TWI557407B - Method of chip inspection - Google Patents

Description

Grain detection method

The present invention relates to a method for detecting a crystal grain, and more particularly to a method for detecting a crystal grain, which provides a first light source that emits a first light source under the first die to be tested, wherein a portion of the first light passes through A side surface of a die to be measured is incident on the first die to be tested, and a portion of the first light is incident on the first die to be tested via a lower surface of the first die to be tested.

Light Emitting Diode (LED) is a solid-state semiconductor light-emitting device, which has the advantages of low power consumption, low heat energy, long working life, shock resistance, small volume, fast response speed and good photoelectric characteristics, for example. Stable light emission wavelength. Therefore, the light-emitting diodes are widely used in household appliances, equipment indicator lights, and optoelectronic products.

In the semiconductor manufacturing process of light-emitting diodes, defects are often formed for some unavoidable reasons. Therefore, in order to maintain the stability of product quality, in the semiconductor manufacturing process, defects must be made according to customer or user requirements for the products to be manufactured. Detecting, and then detecting the products that do not meet the customer or user requirements according to the test results, or analyzing the cause of the defects, and then avoiding the adjustment of the process parameters. Eliminate or reduce the occurrence of defects to achieve the goal of improving process yield and reliability.

The present invention provides a method for detecting a die, comprising: providing a first die to be tested, including a lower surface, a side surface, and an upper surface; and providing a first light source capable of emitting a first light to be located at the first Below the die, a portion of the first light enters the first die to be tested via the side surface, and a portion of the first light enters the first die to be tested via the lower surface.

The above described features and advantages of the invention will be apparent from the following description.

1‧‧‧ grain inspection device

2‧‧‧Grade carrier

3‧‧‧ grain

3a‧‧‧standard grain

3b‧‧‧First die to be tested

D‧‧‧ cutting road

S1‧‧‧ lower surface

S2‧‧‧ side surface

S3‧‧‧ upper surface

11‧‧‧Photosensitive element

12‧‧‧ fourth source

121‧‧‧fourth light

13‧‧‧second light source

131‧‧‧second light

14‧‧‧First light source

141‧‧‧First light

15‧‧‧ Third light source

151‧‧‧3rd light

30‧‧‧Semiconductor laminate

31‧‧‧First type semiconductor layer

32‧‧‧Second type semiconductor layer

33‧‧‧ active layer

34‧‧‧Reflective structure

35a‧‧‧Electrode structure

35b‧‧‧electrode structure

351‧‧‧ Defects

36‧‧‧Substrate

5‧‧‧Grade to be tested

50‧‧‧electrode pads

51‧‧‧Semiconductor laminate

6‧‧‧Grade to be tested

60‧‧‧electrode pads

61‧‧‧Semiconductor laminate

61a‧‧ images

7‧‧‧ standard grain

70‧‧‧electrode pads

71‧‧‧Semiconductor laminate

71a‧‧‧Image

61b‧‧‧ Defective imagery

7a‧‧‧First direction

7b‧‧‧second direction

1 is a schematic view of a die detecting apparatus disclosed in an embodiment of the present invention.

2A is a top view of an electrode structure of a standard crystal grain disclosed in an embodiment of the present invention.

2B is a partial schematic view of a die detecting apparatus according to an embodiment of the present invention.

3A is a top view of an electrode structure of a die to be tested disclosed in an embodiment of the present invention.

FIG. 3B is a partial diagram of a die detecting device according to an embodiment of the invention. intention.

FIG. 4 is a flow chart of a method for detecting a die disclosed in an embodiment of the present invention.

Figure 5 is a schematic illustration of an image of a standard die according to the present invention.

Figure 6 is a schematic diagram of an image of a crystal to be tested according to the present invention.

Figure 7 is a schematic diagram of an image of a die to be tested according to the present invention.

Figure 8A is a schematic diagram of an image of a standard die according to the present invention.

Figure 8B is a schematic diagram of an image of a die to be tested according to the present invention.

Figure 8C is a schematic view of a defect area of a die to be tested according to the present invention.

Figure 9 is a graph showing the results of grain inspection disclosed in an embodiment of the present invention.

In order to make the description of the present invention more detailed and complete, reference is made to the description of the following embodiments and the accompanying drawings. However, the examples shown below are intended to exemplify the light-emitting elements of the present invention, and the present invention is not limited to the following examples. Further, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the present specification are not limited to the description, and the scope of the present invention is not limited thereto, and is merely illustrative. Further, the size, positional relationship, and the like of the members shown in the drawings may be exaggerated for clarity of explanation. Further, in the following description, in order to omit the detailed description, the same or similar members are denoted by the same names and symbols.

A photovoltaic element, such as a light-emitting diode, is fabricated by a wafer through a coating process in a front-end process, a yellow lithography process, and then a dicing step to form a plurality of individual dies. The plurality of independent dies are sorted according to the customer's or user's specifications, and after a series of die inspections, the dies that do not meet the customer's or user's specifications are sorted out. In one embodiment of the invention, the wafer includes a gallium arsenide (GaAs) wafer for growing aluminum gallium indium arsenide (AlGaInP) or sapphire (Al _{2 for} growing indium gallium nitride (InGaN). O ₃ ) wafers, gallium nitride (GaN) wafers or tantalum carbide (SiC) wafers, or germanium wafers, germanium wafers, or gallium arsenide wafers used to grow III-V solar cell stacks . A semiconductor having photoelectric properties can be formed on the wafer by metalorganic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydride vapor deposition (HVPE), evaporation or ion plating. A laminate, such as a light-emitting laminate or a photovoltaic laminate. After the wafer epitaxy is completed, the electrode is formed by an evaporation process, and then a yellow light, an etching process is formed to form a dicing street, and finally a dicing or laser cutting step is performed along the scribe line to separate the crystal grains from each other, that is, to form A plurality of independent grains.

According to the above, after the wafer is cut to form a plurality of independent crystal grains, this A plurality of independent dies may be attached to a die carrying portion, wherein the die carrying portion may be a viscous or ductile adhesive, such as a blue film tape or an ultraviolet tape, in an embodiment of the present invention The middle is to use blue film tape as the grain bearing part. The cutting step described above may also be performed after the wafer is attached to the die carrying portion. Fig. 1 is a schematic view of a crystal grain detecting apparatus 1 disclosed in an embodiment of the present invention. As shown in FIG. 1 , taking a single die to be tested as an example, the die detecting device 1 includes a first die 3b to be tested and a die carrying portion 2 to carry the first die 3b to be tested, wherein A die 3b to be tested includes a lower surface S1, an upper surface S3, and a side surface S2. The grain detecting device 1 includes A back light device 100 and a forward light device 110 are detected to detect grain defects, wherein the back light device 100 is located below the die carrier 2 and the forward light device 110 is located above the die carrier 2. The back light device 100 includes a first light source 14 that emits a first light 141, and a second light source 13 that emits a second light 131, which is located below the first die 3b. Below, wherein the first light 141 is incident on the first die 3b at an oblique angle, and the second light 131 is substantially perpendicularly incident on the first die 3b, in other words, the angle at which the second light 131 is incident on the lower surface S1. Less than the angle at which the first light ray 141 is incident on the lower surface S1. Specifically, the first light ray 141 is at an oblique angle, partially incident on the lower surface S1, partially incident on the side surface S2, and the second light ray 131 is substantially perpendicularly incident on the lower surface S1. The forward light device 110 includes a third light source 15 that emits a third light 151, and is disposed above the first die 3b, and a fourth light source 12 that emits a fourth light 121 is located at the first die 3b. Above, wherein the fourth light 121 is incident on the first die 3b at an oblique angle, and the third light 151 is substantially perpendicularly incident on the first die 3b, in other words, the angle of the third light 151 is incident on the upper surface S3. Less than the angle at which the fourth ray 121 is incident on the upper surface S3. The die detecting device 1 includes a photosensitive element 11 located above the first die 3b to be collected to collect the first light 141, the second light 131, the third light 151, or the third light 151, or the first light ray 151, or The fourth light ray 121. In an embodiment of the invention, the first light source 14, the second light source 13, the third light source 15, or the fourth light source 12 is a pulsed xenon flash lamp. The first light source 14 or the fourth light source 12 is an annular structure having a central aperture.

As shown in FIG. 1, in one embodiment of the present invention, the first die 3b to be tested includes a substrate 36, a semiconductor laminate 30 is disposed on one side of the substrate 36, and an electrode structure 35b is located on the semiconductor laminate. 30 above the surface S3. The substrate 36 may be a sapphire substrate or a III-V semiconductor substrate. The semiconductor stack 30 includes a first type semiconductor layer 31, a second type semiconductor layer 32, and an active layer 33 between the first type semiconductor layer 31 and the second type semiconductor layer 32. The first type semiconductor layer 31 and the second type semiconductor layer 32, for example, a cladding layer or a confinement layer, respectively provide electrons and holes, and the electrons and holes are actively driven by a current. Layer 33 is composited to emit a light. The material of the semiconductor stack 30 comprises a III-V semiconductor material, such as Al _x In _y Ga _(1-xy) N or Al _x In _y Ga _(1-xy) P, where 0 ≦ x, y ≦ 1; (x +y)≦1. Depending on the material of the active layer 33, the semiconductor stack 30 can emit red light having a wavelength between 610 nm and 650 nm, green light having a wavelength between 530 nm and 570 nm, or blue light having a wavelength between 450 nm and 490 nm. In one embodiment of the present invention, the first die 3b to be tested includes a reflective structure 34 on the other side of the substrate 36, that is, under the first die 3b to be tested. On the surface S1, wherein the reflective structure 34 is a single layer or a multilayer structure, such as a Distributed Bragg Reflector (DBR), the material of the reflective structure 34 comprises a metal, a metal oxide, an oxide, a nitride, an oxynitride or the like. Any combination of materials. The first die to be tested 3b has a height between 50 μm and 200 μm.

2A is a top view of an electrode structure 35a of a standard crystal 3a according to an embodiment of the present invention. 2B is a partial schematic view of a die detecting apparatus according to an embodiment of the present invention. As shown in FIG. 2B, part of the first light ray 141 is reflected by the reflective structure 34 when it is incident on the lower surface S1 of the standard crystal grain 3a; part of the first light ray 141 Then, the standard crystal grain 3a is incident via the side surface S2 of the standard crystal grain 3a, and then penetrates the substrate 36 and the semiconductor laminate 30, and is emitted by covering the upper surface S3 without the electrode structure 35a. That is, when the first light ray 141 is incident on the standard crystal grain 3a via the side surface S2, part of the first light ray 141 fails to penetrate the electrode structure 35a and enters the photosensitive element 11 of FIG. 1, thus forming a dark region. a portion of the first light 141 penetrates the upper surface S3 not covered by the electrode structure 35a and enters the photosensitive element 11 of FIG. 1, thereby forming a bright area, and then combining the dark area and the bright area through a computer The soft body processing constitutes a reference image of the electrode structure 35a shown in Fig. 2A. FIG. 3A is a top view of an electrode structure 35b of the die 3b to be tested disclosed in an embodiment of the present invention. FIG. 3B is a partial schematic view of a die detecting apparatus according to an embodiment of the present invention. As shown in FIG. 3A, when the electrode structure 35b includes a defect 351, such as a broken line, the first light ray 141 can penetrate the defect 351, enter the photosensitive element 11 of FIG. 1 without being shielded by the electrode structure 35b, and then The above method constitutes a test image according to the electrode structure 35b shown in Fig. 3A, and the test image is taken to compare the difference in pattern or shape with the reference image, thereby detecting the defect of the electrode structure 35b in Fig. 3A. However, the type of the defect is not limited by the defect of the electrode structure, and any defect formed on the surface of the first die 3b to be tested can be detected by the method and apparatus.

Figure 4 is a flow chart of a method for detecting a grain according to an embodiment of the present invention.

First, a die to be tested, such as the first die 3b to be tested shown in FIG. 1 or FIG. 3B, is provided. Then, a die carrying portion 2 is provided to carry the die to be tested, and a light source required for detecting the die to be tested is provided. As shown in Figure 1, the offer can be issued first The first light source 14 of the light 141, such as a pulsed xenon flash lamp, is located below the first die 3b to be tested, and a portion of the first light 141 can penetrate the die carrying portion 2 via the side of the first die 3b to be tested. The surface S2 is incident on the first die 3b to be tested, and a portion of the first ray 141 is incident on the first die 3b to be tested via the lower surface S1 of the first die 3b to be tested. Specifically, the first light 141 can penetrate the substrate 36 of the first die 3b to be tested and the semiconductor laminate 30. When the first die 3b to be tested has the reflective structure 34, the first die 3b is reflected. The structure 34 can reflect a portion of the first light 141 that is directed toward the lower surface S1 of the first die 3b to be tested.

Next, the grain detecting device 1 shown in FIG. 1 is used to collect the crystal to be measured. An image of the grain. Referring to FIG. 5, an image of another die 5 to be tested is collected by the die detecting device 1 according to the present invention. The die 5 to be tested includes an electrode pad 50 and a semiconductor stack 51. Referring to FIG. 6 , an image of another die 6 to be tested is collected by the die detecting device 1 , wherein the die 6 to be tested includes an electrode pad 60 and a semiconductor stack 61 .

Second, an image of one of the standard dies is provided. Please refer to Figure 7 for this Another image of a standard die 7 is invented, wherein the standard die 7 comprises an electrode pad 70 and a semiconductor stack 71.

Secondly, a first determining step is provided to compare whether there is a color difference between the image color of the die to be tested and the image color of the standard die, and whether the difference of the color difference exceeds a standard, such as a customer tolerance range, if the color difference is within the customer's allowable range It is judged to be a good product, and if the difference in color difference is outside the allowable range of the customer, it is judged to be a defective product. Once judged as defective, the image color of the die to be tested and the image of the standard grain The position where the color difference of the color exceeds the standard is defined as a defect position. For example, comparing the image color of the die 5 to be tested with the image color of the standard die 7, as shown in FIG. 5, the semiconductor stack 51 of the die 5 to be tested and the semiconductor stack 71 of the standard die 7 are not. The chromatic aberration is different, and the electrode pad 50 of the die 5 to be tested has a color difference difference from the electrode pad 70 of the standard die 7, and if the chromatic aberration difference is within the allowable range of the customer, it is judged that the die 5 to be tested is a good product. For example, comparing the image color of the die 6 to be tested with the image color of the standard die 7, as shown in FIG. 6, there is no difference in color difference between the electrode pad 60 of the die 6 to be tested and the electrode pad 70 of the standard die 7. The semiconductor stack 61 of the die 6 to be tested has a difference in color difference from the semiconductor stack 71 of the standard die 7. If the difference in color difference is outside the allowable range of the customer, it is judged that the die 6 to be tested is a defective product, and the die to be tested is After the determination of the defective product, the position difference between the image color of the die 6 to be tested and the image color of the standard crystal grain 7 exceeds the standard is defined as a defect position.

Secondly, a second determining step is provided, wherein the second determining step comprises whether the size of the defect measured in the defect position defined in the first determining step exceeds a standard, and if the size of the defect is within the tolerance of the customer, it is judged as a good product, if the defect The size is judged to be a defective product outside the allowable range of the customer. Take the die 6 to be tested as an example. 8A is an image 71a of a portion of the semiconductor stack 71 of the standard die 7, and FIG. 8B is an image 61a of a portion of the semiconductor stack 61 of the die 6 to be tested, by comparing the image 61a with the image 71a. It is detected that the image 61a of the detecting die 6 has a color difference from the image 71a of the standard die 7, and the position where the difference in color difference is defined is a defect position, and has a defect image 61b as shown in FIG. 8C. If the defect image 61b determines that the color difference is outside the allowable range of the customer in the first determining step, then further In the second determination step, it is determined whether the size of the defective image 61b is outside the allowable range of the customer, and if the size of the defective image 61b is within the allowable range of the customer, it is judged to be a good product, and if the size of the defective image 61b is outside the allowable range of the customer, it is determined to be a defective product.

Then, by moving the platform of one of the load bearing die carriers 2 (not shown), the die detecting method of FIG. 4 is repeated to detect other die to be tested.

Fig. 9 is a view showing the result of grain inspection of the crystal grain detecting apparatus disclosed in an embodiment of the present invention. A plurality of crystal grains 3 are located on the crystal grain carrying portion 2, and the crystal grains 3 are separated from each other and surrounded by a plurality of scribe lines d, wherein the cutting track d has a width D so that the first pattern is A back side light of the die detecting device 1 , for example, the first light ray 141 , can penetrate the die carrying portion 2 and enter the side surface of the die 3 (not shown), for example, the side of the first die 3b to be tested. Surface S2. The die detecting method of FIG. 4 is repeated in a linear traveling direction, for example, the first direction 7a or the second direction 7b, by moving a platform (not shown) of the carrier die bearing portion 2. As shown in FIG. 9, a plurality of crystal grains 3 can be sorted out of a customer's allowable range, such as a die 3a, via the die detecting device 1 shown in FIG. 1 and the die detecting method of FIG. Pick up defective products outside the customer's tolerance, such as die 3b.

The above figures and descriptions are only corresponding to specific embodiments, however, the elements, embodiments, design criteria, and technical principles described or disclosed in the various embodiments are inconsistent, contradictory, or difficult to implement together. In addition, we may use any reference, exchange, collocation, coordination, or merger as required.

Although the invention has been described above, it is not intended to limit the scope of the invention, the order of implementation, or the materials and process methods used. For each of the inventions Modifications and variations are possible without departing from the spirit and scope of the invention.

3b‧‧‧First die to be tested

2‧‧‧Grade carrier

30‧‧‧Semiconductor laminate

31‧‧‧First conductive semiconductor layer

32‧‧‧Second conductive semiconductor layer

33‧‧‧ active layer

34‧‧‧Reflective structure

35b‧‧‧electrode structure

351‧‧‧Defect location

36‧‧‧Substrate

14‧‧‧First light source

141‧‧‧First light

S1‧‧‧ lower surface

S2‧‧‧ side surface

S3‧‧‧ upper surface

Claims (10)

A method for detecting a die includes: providing a first die to be tested, including a lower surface, a side surface, and an upper surface; and providing a first light source capable of emitting a first light to be located in the first die to be tested In the lower part, the first portion of the first light is incident on the first die to be tested through the side surface, and the other portion of the first light is incident on the first die to be tested through the lower surface, wherein the first die to be tested Further comprising a substrate, a semiconductor stack on one side of the substrate, an electrode structure on the semiconductor stack, and a reflective structure on the other side of the substrate, the reflective structure reflecting the first light The other part. The method for detecting a grain according to claim 1, further comprising providing a die carrying portion for carrying the first die to be tested, wherein a portion of the first light incident on the first die to be tested may be Penetrating the die carrier. A method for detecting a die includes: providing a first die to be tested; providing a first light source that emits a first light is located under the first die to be tested; and providing a photosensitive element in the first crystal to be tested Collecting a first light beam over a portion of the first die to be tested to obtain a test image of the first die to be tested; providing a reference image; comparing the color of the image to the color of the reference image To define a deficiency Trap; and measure the size of the defect. The method for detecting a grain according to claim 1, further comprising providing a second light source emitting a second light below the first die to be tested, wherein the second light is incident on the lower surface Less than the angle at which the first ray is incident on the lower surface. The method for detecting a grain according to claim 1, further comprising: providing a third light source capable of emitting a third light light over the first die to be tested; and providing a fourth light emitting The fourth light source is located above the first die to be tested, wherein an angle at which the third light is incident on the upper surface is smaller than an angle at which the fourth light is incident on the upper surface. The method for detecting a grain according to claim 1, further comprising providing a photosensitive element above the first die to be collected to collect the first light that penetrates the first die to be obtained. An image of one of the crystals to be measured. The method for detecting a grain according to claim 6, wherein the first light source is an annular structure, and the photosensitive element collects the first light through an aperture of the annular structure. The method for detecting a grain according to claim 6, further comprising: providing a first determining step, wherein the first determining step comprises providing an image of a standard die, and comparing the first die to be tested The color of the image and the color of the image of the standard die define a defect. The method for detecting a grain according to claim 8, further comprising: providing a second determining step, wherein the second determining step comprises measuring a size of the defect. The method for detecting a grain according to claim 1, further comprising providing a second die to be tested on the die carrying portion, wherein the first die to be tested and the second die to be tested Separated by a distance.