Manufacturing method of semiconductor structure

Abstract

The invention provides a manufacturing method of a semiconductor structure, and the method comprises the steps: firstly cutting a substrate to form a plurality of mutually independent chips to be bonded, and enabling each chip to be bonded to comprise a pixel structure and a part of substrate formed through cutting, and bonding each chip to be bonded with the corresponding driving structure on the driving substrate in a one-to-one correspondence manner. Therefore, on one hand, the arrangement of the to-be-bonded chips on the substrate is irrelevant to the arrangement of the driving structure, so that the to-be-bonded chips on the substrate can be arranged more densely, the pixel structure material is saved, and the utilization rate of the pixel structure material is further improved; and on the other hand, the size of the driving substrate is irrelevant to the size of the substrate where the pixel structure is located, so that the driving substrate comprises more driving circuits, and the utilization rate of the material of the driving substrate is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor device preparation, and in particular to a method for manufacturing a semiconductor structure. Background Art

[0002] In the process of making micro LED AR chips, it is necessary to bond the LED chips to the driving circuits on the CMOS substrate. However, on the one hand, since the size of the substrate where the LED chip is located is smaller than that of the CMOS substrate, it is usually necessary to cut the CMOS substrate into the same size as the substrate where the LED chip is located before bonding it to the substrate where the chip is located, which will lead to a waste of CMOS substrate materials; on the other hand, since the spacing between several driving circuits in the CMOS substrate is large, this will lead to a waste of LED chip materials. Summary of the invention

[0003] The present invention provides a method for manufacturing a semiconductor structure to solve the problem that both LED chip materials and CMOS substrate materials are wasted in the process of manufacturing a micro LED AR chip.

[0004] According to the present invention, there is provided a method for manufacturing a semiconductor structure, comprising:

[0005] Providing a driving substrate, the driving substrate comprising a plurality of driving circuits distributed at intervals, and a surface of the driving substrate having a plurality of driving structures corresponding to the driving circuits one by one;

[0006] Providing a substrate, and forming a plurality of pixel structures on the substrate;

[0007] Cutting the substrate to form a plurality of chips to be bonded, each chip to be bonded includes a pixel structure and a portion of the substrate formed by the cutting, and the pixel structure and the portion of the substrate overlap;

[0008] Placing a plurality of the chips to be bonded on a plurality of the driving structures in sequence, wherein the chips to be bonded correspond to the driving structures one by one, and the pixel structure is located between the driving structure and the part of the substrate;

[0009] After placing the plurality of chips to be bonded on the plurality of driving structures in sequence, bonding the chips to be bonded to the corresponding driving structures;

[0010] After the chip to be bonded is bonded to the corresponding driving structure, the portion of the substrate in the chip to be bonded is peeled off.

[0011] Optionally, the method of placing the plurality of chips to be bonded on the plurality of driving structures in sequence includes:

[0012] Inspecting the plurality of chips to be bonded by automatic optical inspection to obtain a plurality of chips to be bonded that have no defects in appearance;

[0013] The chips to be bonded that have no defects in appearance are placed on the plurality of driving structures in sequence.

[0014] Optionally, the process method of placing the chips to be bonded on the blue film that have no defects in appearance on the plurality of driving structures in sequence is a pick-and-place process.

[0015] Optionally, the substrate is a sapphire substrate, and the process of stripping the portion of the substrate in the chip to be bonded is chemical stripping.

[0016] Optionally, the process of bonding the chip to be bonded to the corresponding driving structure includes thermal compression bonding.

[0017] Optionally, the pixel structure includes an epitaxial layer, a metal reflective layer and a metal bonding layer, and the method of forming a plurality of pixel structures on the substrate includes:

[0018] growing an epitaxial layer on the substrate;

[0019] Cutting the epitaxial layer to form a plurality of epitaxial units distributed at intervals on the substrate;

[0020] A metal reflective layer and a metal bonding layer are sequentially formed on each of the epitaxial units.

[0021] Optionally, the method for growing an epitaxial layer on the substrate includes: sequentially forming an N-type semiconductor layer, a light-emitting layer, and a P-type semiconductor layer on the substrate.

[0022] Optionally, the driving structure includes an insulating layer and a plurality of first electrodes located in the insulating layer, the plurality of first electrodes are independent of each other, and the first electrodes penetrate the insulating layer.

[0023] Optionally, also include:

[0024] After peeling off the part of the substrate in the chip to be bonded, each of the pixel structures is etched to divide each of the pixel structures into a plurality of mutually independent pixel point structures, and the pixel point structures correspond to the first electrodes one by one.

[0025] Optionally, the first electrode is a P-type electrode.

[0026] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0027] In a method for manufacturing a semiconductor structure provided by an embodiment of the present invention, a plurality of independent chips to be bonded are formed by first cutting a substrate, each chip to be bonded includes a pixel structure and a portion of the substrate formed by cutting, and then each chip to be bonded is bonded one-to-one with the corresponding driving structure on the driving substrate. Therefore, on the one hand, the arrangement of the chips to be bonded on the substrate is independent of the arrangement of the driving structure, so that the chips to be bonded on the substrate can be arranged more densely, thereby saving pixel structure materials and further improving the utilization rate of pixel structure materials; on the other hand, the size of the driving substrate is independent of the size of the substrate where the pixel structure is located, so that the driving substrate includes a larger number of driving circuits, thereby improving the utilization rate of the driving substrate materials.

[0028] Furthermore, after automatic optical inspection, several chips to be bonded with no defects in appearance are bonded to the driving structure one by one, so that chips to be bonded with defects in appearance cannot be bonded to the driving structure, thereby improving the yield rate of product output.

[0029] Furthermore, the process of stripping part of the substrate in the chip to be bonded is chemical stripping. Therefore, on the one hand, since chemical stripping does not damage the pixel structure, the product yield can be further improved; on the other hand, since chemical stripping can strip part of the substrate in multiple chips to be bonded at one time, the production efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1-Figure 9 It is a schematic diagram of various steps in a method for manufacturing a semiconductor structure in one embodiment of the present invention.

[0031] Reference numerals:

[0032] 1- substrate;

[0033] 2- epitaxial layer;

[0034] 21-P type semiconductor layer;

[0035] 22-light emitting layer;

[0036] 23-N-type semiconductor layer;

[0037] 3- driving substrate;

[0038] 4-Metal reflector;

[0039] 5-metal bonding layer;

[0040] 6-blue film;

[0041] 7- Chip to be bonded;

[0042] 8- insulation layer;

[0043] 9- a first electrode;

[0044] 10-pixel structure;

[0045] 11- Driving structure. DETAILED DESCRIPTION

[0046] As described in the background art, in the process of manufacturing the micro LED AR chip, both the CMOS substrate material and the LED chip material are wasted.

[0047] Specifically, a method for bonding an LED chip to a driving circuit on a CMOS substrate comprises the following steps: providing a substrate; growing an epitaxial layer on the substrate; sequentially forming a reflective layer and a bonding layer on the epitaxial layer to form an initial LED chip; providing a CMOS substrate, the CMOS substrate comprising a plurality of drive circuits distributed at intervals; cutting the CMOS substrate into the same size as a second substrate; after cutting the CMOS substrate into the same size as the second substrate, bonding the bonding layer in the initial LED chip to one side of the CMOS substrate; after bonding the bonding layer in the initial LED chip to one side of the CMOS substrate, laser stripping the substrates in the plurality of initial LED chips; after laser stripping the second substrates in the plurality of initial LED chips, etching the epitaxial layer, the reflective layer and the bonding layer to form a plurality of independent LED chips, wherein the LED chips correspond one to one to the drive circuits in the CMOS substrate.

[0048] In view of this, the present invention creatively proposes a method for manufacturing a semiconductor structure, including: providing a driving substrate, the driving substrate including a plurality of driving circuits distributed at intervals, and a plurality of driving structures corresponding to the driving circuits are formed on the surface of the driving substrate; providing a substrate, and forming a plurality of pixel structures on the substrate; cutting the substrate to form a plurality of chips to be bonded, each chip to be bonded including a pixel structure and a portion of the substrate formed by the cutting, and the pixel structure and the portion of the substrate overlap; placing a plurality of chips to be bonded on a plurality of the driving structures in sequence, the chips to be bonded corresponding to the driving structures in a one-to-one manner, and the pixel structure being located between the driving structure and the portion of the substrate; after placing the plurality of chips to be bonded on the plurality of driving structures in sequence, bonding the chips to be bonded to the corresponding driving structures; after bonding the chips to be bonded to the corresponding driving structures, peeling off the portion of the substrate in the chips to be bonded.

[0049] By first cutting the substrate to form a number of independent chips to be bonded, each chip to be bonded includes a pixel structure and a part of the substrate formed by cutting, and then each chip to be bonded is bonded one-to-one with the corresponding driving structure on the driving substrate, thereby saving pixel structure materials, improving the utilization rate of pixel structure materials, and improving the utilization rate of driving substrate materials.

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the embodiments in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. The terms "first", "second", "third", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0051] Please refer to Figure 1 and Figure 2 , Figure 1 is a top view of a driving substrate in one embodiment of the present invention, Figure 2 yes Figure 1 A schematic cross-sectional structure diagram of a driving structure in a driving substrate is provided, wherein a driving substrate 3 is provided. The driving substrate 3 includes a plurality of driving circuits distributed at intervals, and a plurality of driving structures 11 corresponding to the driving circuits are formed on the surface of the driving substrate 3.

[0052] The driving substrate 3 includes a CMOS silicon substrate. Of course, there are many other options for the driving substrate 3, and the present invention does not limit this.

[0053] In this embodiment, the driving structure 11 includes an insulating layer 8 and a plurality of first electrodes 9 located in the insulating layer 8 . The plurality of first electrodes 9 are independent of each other, and the first electrodes 9 penetrate the insulating layer 8 .

[0054] Please refer to Figure 3 as well as Figure 4 , Figure 3 as well as Figure 4It is a cross-sectional schematic diagram of the steps of forming a plurality of pixel structures in one embodiment of the present invention. A substrate 1 is provided, and a plurality of pixel structures are formed on the substrate 1 .

[0055] The substrate 1 includes a sapphire substrate 1. Of course, there are many other options for the material of the substrate 1, and the present invention does not limit this.

[0056] In this embodiment, the pixel structure includes an epitaxial layer 2, a metal reflective layer 4 and a metal bonding layer 5, and a method of forming a plurality of pixel structures on a substrate 1 includes:

[0057] Growing an epitaxial layer 2 on a substrate 1;

[0058] Cutting the epitaxial layer 2 to form a plurality of epitaxial units spaced apart from each other on the substrate 1;

[0059] A metal reflective layer 4 and a metal bonding layer 5 are sequentially formed on each epitaxial unit.

[0060] The method for growing the epitaxial layer 2 on the substrate 1 includes: sequentially forming an N-type semiconductor layer 23 , a light emitting layer 22 and a P-type semiconductor layer 21 on the substrate 1 .

[0061] The material of the metal reflective layer 4 may be silver, for example, and the material of the metal bonding layer 5 is a high-density metal material, such as tungsten. Of course, there are many other materials for the metal reflective layer 4 and the metal bonding layer 5, and the present invention does not limit this.

[0062] Of course, there are many other options for pixel structure, and the present invention does not limit this.

[0063] Please refer to Figure 5 , Figure 5 It is a cross-sectional schematic diagram of a method for manufacturing a semiconductor structure in an embodiment of the present invention, wherein a substrate 1 is cut to form a plurality of chips 7 to be bonded, each chip 7 to be bonded includes a pixel structure and a portion of the substrate 1 formed by cutting, and a pixel structure and a portion of the substrate 1 overlap.

[0064] Before cutting the substrate 1, the substrate 1 needs to be placed on a blue film 6 to fix the substrate 1, thereby reducing the problems of the substrate 1 breaking, displacement and falling during the cutting process.

[0065] Among them, the plurality of chips 7 to be bonded are independent of each other, the area of ​​a portion of the substrate 1 in each chip 7 to be bonded is greater than or equal to the projection area of ​​the pixel structure on the substrate 1 , and the pixel structure overlaps with a portion of the substrate 1 .

[0066] Please refer to Figure 6 as well as Figure 7 , Figure 6is a top view of a plurality of chips to be bonded placed on a plurality of driving structures in an embodiment of the present invention, Figure 7 yes Figure 6 The cross-sectional structure diagram of a chip to be bonded is placed on a driving structure, and several chips to be bonded 7 are placed on several driving structures 11 in sequence, the chips to be bonded 7 correspond to the driving structures 11 one by one, and the pixel structure is located between the driving structure 11 and a part of the substrate 1.

[0067] Preferably, the method of sequentially placing a plurality of chips to be bonded 7 on a plurality of driving structures 11 comprises: inspecting a plurality of chips to be bonded 7 by automatic optical inspection, obtaining a plurality of chips to be bonded 7 with no defects in appearance, and then sequentially placing each chip to be bonded 7 with no defects in appearance on a plurality of driving structures 11. The automatic optical inspection can detect the chips to be bonded 7 with defects in appearance, and then remove the chips to be bonded 7 with defects in appearance, so that only the chips to be bonded 7 with no defects in appearance remain on the blue film 6, so that the chips to be bonded 7 with defects in appearance cannot be placed on the driving structure 11 for the next step, further improving the yield rate of product output.

[0068] Among them, before placing each chip 7 to be bonded with no defects in appearance on several driving structures 11 in sequence, several chips to be bonded with no defects in appearance need to be transferred to another blue film so that the pixel structure in the chip 7 to be bonded is located between part of the substrate 1 and the blue film.

[0069] Please refer to Figure 7 After placing a plurality of chips 7 to be bonded on a plurality of driving structures 11 in sequence, the chips 7 to be bonded are bonded to the corresponding driving structures 11 .

[0070] In this embodiment, a plurality of chips to be bonded 7 are uniformly bonded to a plurality of corresponding driving structures 11, thereby improving production efficiency.

[0071] In this embodiment, the process for bonding the chip to be bonded 7 and the corresponding driving structure 11 is thermal compression bonding.

[0072] Please refer to Figure 8 , Figure 8 It is a cross-sectional schematic diagram of a method for manufacturing a semiconductor structure in an embodiment of the present invention. After the chip 7 to be bonded is bonded to the corresponding driving structure 11, a portion of the substrate 1 in the chip 7 to be bonded is peeled off.

[0073] In one embodiment, the process of peeling off a portion of the substrate 1 in the chip to be bonded 7 is laser peeling.

[0074] Compared with laser stripping which is easy to cause damage to the pixel structure, the chemical stripping process is adopted in this embodiment. In particular, since the area of ​​the partial substrate 1 in the chip 7 to be bonded is small, the chemical stripping process can be adopted in this embodiment to strip the partial substrate 1 in the chip 7 to be bonded, and the chemical stripping can uniformly strip the partial substrates 1 in several chips 7 to be bonded without damaging the pixel structure in the chip 7 to be bonded, so that the production efficiency can be further improved.

[0075] In this embodiment, please refer to Fig. 9 , Fig. 9 It is a cross-sectional schematic diagram of a method for manufacturing a semiconductor structure in an embodiment of the present invention. After peeling off part of the substrate 1 in the chip 7 to be bonded, each pixel structure is etched to divide each pixel structure into a plurality of independent pixel point structures 10, and the pixel point structures 10 correspond one-to-one to the first electrode 9.

[0076] Since the P-type semiconductor layer 21 is electrically connected to the first electrode 9 through the metal reflective layer 4 and the metal bonding layer 5 , the first electrode 9 is a P-type electrode.

[0077] The process of etching the pixel structure includes dry etching or wet etching.

[0078] In summary, in a method for manufacturing a semiconductor structure provided by an embodiment of the present invention, a plurality of independent chips to be bonded are formed by first cutting the substrate, each chip to be bonded includes a pixel structure and a portion of the substrate formed by cutting, and then each chip to be bonded is bonded one-to-one with the corresponding driving structure on the driving substrate. Therefore, on the one hand, the arrangement of the chips to be bonded on the substrate is independent of the arrangement of the driving structure, so that the chips to be bonded on the substrate can be arranged more densely, thereby saving pixel structure materials and further improving the utilization rate of pixel structure materials; on the other hand, the size of the driving substrate is independent of the size of the substrate where the pixel structure is located, so that the driving substrate includes a larger number of driving circuits, thereby improving the utilization rate of the driving substrate materials.

[0079] Furthermore, after automatic optical inspection, several chips to be bonded with no defects in appearance are bonded to the driving structure one by one, so that chips to be bonded with defects in appearance cannot be bonded to the driving structure, thereby improving the yield rate of product output.

[0080] Furthermore, the process of stripping part of the substrate in the chip to be bonded is chemical stripping. Therefore, on the one hand, since chemical stripping does not damage the pixel structure, the product yield can be further improved; on the other hand, since chemical stripping can strip part of the substrate in multiple chips to be bonded at one time, the production efficiency can be improved.

[0081] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A method for manufacturing a semiconductor structure, characterized in that: include: Providing a driving substrate, the driving substrate comprising a plurality of driving circuits distributed at intervals, and a surface of the driving substrate having a plurality of driving structures corresponding to the driving circuits one by one; Providing a substrate, and forming a plurality of pixel structures on the substrate; Cutting the substrate to form a plurality of chips to be bonded, each chip to be bonded includes a pixel structure and a portion of the substrate formed by the cutting, and the pixel structure and the portion of the substrate overlap; Placing a plurality of the chips to be bonded on a plurality of the driving structures in sequence, wherein the chips to be bonded correspond to the driving structures one by one, and the pixel structure is located between the driving structure and the part of the substrate; After placing the plurality of chips to be bonded on the plurality of driving structures in sequence, bonding the chips to be bonded to the corresponding driving structures; After the chip to be bonded is bonded to the corresponding driving structure, the portion of the substrate in the chip to be bonded is peeled off.

2. The method for manufacturing a semiconductor structure according to claim 1, characterized in that: The method of placing the plurality of chips to be bonded on the plurality of driving structures in sequence comprises: Inspecting the plurality of chips to be bonded by automatic optical inspection to obtain a plurality of chips to be bonded that have no defects in appearance; The chips to be bonded that have no defects in appearance are placed on the plurality of driving structures in sequence.

3. The method for manufacturing a semiconductor structure according to claim 2, characterized in that: The process of placing the chips to be bonded on the blue film with no defects in appearance on the plurality of driving structures in sequence is a pick and place process.

4. The method for manufacturing a semiconductor structure according to claim 1, characterized in that: The substrate is a sapphire substrate, and the process for stripping the portion of the substrate in the chip to be bonded is chemical stripping.

5. The method for manufacturing a semiconductor structure according to claim 1, characterized in that: The process of bonding the chip to be bonded to the corresponding driving structure includes thermal compression bonding.

6. The method for manufacturing a semiconductor structure according to claim 1, characterized in that: The pixel structure includes an epitaxial layer, a metal reflective layer and a metal bonding layer, and the method of forming a plurality of pixel structures on the substrate includes: growing an epitaxial layer on the substrate; Cutting the epitaxial layer to form a plurality of epitaxial units distributed at intervals on the substrate; A metal reflective layer and a metal bonding layer are sequentially formed on each of the epitaxial units.

7. The method for manufacturing a semiconductor structure according to claim 6, characterized in that: The method for growing an epitaxial layer on the substrate comprises: sequentially forming an N-type semiconductor layer, a light-emitting layer and a P-type semiconductor layer on the substrate.

8. The method for manufacturing a semiconductor structure according to claim 7, characterized in that: The driving structure includes an insulating layer and a plurality of first electrodes located in the insulating layer, the plurality of first electrodes are independent of each other, and the first electrodes penetrate the insulating layer.

9. The method for manufacturing a semiconductor structure according to claim 8, characterized in that: Also includes: After peeling off the part of the substrate in the chip to be bonded, each of the pixel structures is etched to divide each of the pixel structures into a plurality of mutually independent pixel point structures, and the pixel point structures correspond to the first electrodes one by one.

10. The method for manufacturing a semiconductor structure according to claim 9, characterized in that: The first electrode is a P-type electrode.

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