Wafer Inspection Equipment

Abstract

To provide a wafer inspection device which surely holds a wafer without generating a local deformation (elongation or the like) in a film material that is easily deformed when inspecting the wafer attached to the film material.SOLUTION: A wafer inspection device 1 for inspecting a wafer W supported by an adhesive film M attached to a ring-shaped frame R comprises: a holding part 2 which is in contact with the adhesive film M and holds the wafer W in a prescribed posture; an illumination part 3 which emits illumination light L1 toward the wafer W; an imaging part 4 which images the appearance and / or inside of the wafer W; and an inspection part 5 which performs an inspection on the basis of an inspection image G obtained by imaging the appearance and / or inside of the wafer W imaged by the imaging part 4. In the holding part 2, a porous member 22 is a portion which is in contact with the adhesive film M and is arranged so as to surround the wafer W in a region set on the outer side than the outer edge of the wafer W.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus for inspecting a wafer supported by an adhesive film attached to a ring-shaped frame. [Background technology]

[0002] Chip components such as semiconductor devices are manufactured by stacking circuit patterns on a silicon wafer at a predetermined repeat pitch, then dicing the wafer to a predetermined size and packaging it. Various inspections are carried out during the manufacturing process to check whether the stacked circuit patterns are formed in the desired state (for example, see Patent Document 1).

[0003] Furthermore, semiconductor devices are sometimes inspected using a transmitted illumination method, taking advantage of the infrared transmittance property of silicon wafers (for example, Patent Document 2).

[0004] Typically, the wafer to be diced is placed with the circuit-formed surface facing up, and its underside is supported by an adhesive film attached to a ring-shaped frame. Then, while the ring-shaped frame is held in a predetermined position, the wafer is lifted from below by a push-up member (i.e., expanded) to be diced into individual pieces (e.g., Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-258067 [Patent Document 2] Japanese Patent Application Publication No. 8-220008 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-273895 Summary of the Invention [Problem to be solved by the invention]

[0006] For example, when inspecting the outer periphery of the wafer using a transmitted illumination method, or when performing processing that requires precise position control from the adhesive film side, in order to hold the wafer supported by the adhesive film in a predetermined position, it is necessary to hold the wafer just outside the radial direction of the outer edge of the wafer (i.e., the adhesive film).This is because the influence of deformation of the link-shaped frame and adhesive film is reduced.

[0007] However, adhesive films are flexible and easily deformed because they are used to stretch diced wafers into chips. In other words, if holes or grooves are provided on the surface of the support member and strong negative pressure suction is applied, the adhesive film may undergo localized deformation (e.g., stretching) and may not return to its original shape. On the other hand, if the negative pressure suction force is weakened, the wafer may shift position or lose adhesion when it is moved while being held.

[0008] Therefore, an object of the present invention is to provide a wafer inspection device that can reliably hold a wafer attached to a film material without causing local deformation (elongation, etc.) in the easily deformable film material when inspecting the wafer. [Means for solving the problem]

[0009] In order to solve the above problems, one aspect of the present invention is to provide: A wafer inspection device that inspects a wafer supported by an adhesive film attached to a ring-shaped frame, a holding portion that contacts the adhesive film and holds the wafer in a predetermined position; an illumination unit that irradiates illumination light toward the wafer; an imaging unit that captures an image of the exterior and / or interior of the wafer; an inspection unit that performs inspection based on an inspection image of the appearance and / or interior of the wafer captured by the imaging unit, The holding part is The portion that contacts the adhesive film is a porous member, The porous member is disposed so as to surround the wafer in a region set outside the outer edge of the wafer.

[0010] According to the above embodiment, the lower surface of the adhesive film can be suction-held over a relatively wide area outside the outer edge of the wafer at a negative pressure slightly lower than the atmospheric pressure. [Effects of the Invention]

[0011] When inspecting a wafer attached to a film material, even a film material that is easily deformed can be reliably held without causing local deformation (elongation, etc.). [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing an example of a wafer inspection apparatus in an embodiment embodying the present invention. [Figure 2] FIG. 10 is a schematic diagram showing another example of a wafer inspection apparatus in an embodiment embodying the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the three axes of a Cartesian coordinate system are designated as X, Y, and Z, the horizontal direction is designated as the X direction and the Y direction, and the direction perpendicular to the XY plane (i.e., the direction of gravity) is designated as the Z direction. In addition, the direction against gravity in the Z direction is designated as up, and the direction in which gravity acts is designated as down. In addition, the direction of rotation around the Z direction as the central axis is designated as the θ direction.

[0014] The wafer inspection device 1 inspects a wafer W supported by an adhesive film M attached to a ring-shaped frame F.

[0015] Figure 1 is a schematic diagram showing an example of a wafer inspection apparatus in an embodiment embodying the present invention. Figure 1(a) shows a perspective view and a block diagram of the positional relationship between each component of the wafer inspection apparatus 1 and the wafer W it holds. Figure 1(b) shows a cross-sectional view of the positional relationship between each component of the wafer inspection apparatus 1 and the wafer W it holds.

[0016] Specifically, the wafer inspection device 1 receives a ring-shaped frame F in a horizontal position, which is carried by a handler (not shown) or the like, and inspects the wafer W while holding it in a predetermined position. Examples of wafers W to be inspected include those that will become chip components of semiconductor devices (for example, having circuit patterns formed on the upper surface) and those that will become MEMS components (having structures formed inside). More specifically, the wafer inspection device 1 includes a holding unit 2, an illumination unit 3, an imaging unit 4, and an inspection unit 5. The wafer inspection device 1 further includes a moving unit M, a computer CP, a controller CN, and the like.

[0017] The holding part 2 holds the wafer W in a predetermined position by contacting the adhesive film M. Specifically, the holding part 2 supports and holds the adhesive film M from the underside so that the wafer W maintains a horizontal position and does not shift in position in the horizontal or vertical directions. More specifically, the holding portion 2 has a ring shape with a predetermined width, like a hollowed-out disk, and includes a main body portion 20, a frame support portion 21, a film contact portion 22, a communication portion 23, etc.

[0018] The frame support portion 21 supports the lower portion of the ring-shaped frame F from the underside. Specifically, the frame support portion 21 supports the ring-shaped frame F from the underside so that the ring-shaped frame F maintains a horizontal position and does not shift in position in the vertical direction. More specifically, the frame support portion 21 is made of a hard material such as a ring-shaped metal or resin with a flat upper surface, and is configured to support the ring-shaped frame F by abutting against the underside of the ring-shaped frame F and / or the underside of an adhesive film M attached to the underside of the ring-shaped frame F.

[0019] The film contact portion 22 comes into contact with the adhesive film M. Specifically, the film contact portion 22 contacts the underside of the adhesive film M to support and hold the wafer W supported by the adhesive film M in a predetermined posture, and the inner edge 22n of the film contact portion 22 is positioned so as to surround the wafer W in an area E set radially outward from the outer edge We of the wafer W. More specifically, the film contact portion 22 is made of a porous material. The porous member is made by collecting and solidifying small particles of metal or resin, and has an internal structure in which the upper, lower and side surfaces are air permeable to each other. Specifically, the surface of the film contact portion 22 is uneven, but the upper end is formed or processed to be flat when viewed as a whole.

[0020] The communication section 23 connects the lower surface or interior of the film contact section 22 with negative pressure generating means V arranged inside or outside the apparatus. Specifically, the communication section 23 is configured by a groove, a hole, or the like provided in the main body 20 of the holding section 2, and is connected to the negative pressure generating means V via a switching valve 24 or the like.

[0021] The negative pressure generating means V creates a pressure inside the film contact portion 22 that is lower than atmospheric pressure. Specifically, the negative pressure generating means V can be exemplified by a vacuum pump, an ejector, or the like.

[0022] The positional relationship between the wafer W supported by the adhesive film M attached to the ring-shaped frame R and each part of the holder 2 can be exemplified as follows. From the inside out, they are the outer edge We of the wafer W, the inner edge 22n of the film contact portion 22, the inner edge Rn of the ring-shaped frame R, the outer edge 22e of the film contact portion 22, the outer edge Me of the adhesive film M, the outer edge Rn of the ring-shaped frame R, and the outer edge of the frame support portion 21.

[0023] Because the holding part 2 has such a configuration, the adhesive film M to which the wafer W is attached is brought into contact with the film contact part 22, and a negative pressure is applied to the film contact part 22, thereby generating a suction force in the space formed by the adhesive film M and the porous member. As a result, the adhesive film M is sucked and held by suction by the film contact part 22, and the wafer W is held in a predetermined posture.

[0024] The illumination unit 3 irradiates the wafer W with illumination light L1. Specifically, a predetermined amount of illumination light L1 is irradiated toward the imaging field of view F so that the observation light L2 required for imaging by the imaging unit 4 can be obtained. More specifically, examples of the illumination unit 3 include an LED light, a metal halide lamp, a xenon lamp, and a laser diode, which are arranged inside and below the film contact portion 22 of the holding unit 2. The illumination unit 3 switches on and off and emits a strobe light at a predetermined location or timing based on signal control from an external device (in this embodiment, the controller CN).

[0025] The imaging unit 4 captures an image of the exterior and / or interior of the wafer W. Specifically, the imaging unit 4 outputs to an external device (a computer CP in this embodiment) a video signal or video data of an inspection image G obtained by capturing an image of the exterior and / or interior of the wafer W. The illumination unit 3 and imaging unit 4 are disposed opposite to each other so that illumination light L1 transmitted through the wafer W is incident on the imaging unit 4. More specifically, the imaging unit 4 includes an imaging camera having an imaging element of a predetermined area (so-called image area sensor), a lens that allows illumination light L2 that has passed through the wafer W to be incident and forms an image of the top surface or interior of the wafer W on the imaging element, and the like.

[0026] The inspection unit 5 performs inspection based on the inspection image G obtained by capturing the external appearance and / or the internal portion of the wafer W captured by the imaging unit 4. Specifically, the inspection unit 5 performs image processing etc. on the inspection image G, performs differential processing on a comparison image that serves as an inspection standard to detect defects, foreign matter, etc., or detects defects, foreign matter, etc. based on pixel brightness information, etc. Then, information on the position and size of the detected defects, foreign matter, etc. is output to a display, a host computer, etc. More specifically, the inspection unit 5 is composed of a processing unit, an image processing unit, etc. of the computer CP, an execution program, etc.

[0027] The moving unit M moves the holding unit 2 and the imaging unit 4 relative to each other. Specifically, the moving unit M moves the holding unit 2 holding the wafer W relative to the imaging area F of the imaging unit 4 so that the imaging unit 4 can capture a thorough image of the inspection area set on the surface and / or inside of the wafer W. More specifically, the moving unit M is equipped with a combination of an XY stage mechanism that moves the main body 20 of the holding unit 2 in the XY direction at a predetermined speed and stops it at a predetermined position, and a rotation mechanism that rotates the holding unit 2 in the θ direction and stops it at a predetermined angle (a so-called XYθ stage mechanism), and is attached to the device frame 1f.

[0028] The computer CP receives signals and data from the outside, performs predetermined arithmetic processing and image processing, and outputs signals and data to the outside. Specifically, the computer CP performs the following functions: -Setting and registering the size of the field of view F, imaging position, order, etc. · Setting and registering inspection conditions, etc. ·Input inspection image G ·Process the image and perform inspection based on the inspection conditions More specifically, the computer CP is composed of an input section and an output section, a storage section (called a register or memory), a control section and a calculation section (called a CPU or MPU), an image processing unit (called a GPU), an auxiliary storage device (such as a HDD or SSD), etc. (i.e., hardware), and their execution programs, etc. (i.e., software).

[0029] The controller CN inputs and outputs signals and data to and from external devices (in this embodiment, devices such as the holding unit 2, lighting unit 3, and imaging unit 4, and a computer CP, etc.), and performs predetermined control processing. Specifically, the controller CN executes the following functions. A drive signal is output to the switching valve 24 of the holding unit 2 to hold / release the wafer W. -Outputs signals such as ON / OFF of illumination light L1 to lighting unit 3 - Outputs an imaging trigger to the imaging camera of the imaging unit 4 Drive control of moving part M: A function that monitors the current position and angle of the XYθ stage mechanism, outputs a drive signal, and controls the position and angle. More specifically, the controller CN is composed of a part of the computer CP, a dedicated programmable logic controller, etc. (i.e., hardware), and its execution program, etc. (i.e., software).

[0030] Because the wafer inspection device 1 according to the present invention has this configuration, it can create a negative pressure in a relatively wide area outside the outer edge We of the wafer W and suck in the underside of the adhesive film M. At this time, the underside of the adhesive film M can be sucked in and securely held even at a negative pressure slightly lower than the atmospheric pressure. Therefore, when inspecting a wafer attached to a film material, even a film material that is prone to deformation can be securely held without causing local deformation (elongation, etc.).

[0031] (Variation) In the above description, an example has been shown in which the outer edge 22e of the film contacting portion 22 (i.e., the boundary with the frame supporting portion 21) is located outside the inner edge Rn of the ring-shaped frame R and inside the outer edge Me of the adhesive film M, as a positional relationship between the wafer W supported by the adhesive film M attached to the ring-shaped frame R and each portion of the holding portion 2. This configuration is preferable because a relatively wide area of ​​the underside of the adhesive film M can be supported and held by suction by the film contacting portion 22. However, in realizing the present invention, the components of the holding portion 2 are not limited to this arrangement, and the outer edge 22e of the film abutting portion 22 may be arranged more inward than the inner edge Rn of the ring-shaped frame R. This is preferable because the ring-shaped frame R is not present above the film abutting portion 22 and only the adhesive film M can be supported from the underside, which increases adhesion to the adhesive film M even if the ring-shaped frame R is deformed, such as warped or sagged.

[0032] Figure 2 is a schematic diagram showing another example of a wafer inspection apparatus in an embodiment embodying the present invention. Figure 2(a) shows a perspective view and a block diagram of the positional relationship between each component of the wafer inspection apparatus 1 and the wafer W it holds. Figure 2(b) shows a cross-sectional view of the positional relationship between each component of the wafer inspection apparatus 1 and the wafer W it holds.

[0033] Furthermore, in the above description, the holding portion 2 is configured such that the upper end surface of the frame support portion 21 and the contact surface (ie, upper end surface) of the film contact portion 22 are at the same height (ie, there is no step). However, in realizing the present invention, the holding portion 2 is not limited to this configuration, and the contact surface (i.e., the upper end surface) of the film contact portion 22 may be positioned higher than the upper end surface of the frame support portion 21 (the film contact portion 22 may protrude). In other words, if the film contact portion 22 protrudes from the upper end surface of the frame support portion 21, the gap between the lower surface of the adhesive film M and the film contact portion 22 is reduced, and adhesion is improved when negative pressure suction is applied, which is preferable.

[0034] Furthermore, the protrusion amount of the film contact portion 22 may be set to be larger than the amount of deformation due to warping, undulation, etc. of the ring-shaped frame R. In this way, when the ring-shaped frame R is placed on the holding portion 2, the underside of the adhesive film M abuts against the film contact portion 22 around the entire periphery without any gaps, which is preferable as it further improves adhesion when suctioned under negative pressure.

[0035] (Regarding auxiliary support part 6) In the above description, an example has been given of a configuration in which the inner edge 22n of the film abutment portion 22 of the holding portion 2 is positioned outside the outer edge We of the wafer W supported by the adhesive film M attached to the ring-shaped frame R (i.e., the area immediately below the wafer W is hollow). However, in realizing the present invention, the holding portion 2 is not limited to this configuration, and may be configured to include an auxiliary support portion 6.

[0036] The auxiliary support portion 6 supports a predetermined portion of the wafer W radially inward of the outer edge We. Specifically, the auxiliary support portion 6 supports the adhesive film M from the underside of the wafer W so that the wafer W, which is prone to bending, can be held in a predetermined posture. More specifically, the auxiliary support 6 is made of a material that transmits the illumination light L1 and that can provide a sufficient amount of observation light L2 (i.e., a substantially transparent material). For example, if the illumination light L1 is visible light, the auxiliary support 6 is made of a material that transmits visible light, such as a glass plate, acrylic resin, or polycarbonate resin. Furthermore, if the wafer W is made of silicon crystal and the illumination light L1 is near-infrared light, the auxiliary support 6 may be made of silicon crystal.

[0037] The holding section 2 may be configured so that the upper end surface of the auxiliary support section 6 is at the same height as the upper end surface of the film contact section 22 (i.e., there is no step), or may be configured so that they are positioned at different heights.

[0038] (Regarding height adjustment part 7) Furthermore, the holding portion 2 may include a height adjustment portion 7 .

[0039] The height adjustment unit 7 changes the height of the contact surface (i.e., the upper end surface) of the auxiliary support unit 6 that contacts the adhesive film M relative to the height of the contact surface (i.e., the upper end surface) of the film contact unit 22. Specifically, examples of the height adjustment unit 7 include an electric actuator, a hand screw, a spacer, and the like. The height adjustment unit 7 may set the height difference (ie, step) depending on the degree of deformation of the wafer W and ring-shaped frame R to be handled, the thickness and flexibility of the adhesive film M, and the like.

[0040] In the above description, the height adjustment unit 7 changes the height of the contact surface (that is, the upper end surface) of the auxiliary support unit 6. However, the height adjustment section 7 may be configured to change the height of the contact surface (that is, the upper end surface) of the film contact section 22 relative to the upper end surface of the frame support section 21.

[0041] (About lighting unit 3) In the above description, the configuration in which the illumination unit 3 and the imaging unit 4 are arranged above and below facing each other across the wafer W (so-called transmitted illumination system) has been exemplified. However, the illumination unit 3 and the imaging unit 4 are not limited to this configuration, and may both be arranged above the wafer W (so-called reflective illumination type).

[0042] (Regarding holding part 2) In the above description, an example has been shown in which the upper surface of the frame support portion 21 is made of a flat, ring-shaped hard material such as metal or resin. This configuration is preferable because it makes it easy to maintain the ring-shaped frame F in a horizontal position while preventing it from shifting in the vertical direction. However, the upper surface of the frame support portion 21 is not limited to this configuration, and may be made of a resilient material such as sponge, rubber, or soft resin.

[0043] In the above description, an example has been shown in which the porous member is arranged in a ring shape (i.e., continuously) of a predetermined width in the film contact portion 22. With this configuration, the film contact portion 22 has a relatively large area and sucks and holds the adhesive film M with a low negative pressure, which is preferable because it does not cause deformation of the adhesive film M. However, the film contact portion 22 is not limited to this configuration, and may be arranged in an elliptical or polygonal shape, or may be arranged intermittently (for example, in an arc shape or scattered) as long as deformation of the adhesive film M does not occur.

[0044] In the above description, the holding portion 2 is illustrated as having a configuration in which the outer edge of the frame support portion 21 is set at the same position as the outer edge Rn of the ring-shaped frame R. However, the holding portion 2 is not limited to this configuration, and the outer edge of the frame support portion 21 may be positioned outside or inside the outer edge Rn of the ring-shaped frame R. [Explanation of symbols]

[0045] 1. Wafer inspection equipment 2 Holding part 3. Lighting section 4. Imaging unit 5. Inspection Department 6 Auxiliary support part 7 Height adjustment section 20 Main body 21 Frame support 22 Film contact part (porous member) 22e outer edge 22n Inner edge 23 Communication section 24 Switching valve W wafer We Outer Edge M adhesive film Me Outer Edge R ring frame Re outer edge Rn inner edge G Inspection image L1 illumination light L2 Illumination light transmitted through the wafer E area V Negative pressure generating means

Claims

1. A wafer inspection device that inspects a wafer supported by an adhesive film attached to a ring-shaped frame, a holding part that contacts the adhesive film and holds the wafer in a predetermined position; an illumination unit that irradiates illumination light toward the wafer; an imaging unit that images the exterior and / or interior of the wafer; an inspection unit that performs inspection based on an inspection image of the appearance and / or the inside of the wafer captured by the imaging unit, The holding portion is The portion that contacts the adhesive film is a porous member, The porous member is disposed so as to surround the wafer in a region set outside the outer edge of the wafer, the holding portion is arranged such that an outer edge of the porous member is located more inward than an inner edge of the opening of the ring-shaped frame, The holding portion is disposed so that a portion that contacts the adhesive film protrudes further than a portion that contacts the ring-shaped frame. A wafer inspection device comprising:

2. The illumination unit and the imaging unit are disposed opposite to each other so that the illumination light transmitted through the wafer is incident on the imaging unit.

2. The wafer inspection device according to claim 1, wherein the holding portion includes an auxiliary support portion that supports the wafer inward from the outer edge portion, and the auxiliary support portion is made of a member through which the illumination light passes.

3. The holding portion is a height adjusting section for relatively changing the height of the contact surface of the auxiliary support section and the height of the contact surface of the porous member; 3. The wafer inspection device according to claim 2.

Images