JP6116155B2 - Wafer processing method - Google Patents

Description

The present invention relates to a method of processing U Eha.

  In recent years, as a new three-dimensional mounting technology, a plurality of semiconductor chips are stacked, a through electrode (via electrode) penetrating the stacked semiconductor chips is formed, and a semiconductor chip is connected to each other, or a plurality of semiconductor wafers are stacked. A lamination technique (TSV: Through Silicon Via) for connecting semiconductor wafers by forming through electrodes penetrating the laminated semiconductor wafers is being developed (for example, see Patent Documents 1 and 2).

JP 2004-207606 A JP 2005-136187 A

  However, in the TSV process, there is a problem that when the wafer is bonded to the substrate with the resin, the resin protrudes from the outer periphery of the wafer, and the resin protruding in the etching process is scattered during the etching and adheres to the wafer surface.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a wafer processing method for removing the protruding resin in order to suppress scattering of the resin in the etching process.

In order to solve the above-mentioned problems and achieve the object, a wafer processing method according to the present invention is characterized in that a plurality of devices are partitioned on a surface of a semiconductor substrate by lines to be divided, and the semiconductor substrate is separated from the device electrodes. A wafer processing method comprising a device region having a Via electrode embedded toward the back surface of the wafer and a chamfered portion in an outer peripheral surplus region surrounding the device region, wherein the chamfered portion of the wafer is removed from the front surface side. A chamfering process is performed to remove about half of the thickness, a carrier plate is disposed on the surface of the wafer subjected to the chamfering process via a resin, and grinding is performed on the wafer from the back surface. and thinning the wafer to remove the chamfer, holding the wafer on the upper surface of the provided the rotation can spinner table to the cleaning chamber of the cleaning device for cleaning the wafer , By rotating the spinner table, the solvent for melting the resin toward the resin protruding from the outer edge of the wafer disposed on the carrier plate through the resin held on the upper surface of the spinner table soluble agent injected from the injection nozzle, characterized in that you inject wash solution from wash solution injection nozzle to the upper surface of the wafer held on the spinner table.

According to the wafer processing method of the present invention, the resin protruding from at least the chamfered portion of the resin adhered to the wafer after grinding in the cleaning apparatus is melted. For this reason, since the resin sticking out from at least the chamfered portion of the resin stuck to the wafer before etching can be removed, it is possible to suppress the resin stuck to the wafer during the scattering.

  Also, since the resin protruding from at least the chamfered portion of the resin adhered to the wafer in the cleaning device is removed, it is not necessary to provide a separate dedicated resin removing device for removing the protruding resin, and the cost is reduced. Soaring can be suppressed. Furthermore, when the wafer is washed, the resin sticking out of the wafer is removed from at least the chamfered portion, so there is no need to perform a dedicated process to remove the protruding resin. There is no decline in performance.

FIG. 1 is a diagram illustrating a wafer to be cleaned by the wafer cleaning apparatus according to the embodiment. FIG. 2 is a cross-sectional view showing a state in which a carrier plate is attached to the wafer shown in FIG. FIG. 3 is a cross-sectional view showing a state in which grinding is performed on the wafer to which the carrier plate shown in FIG. 1 is attached. FIG. 4 is a cross-sectional view illustrating a configuration example of the wafer cleaning apparatus according to the embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the structures described below can be combined as appropriate. Various omissions, substitutions, or changes in the configuration can be made without departing from the scope of the present invention.

  A wafer cleaning apparatus (hereinafter simply referred to as a cleaning apparatus) according to this embodiment will be described with reference to FIGS. 1A is a perspective view showing a wafer to be cleaned by the wafer cleaning apparatus according to the embodiment, and FIG. 1B is a cross-sectional view taken along line IB-IB in FIG. 1A. 2 is a cross-sectional view showing a state in which the carrier plate is attached to the wafer shown in FIG. 1A, and FIG. 3 is a wafer in which the carrier plate shown in FIG. 1A is attached. FIG. 4 is a cross-sectional view showing a configuration example of the wafer cleaning apparatus according to the embodiment.

  The cleaning apparatus 1 according to the present embodiment shown in FIG. 4 cleans the back surface WR of the wafer W on which the carrier plate P is disposed on the front surface WS via the resin J.

  Note that a wafer W (corresponding to a semiconductor substrate) whose back surface WR is cleaned by the cleaning apparatus 1 according to the present embodiment is a disk-shaped semiconductor wafer whose base material is silicon, sapphire, gallium, or the like in this embodiment. It is an optical device wafer. In the wafer W, as shown in FIG. 1A, a plurality of devices D are partitioned on the surface WS by a division line S. Further, as shown in FIG. 1B, the wafer W includes a device region DR having a via electrode E embedded from the electrode of the device D toward the back surface WR (corresponding to the upper surface), and FIG. As shown, a chamfered portion C is provided in the outer peripheral surplus region GR surrounding the device region DR. The Via electrode E is made of a metal such as copper, and an end surface is exposed on the surface WS side of the wafer W, and is embedded from the surface WS toward the back surface WR up to the center in the thickness direction of the wafer W.

  Further, the wafer W is subjected to a chamfering process in which the chamfered portion C is removed from the surface WS side by about half of the thickness of the chamfered portion C before being cleaned by the cleaning apparatus 1 as shown in FIG. In addition, the carrier plate P is disposed through the resin J having adhesiveness on the surface WS. Then, as shown in FIG. 3, the wafer W is ground from the back surface WR using a grinding wheel G or the like, and about half of the thickness is removed so that the end surface on the back surface WR side of the Via electrode E is not exposed. And the chamfered portion C is removed. In addition, as a material which comprises resin J, the epoxy resin and acrylic resin which harden | cure when heated, for example, the UV curing type hardened | cured when an ultraviolet-ray is irradiated are used. Further, when the carrier plate P is disposed on the surface WS of the wafer W via the resin J, as shown in FIG. 3, a part of the resin J (the protruding resin is replaced with another resin). And a chamfered portion C (hereinafter also referred to as an outer edge of the wafer W after the chamfered portion C is removed). That is, in the present invention, protruding from the chamfered portion C means protruding from the chamfered portion C and protruding from the outer edge of the wafer W after the chamfered portion C is removed.

  As shown in FIG. 4, the cleaning apparatus 1 includes a cleaning chamber 2, a spinner table 3, a cleaning liquid injection nozzle 4, a solvent injection nozzle 5, and control means (not shown). The cleaning chamber 2 is for performing cleaning of the wafer W while being isolated from the outside. In the present embodiment, the cleaning chamber 2 has a cylindrical shape with an upper opening, and a spinner table 3, a cleaning liquid injection nozzle 4, and a solvent injection nozzle 5 are disposed therein. In the cleaning chamber 2, the wafer W is taken in and out through an upper opening by a conveying means (not shown).

  The spinner table 3 is provided in the cleaning chamber 2 and can rotate by sucking and holding the wafer W on the upper surface 3a. The spinner table 3 has a disk shape in which a portion constituting the upper surface 3a is made of porous ceramic or the like, and is connected to suction means (not shown). In the spinner table 3, the wafer W is placed on the upper surface 3a via the carrier plate P, and the wafer W is sucked and held by applying a negative pressure by the suction means. The spinner table 3 is connected to a drive shaft 6a of an electric motor 6 attached to an apparatus main body (not shown) of the cleaning apparatus 1. The spinner table 3 is rotated around an axis parallel to the vertical direction by the rotational driving force of the electric motor 6.

  The cleaning liquid injection nozzle 4 performs cleaning while spraying a cleaning liquid supplied from a chemical liquid supply means (not shown) to the back surface WR as the upper surface of the wafer W held on the spinner table 3. The cleaning liquid injection nozzle 4 is moved by a motor (not shown) over a position where the tip is opposed to the upper side of the wafer W held on the spinner table 3 and a position where the wafer W is held on the spinner table 3. It is provided so as to be able to swing. In the present invention, pure water, acidic and alkaline solutions can be used as the cleaning liquid. In the present invention, a plurality of cleaning liquid injection nozzles 4 may be provided and a plurality of cleaning liquids may be used.

  The solvent injection nozzle 5 injects the solvent Y toward the resin JA protruding from at least the chamfered portion C of the wafer W disposed on the carrier plate P through the resin J held on the upper surface 3a of the spinner table 3. It is. In the solvent injection nozzle 5, an injection port for injecting the solvent Y is disposed on the side of the resin J attached to the surface WS of the wafer W held by the spinner table 3. The solvent Y ejected by the solvent ejection nozzle 5 is a solvent for melting the resin J, and for example, a solvent such as tetrahydrofuran or dimethylformamide is used.

  Further, the cleaning apparatus 1 includes a moving means (not shown) that moves the cleaning chamber 2 and the spinner table 3 relatively in the vertical direction, and an air injection nozzle (not shown) that blows pressurized air onto the spinner table 3. Yes.

  The control means controls the above-described constituent elements that constitute the cleaning apparatus 1. The control means causes the cleaning apparatus 1 to perform a cleaning operation on the wafer W on which the carrier plate P is disposed and ground. Note that the control means is mainly composed of an arithmetic processing unit constituted by a CPU or the like, or a microprocessor (not shown) provided with a ROM, a RAM, or the like.

  Next, the cleaning operation of the cleaning apparatus 1 according to this embodiment will be described. With the spinner table 3 positioned above the cleaning chamber 2 by the moving means, the surface WS of the wafer W on which the carrier plate P is disposed and ground by the conveying means (not shown) is passed through the resin J. The arranged carrier plate P is placed on the upper surface 3 a of the spinner table 3. In this state, the tip of the cleaning liquid ejection nozzle 4 is retracted from above the spinner table 3. Then, the control means drives the suction means to suck and hold the wafer W on the upper surface 3a of the spinner table 3, and drives the moving means to lower the spinner table 3 relative to the cleaning chamber 2. Let

  After that, as shown in FIG. 4, the control means drives the electric motor 6 to rotate the spinner table 3 and the wafer W around the axis, and removes the solvent Y from the injection port of the solvent injection nozzle 5. And sprayed for a certain period of time toward the outer peripheral surface of the resin JA adhered to the surface WS of the wafer W held on the surface. Then, the resins JA and J are gradually melted from the outer peripheral surface side, and the melted resins JA and J are discharged out of the cleaning apparatus 1 through a discharge port (not shown) provided on the bottom surface of the cleaning chamber 2.

  In addition, by injecting the solvent Y from the injection port of the solvent injection nozzle 5 for a certain time, at least a part of the resin JA that protrudes from the chamfered portion C of the resin J is melted. In the present invention, if the solvent spray nozzle 5 sprays the solvent Y toward the outer peripheral surface of the resin JA and the resin JA protruding from the chamfered portion C of the resin J can be melted, the wafer W and the carrier plate The outer peripheral portion of the resin J sandwiched between the wafer W and the carrier plate P may be melted without protruding from the chamfered portion C of the resin J within a range in which P does not shift. In short, in the present invention, at least the resin JA protruding from the chamfered portion C may be melted with the solvent Y.

  After injecting the solvent Y from the injection port of the solvent injection nozzle 5 for a certain period of time, the control means stops the injection of the solvent Y from the injection port of the solvent injection nozzle 5, and then swings the cleaning liquid injection nozzle 4. The tip of the cleaning liquid spray nozzle 4 is made to face the back surface WR of the wafer W. Then, the control means causes the chemical liquid supply means to supply the cleaning liquid to the cleaning liquid injection nozzle 4 and injects the cleaning liquid toward the wafer W held on the spinner table 3. Then, due to the centrifugal force generated by the rotation of the spinner table 3, the cleaning liquid sprayed toward the wafer W flows on the wafer W in the outer peripheral direction, and flows down from the wafer W together with contamination attached to the back surface WR and the like of the wafer W. Then, the cleaning liquid used for cleaning the wafer W is discharged out of the cleaning apparatus 1 through a discharge port provided on the bottom surface of the cleaning chamber 2.

  After the cleaning liquid is jetted for a predetermined time, the control means swings the cleaning liquid jet nozzle 4 and retreats from above the wafer W. After that, the control means blows air pressurized from an air injection nozzle (not shown) onto the wafer W to dry the wafer W sucked and held on the spinner table 3, and then stops the rotation of the spinner table 3. Then, the control unit drives the moving unit to raise the spinner table 3 relative to the cleaning chamber 2, and then stops the suction unit to release the suction / holding of the spinner table 3. Thereafter, the control means takes the wafer W out of the cleaning chamber 2 by the conveying means and conveys the wafer W to the next process. In the next step, the wafer W is subjected to etching such as plasma etching on the back surface WR side, the Via electrode E is exposed, and then the back surface WR side is covered with an insulating film, and the end surface of the Via electrode E on the back surface WR side After the bump is attached to the device D, the device D is divided for each device D by cutting or laser processing.

  As described above, the cleaning apparatus 1 according to the present embodiment melts the resin JA that protrudes from at least the chamfered portion C out of the resin J that is adhered to the wafer W before being etched after being ground in the cleaning chamber 2. . For this reason, since the resin JA protruding from at least the chamfered portion C of the resin J adhered to the wafer W before etching can be removed, the scattering of the resin J adhered to the wafer W during etching is suppressed. it can.

  In addition, since the resin J protruding from at least the chamfered portion C of the resin J adhered to the wafer W in the cleaning chamber 2 is removed, a dedicated resin removing device is separately provided to remove the protruding resin J. There is no need to suppress the rise in cost. Further, when the wafer W is washed, the resin J protruding from at least the chamfered portion C of the resin J adhered to the wafer W is removed, and therefore, a separate dedicated process is required to remove the protruding resin JA. There is no need to do so, and productivity does not decrease.

  The cleaning device 1 according to the present embodiment is configured as a device for cleaning the wafer W alone. However, in the present invention, the cleaning device 1 is provided integrally with a device that performs various processes such as grinding. May be configured.

  The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Wafer cleaning apparatus 3 Spinner table 3a Upper surface 4 Cleaning liquid injection nozzle 5 Solvent injection nozzle W Wafer (semiconductor substrate)
WS front WR back (top)
J, JA Resin Y Solvent P Carrier plate D Device S Divided line E Via electrode DR Device area GR Peripheral surplus area C Chamfer

Claims (1)

A plurality of devices are partitioned by dividing lines on the surface of the semiconductor substrate, a device region having a Via electrode embedded from the device electrode toward the back surface of the semiconductor substrate, and a chamfered portion in an outer peripheral surplus region surrounding the device region A method of processing a wafer comprising :
Chamfering to remove the chamfered portion of the wafer from the surface side by about half the thickness,
A carrier plate is disposed on the surface of the chamfered wafer via a resin;
Grinding the wafer from the back surface, thinning the wafer and removing the chamfered portion,
The wafer was held on the upper surface of the provided the rotation can spinner table to the cleaning chamber of the cleaning device for cleaning the wafer,
By rotating the spinner table, Solvent The solvent to melt the resin toward the resin protruding from the outer edge of the wafer disposed on the carrier plate through the resin held on the upper surface of the spinner table Spray from the spray nozzle ,
Roux Eha processing methods to inject wash solution from wash solution injection nozzle to the upper surface of the wafer held on the spinner table.

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