the N-type electrode part and the P-type semiconductor to the P-type electrode part. It can also be defined. The N-type electrode portion 2 and the P-type electrode portion 3 may be interchanged with each other, the electrode portion may be used as an electrode by using the conductivity of the semiconductor material, or may further form another conductive material.

As shown in FIG. 2B, the N-type electrode part 2 connects the lower electrode pad part 210 disposed in a portion of the N-type semiconductor in one electrode part of the light emitting device, along the elements arranged in a row. The connecting portion 220 includes a connecting portion 220, and the connecting portion 220 extends to one side of the substrate 100, and includes an extending portion 230 which is formed perpendicularly to the end thereof. Except for the region where the lower electrode pad portion 210 is located, the remaining N-type semiconductor is coated with a passivation layer to maintain an insulating state.

Meanwhile, in the P-type electrode part 3, an upper electrode pad part 310 disposed on the P-type semiconductor surface may be formed over two adjacent upper surfaces, side surfaces, and a space therebetween, as shown in FIG. 2B. In addition, FIG. 2B illustrates a connection part 320 connecting the upper electrode pad part 310 in a line and an extension part 330 extending to one side of the substrate. In this case, as in the N-type semiconductor layer, except for a portion of the upper surface where the upper electrode pad part 310 is placed, the P-type semiconductor layer is coated with the passivation layer 400 and maintained in an insulating state.

On the other hand, according to Figure 2a, a plurality of optical elements are arranged in a matrix form, the N-type electrode portion 2 and the P-type electrode portion 3 has a form that is drawn in the opposite direction to each other between the plurality of optical element strings Alternately placed. According to this structure, the N-type electrode portion 2 and the P-type electrode portion 3 can be effectively implemented in a small area in the plurality of optical elements.

On the other hand, the light emitting system of the present embodiment can be more conspicuous when formed on an insulated substrate. That is, the light emitting device may be formed by sequentially stacking an N-type semiconductor material and a P-type semiconductor material on an insulating substrate and then etching the predetermined shape. At this time, a portion of the N-type semiconductor material on the insulating substrate is left to be etched without being entirely etched. Conventional photoresist, exposure and etching processes are used for etching the stacked semiconductor materials. For example, GaN series may be used as the semiconductor material.

Next, a method of manufacturing the light emitting system according to the first embodiment of the present invention will be described. 2C is a process flowchart of the light emitting system according to the first embodiment of the present invention.

Referring to FIG. 2C, semiconductor materials 110 and 120 may be epitaxially grown on the substrate 100 (FIG. 2C (a)). The substrate may be various kinds, which are not particularly limited, such as quartz, various compound semiconductor substrates, silicon substrates, etc., but it can be effectively applied to an insulating substrate. Epigrowth uses a known growth method. However, epitaxial growth forms a lamination structure suitable for light emitting devices. In this case, it is a matter of course that the semiconductor material may include some or all deposition methods other than epitaxial growth. This process may refer to a structure in which N-type and P-type semiconductors, etc., form both active regions and electrodes when the light emitting diodes are stacked.

Thereafter, the photoresist 130 is patterned to form regions for forming a plurality of light emitting elements (FIG. 2C (b)). Next, the photoresist 130 is reflowed to have a predetermined inclination angle (FIG. 2C (c)). The reason for the reflow is to have a predetermined angle of inclination of the side surfaces of the light emitting devices of the semiconductor materials 120 and 110 to be formed through etching later. This is because the electrode pad portion is formed over the side surfaces of the two light emitting devices in a post-stage process, and in order to improve coverage of the electrode material applied at this time, the side surface of the light emitting device is preferably etched obliquely and provided in an obliquely inclined form.

Meanwhile, the patterned area is a space for electrically separating the plurality of light emitting devices, and at least a portion of the semiconductor material is etched using the photoresist as a mask. At this time, the entire semiconductor layer P-type semiconductor material 120 layer is etched, and the N-type semiconductor material 110 is mesa patterned so that a portion is not etched (Fig. 2c (d)). The exposed area serves as an electrode in the future. On the other hand, when the substrate 100 is conductive, a structure in which all of the semiconductor material layers are etched and the substrate is used as the lower electrode is also possible.

Next, the photoresist 130 used as a mask is removed, and the passivation layer 140 is applied to the entire upper portion thereof. The passivation layer 140 may be formed of an insulating layer that performs an insulating function, and may also function as a protective film of a semiconductor material. Meanwhile, in the passivation layer 140, the region where the upper electrode or the lower electrode is to be formed is removed by using a photolithography process. That is, the photoresist 130 is applied over the passivation layer 140 and the passivation layer is etched in the region where the upper electrode or the lower electrode is to be formed (FIG. 2C (e)).

Next, the electrode material is deposited on the entire structure and finally the electrode material is patterned to complete the manufacture of the light emitting system. (C) The pattern of electrode material forms an upper electrode pad portion to electrically connect the upper electrodes of an optical element exposed from the passivation layer in two adjacent photons, and connects the exposed lower electrodes of the optical elements to each other. A lower electrode pad portion is formed.

In addition, when the upper and lower electrode pad portions are formed, a connecting portion connecting the upper electrode pad portions in a row and the connecting portion may include an electrode portion extending to one side of the substrate, a connecting portion connecting the lower electrode pad portion in a row, and the connecting portion to the other side of the substrate. The electrode portion may be formed together with an extension portion extending and perpendicularly formed at an end thereof.

(2nd Example)

3A is a plan view showing a light emitting system including a plurality of light emitting elements arranged on a substrate as a second embodiment of the present invention, FIG. 3B is a sectional view taken along line II ', and FIG. 3C is a second embodiment of the present invention. Is a process flow diagram of the light emitting system. The structure according to the second embodiment is also called a planar type light emitting element, which is a vertical light emitting system.

For convenience of explanation, the difference between the light emitting system according to the second embodiment and the first embodiment will be described. In this case, since the N-type electrode part may be formed through the entire substrate, only the P-type electrode part is provided.

According to FIG. 3A, a plurality of optical elements are arranged in a matrix form, and the P-type electrode part 3 has a shape that is drawn out in one direction. In more detail, the upper electrode pad part 310 is disposed between a plurality of optical device strings in a partial region of the semiconductor, and a connection part 320 for connecting them in a line along the devices arranged in a row is provided. 320 extends to one side of the substrate 100, and includes an extension 330 that reaches its end and is perpendicular to the end.

Referring to FIG. 3B, the P-type electrode unit 170 is additionally formed under the substrate 100.

3C is a diagram illustrating a method of manufacturing a light emitting system according to a second embodiment of the present invention.

For convenience of explanation, the difference from FIG. 2C will be mainly described. In the second embodiment, after performing photoresist reflow (FIG. 3C (c)), in the mesa etching process, all or some of the semiconductor materials are left without remaining in the mesa etching process. 3C (d). In the second embodiment, when the substrate is conductive, the lower electrode may be part of the substrate. Accordingly, the lower electrode may be separately formed on the back surface of the substrate 100 where no device is formed, or the entire substrate may be used as an electrode. In the mesa etching process, it is preferable to etch the semiconductor material to the substrate 100. In addition, a separate N-type electrode portion is not required.

Finally, the P-type electrode unit 150 is additionally formed separately under the substrate 100.

(Third Embodiment)

4A is a cross-sectional view showing a light emitting system including a plurality of light emitting elements arranged on a substrate as a third embodiment of the present invention, and FIG. 4B is a process flowchart of the light emitting system according to the third embodiment of the present invention. The top view of the light emitting system according to the third embodiment of the present invention is the same as that of Fig. 3A, and thus the illustration is omitted. The structure according to the third embodiment is a light emitting system manufactured by introducing a carrier substrate.

For convenience of explanation, the difference between the light emitting system according to the third embodiment and the second embodiment will be mainly described. In this case, since the P-type electrode part may be formed through the entire substrate, only the N-type electrode part is provided.

A plurality of optical elements are arranged in a matrix form, the N-type electrode portion has a form that is drawn out in one direction. An upper electrode pad portion disposed between a plurality of optical device rows in a portion of the semiconductor, and a connecting portion connecting the plurality of optical device rows in a line along the elements arranged in a row, wherein the connecting portion extends to one side of the substrate, It includes an extension formed vertically. See FIG. 3A for a plan view.

Referring to FIG. 4A, the N-type electrode part 370 is separately formed under the substrate 100, and a conductive bonding layer 105 is formed between the carrier substrate 100 and the semiconductor materials 110 and 120. It is.

4B illustrates a method of manufacturing a light emitting system according to a third embodiment of the present invention. For convenience of explanation, the difference from FIG. 3C will be mainly described. In the third embodiment, the N-type semiconductor material layer 120 and the P-type semiconductor material layer 110 are sequentially stacked on the growth substrate 90 and the carrier substrate ( The stacked semiconductor material is attached to the semiconductor layer 100 using the conductive layer bonding material layer 105 and the growth substrate 90 is removed.

The next process is the same as the process of FIG. 3C. Finally, the P-type electrode part 370 is additionally formed under the substrate 100.

Although the transparent conductive oxide is illustrated as being stacked on the light emitting device in this embodiment, the position and shape of the stack may vary depending on the shape and use of the light emitting device. In addition, it is also possible to apply a transparent conductive oxide on the upper surface of the optical device.

1A, 1B, 1C are side views of a conventional light emitting system.

2A to 2C are a plan view, a sectional view, and a process flowchart according to the first embodiment of the present invention.

3A to 3C are a plan view, a sectional view, and a process flowchart according to a second embodiment of the present invention.

4A and 4B are a cross sectional view and a process flowchart according to a third embodiment of the present invention.

Claims (13)

A plurality of photons arranged on a substrate, each having a top electrode and a bottom electrode, A passivation layer applied over said substrate and said photons; And an upper electrode pad portion configured to electrically connect the upper electrodes of the optical element exposed from the passivation layer in two adjacent photons. The method according to claim 1, And a first electrode part including a connection part connecting the upper electrode pad parts in a row and an extension part extending from the connection part to one side of the substrate. The method according to claim 1, The substrate is electrically insulated, A second electrode pad part connecting the exposed lower electrodes of the optical devices to each other, a connecting part connecting the lower electrode pad parts in a row, and a connecting part extending to the other side of the substrate and formed at an end thereof perpendicular to the second electrode pad part; An optical device module, characterized in that it further comprises an electrode. The method according to claim 1, The substrate is in an electrically conductive state, the optical device module electrically connected with the lower electrode. The method according to claim 1, The substrate is an electrically conductive carrier substrate, the substrate is electrically connected to the lower electrode through a conductive bonding material layer. The method of claim 3, The plurality of optical elements are arranged in a matrix form, And the first electrode part and the second electrode part are drawn in opposite directions and alternately disposed between the plurality of optical device columns. In claim 1, Optical device module, characterized in that the side of the optical device is inclined obliquely. A method of manufacturing a plurality of optical elements arranged on a substrate, each having a top electrode and a bottom electrode, Forming a passivation layer over the substrate and the photons, exposing the top electrode of the photo device from the passivation layer in two adjacent photons; And forming an upper electrode pad part electrically connected to the upper electrodes of the exposed optical device. The method of claim 8, When the upper electrode pad part is formed, a connecting part connecting the electrode pad parts in a line and a first electrode part extending together with the connecting part to one side of the substrate are manufactured. The method of claim 8, The substrate is electrically insulated, A lower electrode pad part connecting the exposed lower electrodes of the optical devices to each other, a connecting part connecting the lower electrode pad parts in a line, and an extension part extending to the other side of the substrate and perpendicularly formed at an end thereof; The method of manufacturing an optical device module, characterized in that it further comprises forming a two-electrode portion. The method of claim 8, The substrate is in an electrically conductive state, The substrate is a method of manufacturing an optical device module that functions as a lower electrode of the optical device. In claim 8, Side of the optical device is a method of manufacturing an optical device module, characterized in that etching in an obliquely inclined form. The method of claim 8, The substrate is a carrier substrate in an electrically conductive state, the substrate further comprises the step of electrically connecting the lower electrode through the conductive bonding material layer.

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