TGV glass wafer via filling process and glass wafer

Abstract

The application discloses a TGV glass wafer via filling process, which is characterized in that a deep-width ratio is reduced in design, filling difficulty is reduced, and TGV interconnection of a relatively thick glass wafer can be realized; a glue coating layer is used as a buffer layer, a plurality of via structures are formed through etching treatment, and a conductive column in the via is used as a pin to connect an interconnection layer, so that an intermittently distributed interconnection layer is formed, the use volume of the conductive interconnection layer is reduced, the thermal expansion amount is small at high temperature, the glue material of the intermittent part can also play a buffering role, in addition, the contact part is connected through a plurality of conductive columns, the possibility of conduction is increased, and the stability of the device is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor electroplating processing, in particular to a TGV glass wafer via filling process and a glass wafer. BACKGROUND

[0002] In recent years, with the vigorous rise of emerging fields such as 5G, wearable devices, smart phones, automotive electronics, artificial intelligence, integrated circuit applications are developing towards diversified applications, and advanced three-dimensional packaging technology has gradually become an important means to realize the miniaturization, lightweight and multifunctionalization of electronic products. The application of some new materials and new technologies brings opportunities for packaging miniaturization, such as flexible substrates, through silicon via (TSV) adapter board technology and through glass via (TGV) adapter board technology have become one of the hot research directions of vertical 3D interconnection.

[0003] Glass materials and ceramic materials have no free-moving charges, excellent dielectric properties, and a thermal expansion coefficient close to silicon. The through glass via (TGV) technology using glass instead of silicon material can avoid the problem of poor insulation of TSV, and is an ideal three-dimensional integration solution. Through glass via (TGV) technology is considered to be the key technology of the next generation of three-dimensional integration, and the core of this technology is the deep hole forming process. However, there are several difficulties in the TGV filling process: currently, TGV needs to fill metal into the via, and then use CMP chemical mechanical polishing technology to remove the metal layer on the surface of the via to achieve via filling planarization.

[0004] (1) The high aspect ratio via filling requires high equipment and high chemical requirements for the seed layer. In addition, due to the large difference in thermal expansion coefficient between glass and metal, thermal stress problems caused by thermal mismatch, poor device stability, and performance degradation or even functional failure of the chip during operation;

[0005] (2) Currently, TGV filling on the market mainly has two types of profile and filling. It is difficult to fill high aspect ratio TGV vias, and the profile angle is large. If the angle reaches 90 degrees, stress concentration at the corner position is easy to cause the via to crack during temperature cycling, causing failure problems. SUMMARY

[0006] In view of the problems in the above technical background, one object of the present application is to provide a TGV glass wafer via filling process.

[0007] In order to achieve the above object, the technical scheme adopted by the present application is:

[0008] A TGV glass wafer via filling process, comprising the following steps:

[0009] S1, cleaning the glass wafer 150-1000 μm to make TGV communication hole;

[0010] S2, modifying the through hole, 20 μm diameter via hole, depth 150-1000 μm;

[0011] S3, modifying the through hole, 50-200 μm diameter via hole, depth 1 / 4-3 / 4 of the glass wafer thickness, forming a counterbore;

[0012] S4, using HF or high temperature alkali process, wet etching to form a trumpet-shaped counterbore;

[0013] S5, filling a metal adhesion layer on the side wall and bottom surface of the TGV communication hole and the upper surface of the glass wafer, thickness less than 2 μm;

[0014] S6, filling a conductive layer on the side wall and bottom of the TGV communication hole;

[0015] S7, coating a resin material with photosensitive properties on the upper part of the counterbore of the TGV communication hole to form a glue coating layer;

[0016] S8, exposure;

[0017] S9, development, etching, filling conductive material, forming an interconnection layer through the pin connected to the conductive layer.

[0018] Further, step S9, forming a single via hole through development and etching, filling conductive material in the via hole to the surface of the glue coating layer, forming an interconnection layer connected to the conductive layer through a single conductive column.

[0019] Further, step S9, forming multiple via holes of different sizes through development and etching, filling conductive material in the via hole corresponding to the counterbore to the surface of the glue coating layer, forming an interconnection layer connected to the conductive layer through multiple conductive columns.

[0020] Further, further including CMP: after forming multiple via holes of different sizes through development and etching, polishing and planarizing using CMP, filling conductive material in the via hole to the surface of the glue coating layer, forming an interconnection layer level with the upper surface of the glass wafer.

[0021] Further, in step S2 or S3, laser modification of the via hole, or mechanical processing, laser processing, sandblasting drilling or etching.

[0022] Further, in step S4, 6%-30% HF solution at room temperature or 30%-50% NaOH solution at 80-120°C.

[0023] Further, in step S5, the metal adhesion layer material is one or more of Cu, Ni, Ta, Ti, Pt, Pd, AlN or TiN.

[0024] Further, in step S6, the conductive layer material is one of conductive metal, metal mixture, carbon nanotube or multi-layer silicon material, and is prepared by electroplating, electroless plating, physical deposition, chemical vapor deposition or liquid metal.

[0025] Another object of the present application is to provide a TGV glass wafer prepared by the method as described above, comprising a glass wafer, a through-horn-shaped counterbore, a metal adhesion layer, a conductive layer, a glue coating layer and a conductive interconnection layer filled in the counterbore in sequence, and a plurality of conductive columns arranged in the glue coating layer and connecting the conductive layer and the conductive interconnection layer.

[0026] Further, a plurality of through holes are arranged in the glue coating layer, the through holes extend to the conductive layer, and the conductive columns are filled with conductive material in the through holes.

[0027] Compared with the prior art, the present application has the following advantages:

[0028] 1. The present application reduces the difficulty of filling the high aspect ratio through hole by modifying the through hole to form a counterbore, thereby reducing the aspect ratio and the difficulty of filling.

[0029] 2. The present application can realize TGV interconnection of a thick glass wafer by using the process, and the counterbore structure can overcome the defect of large profile.

[0030] 3. The present application uses the glue coating layer as a buffer layer, forms a plurality of through hole structures by etching treatment, and uses the conductive columns in the through holes as pins to connect the interconnection layer, thereby forming an intermittently distributed interconnection layer, reducing the volume of the conductive interconnection layer, and reducing the thermal expansion amount at high temperature. In addition, the contact part is connected by a plurality of conductive columns, which increases the possibility of conduction and can satisfy the interconnection of different line widths from small to large, thereby improving the stability of the device. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The flow chart of the TGV glass wafer through hole filling process of the present application is shown in the figure.

[0032] Figure 2 The flow chart of the filling process in an embodiment of the present application is shown in the figure.

[0033] Figure 3The flow chart of the filling process in another embodiment of the present application;

[0034] Figure 4 The filled product diagram of the present application.

[0035] Wherein, 1, glass wafer; 2, counterbore; 3, metal adhesion layer; 4, conductive layer; 5, glue coating layer; 6, conductive column; 7, conductive interconnection layer; 8, through hole. DETAILED DESCRIPTION

[0036] The specific embodiments of the present application are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0037] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0038] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "provided with", "connection" and the like should be broadly understood, for example, "connection" can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] As shown in Figures 1-4 A TGV glass wafer through hole filling process, comprising the following steps:

[0040] S1, cleaning the glass wafer 150-1000 μm, making TGV communication hole, as shown in Figure 1 (a);

[0041] S2, through hole modification, using laser modification through hole, or mechanical processing, laser processing, sand blasting drilling or etching, 20 μm diameter via, depth 150-1000 μm, as shown in Figure 1 (b);

[0042] S3, laser modification of via, or mechanical, laser, sandblasting drilling or etching, 50-200 μm diameter via, depth of 1 / 4-3 / 4 of the thickness of the glass wafer, forming a counterbore, as shown in Figure 1 (c);

[0043] S4, wet etching using HF or high temperature alkali process (NaOH, 120°C), forming a trumpet-shaped counterbore, as shown in Figure 1 (d);

[0044] S5, filling the metal adhesion layer 3 on the side wall and bottom surface of the TGV communication hole and the upper surface of the glass wafer, as shown in Figure 1 (e); thickness less than 2 μm, metal adhesion layer material is one or several of Cu, Ni, Ta, Ti, Pt, Pd, AlN or TiN;

[0045] S6, filling the conductive layer 4 on the side wall and bottom of the TGV communication hole, as shown in Figure 1 (f); conductive layer material is one of conductive metal, metal mixture, carbon nanotube or multi-layer silicon material, using electroplating, chemical plating, physical deposition, chemical vapor deposition or liquid metal;

[0046] S7, coating the upper part of the counterbore of the TGV communication hole with a resin material with photosensitive properties to form a glue coating layer 5, as shown in Figure 1 (g);

[0047] S8, exposure;

[0048] S9, development, etching, filling conductive material, forming interconnection layer 7 through the pin connected with the conductive layer 4, as shown in Figure 1 (h-1).

[0049] As shown in Figure 1 (h-1), in an embodiment of the present application:

[0050] Step S9, forming a single via through development and etching, filling conductive material in the via 8 to the surface of the glue coating layer 5, forming the interconnection layer 7 connected with the conductive layer 4 through a single conductive column 6.

[0051] As shown in Figure 2 , in another embodiment of the present application:

[0052] Step S9, forming multiple vias 8 of different sizes through development and etching, as shown in Figure 2 (h-2);

[0053] Filling conductive material in the via 8 corresponding to the counterbore 2 to form a conductive column, as shown in Figure 2 (i-1);

[0054] The conductive material is filled to the surface of the glue layer 5, and the interconnection layer 7 is formed by the plurality of conductive columns 6 in communication with the conductive layer 4, as shown in Figure 2 (j).

[0055] As shown in Figure 3 In another embodiment of the present application:

[0056] The plurality of through holes 8 of different sizes are formed by developing and etching, as shown in Figure 3 (h-2);

[0057] The CMP is used for polishing and planarization, as shown in Figure 3 (i-2), the conductive material is filled to the surface of the glue layer 5, and the interconnection layer 7 is formed in horizontal with the upper surface of the glass wafer 1, as shown in Figure 3 (k).

[0058] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements fall within the scope of the claimed present application. The scope of protection required by the present application is defined by the appended claims and their equivalents.

Claims

1. A via-hole filling process for TGV glass wafers, characterized in that, Includes the following steps: S1. Clean the glass wafer; S2, through-hole modification, 20μm diameter through-hole, depth of 150~1000μm; S3, through-hole modification, 50-200μm diameter through-holes, with a depth of 1 / 4 to 3 / 4 of the glass wafer thickness, forming countersunk holes; S4. Use HF or high-temperature alkaline process for wet etching to form a funnel-shaped TGV connecting hole; S5. Fill the sidewalls, bottom surface and upper surface of the TGV connecting hole with a metal adhesive layer with a thickness of less than 2μm. S6. Fill the sidewalls of the TGV connecting hole and the bottom of the countersunk hole with a conductive layer; S7. Coat the upper part of the countersunk hole of the TGV connecting hole with a photosensitive resin material to form a coating layer. S8, Exposure; S9. Develop and etch the adhesive layer, fill it with conductive material, and form an intermittently distributed interconnect layer through the pins connected to the conductive layer. In step S9, multiple through holes of different sizes are formed by developing and etching. Conductive material is filled into the through holes corresponding to the countersunk holes to the surface of the adhesive layer. The formed interconnect layer is connected to the conductive layer through multiple conductive pillars.

2. The TGV glass wafer through-hole filling process according to claim 1, characterized in that, It also includes CMP: after forming multiple through holes of different sizes through development and etching, CMP is used to polish and planarize them, and then conductive material is filled into the through holes to the surface of the adhesive layer, forming an interconnect layer that is horizontal with the upper surface of the glass wafer.

3. The TGV glass wafer through-hole filling process according to claim 1, characterized in that, In step S2 or S3, laser modification of the through hole is used.

4. The TGV glass wafer through-hole filling process according to claim 1, characterized in that, Step S4 involves treating with 6%~30% HF solution at room temperature or with 30%~50% NaOH solution at 80℃~120℃.

5. The TGV glass wafer through-hole filling process according to claim 1, characterized in that, Step S5: The metal adhesion layer material is one or more of Cu, Ni, Ta, Ti, Pt, Pd, AlN, or TiN.

6. The TGV glass wafer through-hole filling process according to claim 1, characterized in that, Step S6: The conductive layer material is one of conductive metal, carbon nanotubes, or multilayer silicon material, and is applied by electroplating, electroless plating, physical deposition, or chemical vapor deposition.

7. A TGV glass wafer prepared using the process described in any one of claims 1-6, characterized in that, The device includes a glass wafer and a through-hole horn-shaped recess. The recess is filled sequentially with a metal adhesive layer, a conductive layer, a coating layer, and a conductive interconnect layer. The coating layer and the conductive interconnect layer are discontinuously distributed. Several independent conductive pillars are disposed inside the coating layer, and the conductive layer and the conductive interconnect layer are connected by the conductive pillars.

8. The TGV glass wafer according to claim 7, characterized in that, The adhesive coating layer has several through holes inside, which extend inward to the conductive layer. The through holes are filled with conductive material to form the conductive pillars.

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