TWM618739U - Wafer separation device - Google Patents

Abstract

A wafer separation device is suitable for separating a wafer from a temporary substrate to which it is joined. The device includes a carrier plate, a plurality of grooves, and a plurality of suction holes. The carrier tray is used to place the temporary substrate and the wafer to be separated, and has a top surface. Each groove is formed by two side walls extending downward from the top surface of the carrier plate and a bottom wall connecting the two side walls away from the top surface. The side walls of each groove and the top surface are defined together. The joint is at a lead angle. The suction holes are distributed on the bottom walls of the grooves, and can be used to pump air to the corresponding grooves. When the wafer to be separated is fixed on the carrier tray, since the grooves and the joints of the top surface form a lead angle, it can avoid the situation of scratching the wafer due to the excessively sharp angles of the joints happen.

Description

Wafer separation device

The present invention relates to a separation device, in particular to a separation device suitable for semiconductor wafers.

In the semiconductor industry, wafers are gradually developing in the direction of volume miniaturization. At present, wafers can be thinned to hundreds of microns to tens of microns. In order to ensure that the wafer has sufficient mechanical support during the manufacturing process, while avoiding warping or deformation during the manufacturing process, or based on the requirements of the manufacturing process, the industry will attach a temporary substrate to the surface of the wafer, and then After the process is finished, the temporary substrate is separated from the wafer.

Referring to FIG. 1, in the process of separating a wafer 101 from a temporary substrate 102, a to-be-separated object (that is, a wafer 101 attached to the temporary substrate 102 with a crystal surface) is usually separated from the wafer 101. The crystal back direction of 101 is set on a chuck 103. A plurality of grooves 104 are formed on the surface of the carrier plate 103, and the bottoms of the grooves 104 are provided with a plurality of suction holes (not shown). When in use, the suction holes are used to pump air to the outside to make the inner space of the grooves 104 form a negative pressure state, and the wafer 101 can be sucked and fixed on the carrier plate 103. Generally, the wafer 101 and the temporary substrate 102 are bonded with wax having a melting point higher than 95° C. as a bonding layer (not shown). Therefore, subsequently, under a temperature condition (such as 150°C) at which the bonding wax can be softened or melted, a lateral thrust F is applied to the temporary substrate 102 to translate the temporary substrate 102 and push it out. The wafer 101 is separated. However, since the surface of the carrier plate 103 is at right angles to the junction I of the grooves 104, during the separation process, the right angle of the junction I of the carrier plate 103 and the wafer 101 is easy to scratch the The backside of the wafer 101 causes damage, which reduces the yield of the wafer detachment.

Therefore, the purpose of the present invention is to provide a wafer separation device to avoid damage to the wafer during the separation process.

Therefore, the novel wafer separation device is suitable for separating a wafer bonded on a temporary substrate from the temporary substrate, and includes a carrier plate, multiple grooves, and multiple suction holes.

The carrier plate has a top surface for placing the temporary substrate and the wafer to be separated.

Each groove is formed by two side walls extending downward from the top surface of the carrier plate and a bottom wall connecting the two side walls away from the top surface. The side walls of each groove and the top surface are defined together. The joint is at a lead angle.

The suction holes are distributed on the bottom walls of the grooves, and can be used to pump air to the corresponding grooves.

The effect of the present invention is: because the sidewalls of each groove and the top surface of the susceptor are at a lead angle, it prevents the periphery of the grooves from being in contact with the wafer due to the sharp angle of the joint. Scratch, which can improve the yield of wafer separation.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are represented by the same numbers.

Referring to FIGS. 2 and 3, a wafer separation device 200 of the present invention is suitable for separating a wafer 101 bonded on a temporary substrate 102 from the temporary substrate 102. Wherein, the temporary substrate 102 and the wafer 101 are bonded through a bonding material that can be removed under post-processing conditions, such as wax or rosin. In this embodiment, the temporary substrate 102 and the wafer 101 are bonded with wax (not shown) as an example. Therefore, subsequent heating can be used to melt/soften the wax to make the temporary substrate 102 Separate from the wafer 101.

The wafer separation device 200 includes a carrier plate 2, a plurality of grooves 3, a plurality of suction holes 4, and a coating layer 5.

The carrier plate 2 has a top surface 21 for placing the wafer 101 and the temporary substrate 102 to be separated.

The grooves 3 are formed on the carrier plate 2 and at least part of them communicate with each other. Each groove 3 is defined by two side walls 31 extending downward from the top surface 21 of the carrier plate 2 and a bottom wall 32 connecting the two side walls 31 at one end away from the top surface 21. Wherein, the junction between the sidewall 31 of each trench 3 and the top surface 21 forms a non-right-angled arc chamfering (Chamfering). Therefore, when the wafer 101 is placed on the carrier plate 2, the junction can be avoided The chip back is scratched due to sharp angles, or stress concentration occurs at the junction between the top surface 21 of the carrier plate 2 and the grooves 3, and the wafer 101 is scratched.

In addition, it should be noted that, in this embodiment, part of the grooves 3 are in a concentric ring shape, part of the grooves 3 are in a strip shape, and the strips of the grooves 3 are staggered in a concentric ring shape. The grooves 3 (see Fig. 2) are taken as an example. However, in actual implementation, the grooves 3 can be radially and/or concentrically ring-shaped, or distributed on the carrier plate 2 in other ways, and can be as required Different shapes such as strip, ring or arc, and each can be the same or different, and it is not limited to FIG. 2.

The suction holes 4 are distributed on the bottom wall 32 of at least a part of the groove 3 and communicate with the outside, and can be used to pump air to the corresponding groove 3. In some embodiments, the suction holes 4 may also be distributed on the sidewalls 31 of the grooves 3, as long as they can be used to pump the inner space of the grooves 3, and their distribution positions are not particularly limited.

The covering layer 5 covers at least the top surface 21 of the carrier plate 2, or can extend from the top surface 21 to cover the corners of the junctions of the grooves 3 and the top surface 21, or further Extending to the side walls 31 and bottom walls 32 of the grooves 3. In this embodiment, the covering layer 5 extends from the top surface 21 into the grooves 3 to cover the side walls 31 and the bottom wall 32 of the grooves 3, and make the suction The hole 4 is exposed as an example.

The cladding layer 5 is resistant to process temperature (higher than the temperature at which the bonding wax between the temporary substrate 102 and the wafer 101 is melted or softened), and is not easy to be separated from the wafer 101 to be separated or the ambient atmosphere (such as air Oxygen, moisture, etc.) in the wafer 101 are formed of polymer materials that react to contaminate the wafer 101. Preferably, the cladding layer 5 is made of a soft and high temperature resistant polymer material, so that the contact surface between the carrier plate 2 and the wafer 101 is soft, and can serve as the carrier plate 2 and the wafer 101 Stress buffer at the joint. More preferably, the cladding layer 5 is selected from high-temperature resistant and non-sticky fluorine-containing polymer materials, and is not easy to be softened or deteriorated due to the influence of the process temperature in the subsequent wafer separation process, or to stick impurities on surface.

In this embodiment, the cladding layer 5 is selected from polytetrafluoroethylene (also known as Teflon) as an example, and can withstand a process temperature of not less than 150°C, and it has anti-sticking properties. , In order to reduce the adhesion between the wafer 101 and the adsorption of impurities on the top surface 21 of the carrier plate 2.

In some embodiments, the cladding layer 5 may not be provided as required, as long as the joint between the top surface 21 of the carrier plate 2 and the grooves 3 is a lead angle, so as to avoid the right angle of the grooves 3 It is fine if the back is scratched.

During implementation, a to-be-separated object formed by bonding the temporary substrate 102 and the wafer 101 with wax as shown in FIG. 1 can be placed in the direction in which the wafer 101 faces the carrier plate 2 On the top surface 21 of the carrier plate 2 shown in 2, since the grooves 3 are at least partially connected to each other, the joint surface of the wafer 101 corresponding to the grooves 3 and the corresponding grooves 3 form an interior Space; then, through the suction holes 4 suction, so that the internal space compared to the external environment to form a negative pressure state, so that the wafer 101 uses the pressure difference between the external environment and the internal space to be fixed in the Carrier plate 2; subsequently, adjust the process temperature to about 160 ℃, so that the wax used to bond the wafer 101 and the temporary substrate 102 is softened into a molten state, so that the temporary substrate 102 and the wafer 101 The force drops; then, by applying a lateral thrust to the temporary substrate 102 (that is, the direction of force is parallel to the top surface 21 of the carrier plate 2), the temporary substrate 102 is pushed out by translation, and the wafer 101 It is separated from the temporary substrate 102. In this case, since the joints between the grooves 3 and the top surface 21 of the carrier plate 2 are non-right-angled chamfers, it is not easy to produce joints when the wafer 101 is fixed on the carrier plate 2 Scratches, therefore, during the process of moving the temporary substrate 102, it is possible to reduce the occurrence of scratches on the backside of the wafer 101 by the edges of the trenches 3. In addition, by covering the cladding layer 5 on the top surface 21 of the carrier plate 2, the contact surface with the wafer 101 can have a smooth surface and anti-adhesion properties, thereby further reducing the damage caused to the wafer 101. Damage, while reducing the adhesion of foreign objects.

In summary, the wafer separation device 200 of the present application uses the sidewall 31 of each groove 3 formed on the carrier plate 2 and the top surface 21 to form a chamfered angle, so as to prevent the peripheries of the grooves 3 from facing each other. The wafer 101 in contact with it scratches the back of the wafer 101 due to the sharp right-angle angle. In addition, the coating layer 5 can make the contact surface with the wafer 101 anti-adhesive properties. It can avoid sticking to the wafer 101 or adsorbing impurities on the top surface 21 of the carrier plate 2, so it can indeed achieve the purpose of new cost.

However, the above are only examples of the present model. When the scope of implementation of the present model cannot be limited by this, all simple equivalent changes and modifications made in accordance with the patent scope of the present model application and the contents of the patent specification still belong to This new patent covers the scope.

101: Wafer 102: Temporary substrate 200: Wafer separation device 2: Carrier plate 21: top surface 3: groove 31: side wall 32: bottom wall 4: Suction hole 5: Coating layer

The other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, among which: Figure 1 is a schematic cross-sectional view illustrating a conventional wafer separation device; Figure 2 is a three-dimensional schematic diagram illustrating an embodiment of the novel wafer separation device; and 3 is a schematic cross-sectional view illustrating the cross-sectional structure along the line III-III of FIG. 2.

101: Wafer

102: Temporary substrate

2: Carrier plate

21: top surface

3: groove

31: side wall

32: bottom wall

5: Coating layer

Claims (7)

A wafer separation device suitable for separating a wafer bonded on a temporary substrate from the temporary substrate, comprising: A carrier tray with a top surface for placing the temporary substrate and the wafer to be separated; Multiple grooves, each groove is formed by two side walls extending downward from the top surface of the carrier plate, and a bottom wall connecting the two side walls away from the top surface, and each groove The junction between the side wall and the top surface forms a lead angle; and A plurality of suction holes are distributed on the bottom walls of the grooves, and can be used to pump air to the corresponding grooves. The wafer separation device according to claim 1, further comprising a coating layer covering the top surface of the carrier plate, the coating layer extending to cover the chamfers at the junction of the grooves and the top surface, And selected from high temperature resistant polymer materials. The wafer separation device according to claim 2, wherein the cladding layer extends from the top surface into the trenches, and covers the sidewalls of the trenches. The wafer separation device according to claim 2 or 3, wherein the coating layer is selected from polytetrafluoroethylene. The wafer separation device according to claim 1, wherein the grooves are interlaced with each other, and at least part of the grooves are connected to each other. The wafer separation device according to claim 1, wherein the grooves may be striped, ring-shaped or arc-shaped, and each may be the same or different. The wafer separation device according to claim 1, wherein the grooves are distributed in a radial and/or concentric ring shape.

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