This application claims benefit of priority, under 35 U.S.C. § 119, to Korean Patent Application No. 10-2019-0102565 filed on Aug. 21, 2019 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
The present disclosure relates to wafer inspection apparatuses.
In order to manage the quality of semiconductor wafers, an inspection process of the semiconductor wafers is performed during semiconductor wafer manufacturing.
In general, a vacuum chuck is used in a wafer inspection apparatus to hold a semiconductor wafer during inspection of the wafer. Most vacuum chucks apply a vacuum to a rear surface of a wafer to hold the wafer in place. Since a reflective inspection apparatus detects electromagnetic waves reflected from a front surface of a wafer, wafer measurement may not be disturbed even when a vacuum chuck is disposed on a rear surface of the wafer. However, in a transmissive inspection apparatus, electromagnetic waves cannot pass through a wafer region in contact with a vacuum chuck, and thus, there may be an unmeasurable region.
Some example embodiments provide a wafer inspection apparatus configured to increase in an inspection area of a wafer.
According to some example embodiments, a wafer inspection apparatus may include a support frame, an electromagnetic wave emitter, a sensor, and a driver. The support structure may include a frame, the frame including a plurality of vacuum chucks, each vacuum chuck of the plurality of vacuum chucks being mounted on the frame and each having a support surface including a vacuum suction portion. The support structure may be configured to structurally support a wafer on one or more vacuum chucks of the plurality of vacuum chucks, the frame defining an opening larger than an area of the wafer. The electromagnetic wave emitter may be configured to irradiate an inspection electromagnetic wave to the wafer. The sensor may be configured to receive the inspection electromagnetic wave from the wafer based on the inspection electromagnetic wave passing through the wafer. The driver may be configured to move at least one of the electromagnetic wave emitter or the frame to change an irradiation location of the wafer. Each vacuum chuck of the plurality of vacuum chucks may be configured to be selectively movable between a first location and a second location in relation to the frame.
According to some example embodiments, a wafer inspection apparatus may include a frame defining an opening, the frame configured to structurally support a wafer in the opening, wherein the opening is larger than an area of the wafer. The wafer inspection apparatus may include a plurality of first vacuum chucks and a plurality of second vacuum chucks. Each vacuum chuck of the plurality of first vacuum chucks and the plurality of second vacuum chucks may have a support surface including a vacuum suction portion. The plurality of first vacuum chucks and the plurality of second vacuum chucks may be configured to be movable between a first location of the frame and a second location of the frame. The support surface of each vacuum chuck may be configured to be coplanar with a reference plane for supporting the wafer when the vacuum chuck is at the first location of the frame. The wafer inspection apparatus may include an electromagnetic wave emitter configured to irradiate an inspection electromagnetic wave to a rear surface of the wafer, a sensor on the wafer, the sensor configured to receive the inspection electromagnetic wave from the wafer based on the inspection electromagnetic wave passing through the wafer, a driver configured to move the electromagnetic wave emitter to change an irradiation location on the rear surface of the wafer, and processing circuitry configured to control movements of the driver and the plurality of first and second vacuum chucks. The plurality of first vacuum chucks and the plurality of second vacuum chucks may be configured to be moved to the second location to deviate from a path of the inspection electromagnetic wave between the wafer and the electromagnetic wave emitter. The plurality of first vacuum chucks may be configured to be moved to the first location such that the support surfaces of the plurality of first vacuum chucks are in contact with first contact regions of the rear surface of the wafer, and the plurality of second vacuum chucks may be configured to be moved to the first location such that the support surfaces of the plurality of second vacuum chucks are in contact with second contact regions of the rear surface of the wafer, the first and second contact regions being different regions of the rear surface of the wafer.
According to some example embodiments, a wafer inspection apparatus may include a support structure including a frame. The frame may include a plurality of vacuum chucks. Each vacuum chuck of the plurality of vacuum chucks may be mounted on the frame and each vacuum chuck may have a support surface including a vacuum suction portion. The support structure may be configured to structurally support a wafer on one or more vacuum chucks of the plurality of vacuum chucks. The frame may define an opening larger than an area of the wafer. Each vacuum chuck may be configured to be positioned such that the support surface of the vacuum chuck is coplanar with a reference plane on which the wafer is supported by the support structure. The wafer inspection apparatus may include an electromagnetic wave emitter configured to irradiate an inspection electromagnetic wave to the wafer, a sensor configured to receive the inspection electromagnetic wave from the wafer based on the inspection electromagnetic wave passing through the wafer, and a driver configured to move at least one of the electromagnetic wave emitter or the frame to change an irradiation location of the wafer. Each vacuum chuck of the plurality of vacuum chucks may be configured to be separated from the reference plane to descend along the frame or to be flipped downwardly in relation to the frame.
The above and other aspects, features, and advantages of the present disclosure will be more clearly understood from the following detailed description, taken in conjunction with the accompanying drawings, in which:
Hereinafter, example embodiments will be described with reference to the accompanying drawings.
The wafer inspection system 300, illustrated in
As illustrated in
The wafer inspection apparatus 200 is a transmissive inspection apparatus analyzing characteristics of a wafer W using a manner in which inspection electromagnetic waves pass through the wafer W. In some example embodiments, the wafer inspection apparatus 200 includes a support structure 100 supporting a wafer W (e.g., structurally supporting a weight, or load, of the wafer W), an emission unit 140 (also referred to interchangeably herein as an electromagnetic wave emitter) configured to irradiate one or more inspection electromagnetic waves L1 to the wafer W, and a detection unit 160 (also referred to interchangeably herein as a sensor) on (e.g., over, isolated from direct contact with or in direct contact with) the wafer W and configured to receive (e.g., detect) one or more inspection electromagnetic waves L2 passing through the wafer W. The one or more inspection electromagnetic waves L2 may include at least a portion of the one or more inspection electromagnetic waves L2 irradiated to the wafer W, such that the detection unit 160 may detect an electromagnetic wave L2 from the wafer W based on the inspection electromagnetic wave L2 being irradiated to the wafer W as inspection electromagnetic wave L1 and passing through the wafer W as inspection electromagnetic wave L2.
An inspection electromagnetic wave, used in the wafer inspection apparatus 200, refers to an electromagnetic wave having a magnitude, or the like, varying depending on physical properties of a wafer W, an inspection target, after passing through the wafer W.
As illustrated in
In some example embodiments, the support structure 100 may include a base plate 121 and four support members 125 mounted on corners of the base plate 121 to support the frame 110. The frame 110 may be fixed to an upper end of the support members 125 by a fastening means 125P such as a screw or a pin.
The frame 110 may include three sides and may have a rectangular structure in which an open side is open, for example, a [-shaped structure. Restated, the frame 110 may include a rectangular frame, a circular frame, or a [-shaped frame. The wafer W may be loaded and unloaded through the open side of the frame 110 (indicated by “WR”). A shape of the frame 110 is not limited thereto, and the frame 110 may have various shapes such as a rectangle and a circle (see
The vacuum chucks 150A1, 150A2, 150A3, 150B1, 150B2, and 150B3, employed in some example embodiments, may be respectively configured to be movable along the frame 110, and may be divided into at least two groups (e.g., a plurality of groups of vacuum chucks), each group of vacuum chucks including three chucks, (a first group and a second group). Each group of the vacuum chucks 150A1, 150A2, 150A3 and 150B1, 150B2, and 150B3 may be mounted on three sides of the frame 120 to support (e.g., structurally support) the wafer W to be disposed on an opening OP. The opening OP may be defined by the frame 110 and may be configured such that the entire region of the wafer W is exposed to be inspected. In some example embodiments, the movement of the vacuum chucks 150A1, 150A2, 150A3 and 150B1, 150B2, and 150B3 may be performed for each group to increase a wafer inspection area, which will be described later with reference to
Each vacuum chuck of the plurality of vacuum chucks 150A1, 150A2, and 150A3 and 150B1, 150B2, and 150B3 may include a support surface 155 which may be in contact with a rear surface of the wafer W. While a vacuum chuck is in contact with the support surface 155, the inside of the vacuum chuck is brought into a vacuum state or a low-pressure state by a vacuum suction portion VH, such that a vacuum may be applied to a portion of the wafer W via the vacuum suction portion VH to at least partially hold the wafer W in place. Thus, the wafer W may be stably held on the support surface 155 during the wafer inspection process.
As illustrated in
In addition, the wafer inspection apparatus 200 may include a moving unit 130 (also referred to herein as a driver) that may move the emission unit 140 to change an irradiation location W1 of the wafer W (e.g., a location W1 on the rear surface Wb of the wafer W to which the inspection electromagnetic wave L1 is irradiated). The moving unit 130 may include, for example, a servo actuator, including a linear servo actuator. In some example embodiments, the moving unit 130 may move the frame in relation to the wafer W in order to change an irradiation location of the wafer W, in alternative to or in addition to moving the emission unit 140. Thus, it will be understood that the moving unit 130 may move at least one of the emission unit 140 or the frame 110 to change an irradiation location W1 of the wafer W to which an inspection electromagnetic wave L1 is irradiated by the emission unit 140.
As illustrated in
Referring to
As described above, a region NC, which cannot be analyzed due to a vacuum chuck, may include not only a region, which is in direct contact with the vacuum chuck, but also a neighboring region in which electromagnetic interference may occur.
In order to address such an issue, the plurality of vacuum chucks 150A1, 150A2, and 150A3 and 150B1, 150B2, and 150B3, employed in some example embodiments, may be configured to be selectively (for example, for each group) movable between a first location and a second location in the frame 110, as described above. Thus, it will be understood that the plurality of vacuum chucks 150A1, 150A2, and 150A3 and 150B1, 150B2, and 150B3, employed in some example embodiments, may be configured to be selectively (for example, for each group) movable between a first location and a second location in relation to the frame 110.
As shown in
Since a support surface 155 of each of the plurality of vacuum chucks 150A1, 150A2, 150A3, 150B1, 150B2, and 150B3 in the first location is disposed on (e.g., is coplanar with) a surface for supporting the wafer W (hereinafter referred to as “a reference plane P1”), electromagnetic waves, propagating to a contact region with the wafer W, may be blocked. The “reference plane P1” may be a plane that is coplanar with a rear surface Wb of the wafer W when the wafer W is structurally supported by the frame 110, and thus the wafer W may be described as being disposed on and/or supported on the reference plane P1 when the wafer W is supported (e.g., structurally supported) by the support structure 100.
As shown in
In some example embodiments, as illustrated in
As described above, the vacuum chucks 150A1, 150A2, and 150A3 and 150B1, 150B2, and 150B3 of each group may be arranged in appropriate locations of the frame 110 to support (e.g., structurally support) the wafers W to be inspected in the first location with balance.
In some example embodiments, the plurality of vacuum chucks 150A1, 150A2, 150A3, 150B1, 150B2, and 150B3 in the second location may be disposed to deviate from (e.g., move further away from) an electromagnetic wave path, also referred to as a path of the inspection electromagnetic wave L1, between the wafer W and the emission unit 140. The vacuum chucks 150A1, 150A2, and 150A3 and 150B1, 150B2, and 150B3 of the respective groups may be moved from the first location to the second location to reopen (e.g., expose) wafer regions, having been in contact with vacuum chucks, to enable emission unit 140 to irradiate an inspection electromagnetic wave L1 to the exposed wafer regions to enable inspection of the wafer regions. Accordingly, in some example embodiments, among the plurality of vacuum chucks 150A1, 150A2, and 150A3 and 150B1, 150B2, and 150B3, a first set of vacuum chucks selectively moved to the first location (e.g., 150A1, 150A2, and 150A3 as shown in
There may be various manners of moving a vacuum chuck between the first and second locations. In some example embodiments, the vacuum chucks 150A1, 150A2, 150A3, 150B1, 150B2, and 150B3 may each be moved in a flip manner so as to be separated from the reference plane P1 to be flipped downwardly in relation to the frame 110. In some example embodiments, the vacuum chucks 150A1, 150A2, 150A3, 150B1, 150B2, and 150B3 may each be moved in a flip manner so as to be separated from the reference plane P1 to descend (e.g., slide downwardly) along the frame 110.
For example, the vacuum chucks 150A1, 150A2, 150A3, 150B1, 150B2, and 150B3 in the first location may be disposed on internal sidewalls of the frame 110 to be parallel to the reference plane P1, and a support surface 155 of a vacuum chuck may face upwardly to be in contact with the wafer W. In some example embodiments, the vacuum chucks 150A1, 150A2, 150A3, 150B1, 150B2, and 150B3 in the second location may be flipped below the reference plane P1 to be separated from the internal sidewalls of the frame 110.
As illustrated in
Referring to
The first group of vacuum chucks 150A1, 150A2, and 150A3 may be disposed on the internal sidewalls of the frame 110 such that the support surface 155 faces upwardly, and may allow the wafer W to be supported by the support surface 155, as illustrated in
Since the first group (e.g., first set) of vacuum chucks 150A1, 150A2, 150A3 may cover a portion (or a support region) of a wafer, they interfere with a path of electromagnetic waves. Meanwhile, the second group of vacuum chucks 150B1, 150B2, and 150B3 do not interfere with a path of electromagnetic waves propagating to the wafer W.
Referring to
The second group of vacuum chucks 150B1, 150B2, and 150B3 may disposed on the internal sidewalls of the frame 110 such that the support surface 155 faces upwardly, and may allow the wafer W to be supported by the support surface 155. A wafer W, disposed on the support surface 155, may be adsorbed to the support surface 155 through vacuum suction. In some example embodiments, the first group of vacuum chucks 150A1, 150A2, and 150A3 may be flipped vertically below the reference plane P1 to deviate from the reference plane P1. In
In some example embodiments, as illustrated in
The vacuum chuck 150A1, moving in a flip manner, may further move from the second location to a lower surface of the frame 110 after moving to the second location, as illustrated in
As described above, the plurality of vacuum chucks 150A1, 150A2, and 150A3 and 150B1, 150B2, and 150B3 may be configured for each group to be movable between the first location and a second location in the frame 110.
While some example embodiments have been described as an example applied to a transmissive wafer inspection apparatus, some example embodiments may also be advantageously used in another manner (for example, a reflective manner), other than the transmissive manner, even when the measurement is disturbed by a vacuum chuck.
Hereinafter, an electromagnetic wave scanning process for wafer inspection and movement of a vacuum chuck for each group will be described.
Referring to
The first group of vacuum chucks 150A1, 150A2, and 150A3 may be disposed on internal sidewalls of the frame 110 such that a support surface 155 faces upwardly, whereas the second group of vacuum chucks 150B1, 150B2, and 150B3 may be flipped below a reference plane P1 on which a wafer W are to be disposed (see
In operation S62, the wafer W may be disposed on the first group of vacuum chucks 150A1, 150A2, and 150A3, and vacuum adsorption of the wafer W may be performed through the first group of vacuum chucks 150A1, 150A2, and 150A3.
Support surfaces 155 of the first group of vacuum chucks 150A1, 150A2, and 150A3 may be in contact with regions of a rear surface Wb of the wafer W, respectively. A wafer W, disposed on the support surface 155, may be adsorbed to the support surface 155 through vacuum suction. Electromagnetic waves cannot pass through such contact regions of the wafer W due to the first group of vacuum chucks 150A1, 150A2, and 150A3 (see
In operation S64, a first inspection may be performed by scanning the regions of the rear surface Wb of the wafer W, except for contact regions with the first group of vacuum chucks 150A1, 150A2, and 150A3, using electromagnetic waves.
As illustrated in
In operation S66, the second group of vacuum chucks 150B1, 150B2, and 150B3 may be moved to the first location, and vacuum suction of the wafer W may be performed through the second group of vacuum chucks 150B1, 150B2, and 150B3.
Thus, the wafer W, on which the first inspection finished to be performed, may be supported by the second group of vacuum chucks 150B1, 150B2, and 150B3 together with the first group of vacuum chucks 150A1, 150A2, and 150A3, as illustrated in
In operation S68, the first group of vacuum chucks 150A1, 150A2, and 150A3 may be moved to the second location after releasing a vacuum mode of the first group of vacuum chucks 150A1, 150A2, and 150A3.
As described above, since the wafer W is vacuum-adsorbed by the second group of vacuum chucks 150B1, 150B2, and 150B3, the first group of vacuum chucks 150A1, 150A2, and 150A3 may be moved to the second location, as illustrated in
When such a vacuum chuck is moved, for example, such a vacuum is in contact with the wafer W (for example, moved to the first location) and when separated from the wafer (for example, moved to the second location), it may be moved in a non-parallel direction from the wafer W, in detail, a direction perpendicular to a rear surface Wb of the wafer W to prevent contact and/or collision with the wafer W during movement of the vacuum chuck.
In operation S69, a second inspection is performed by additionally scanning wafer regions unscanned in the first scanning (e.g., the first contact regions R1).
The regions, scanned in this scanning process, may include a region, which was in contact with a vacuum chuck of the first chuck (e.g., first contact regions R1), and a region around the region. This may allow an entire region of a wafer W to be inspected.
As described above, the scanning process may be divided while selectively supporting a wafer using a plurality of movable vacuum chucks. Thus, a desired inspection may be performed up to an edge region of the wafer, and yield of devices in the vicinity of the wafer edge may be significantly improved.
The operations S61-S69 may be performed by the wafer inspection apparatus 200 based on the control unit 210 causes the wafer inspection apparatus 200 to perform one or more of said operations. For example, the control unit 210 may cause the wafer inspection apparatus 200 to perform a first process (e.g., at least operation S64), in which the emissions unit 140 and the moving unit 130 collective cause the inspection electromagnetic wave L1 to be irradiated to the rear surface Wb of the wafer W except for at least the first contact regions R1 while the first group of vacuum chucks 150A1, 150A2, and 150A3 are at the first location and the second group of vacuum chucks 150B1, 150B2, and 150B3 are at the second location. In addition, the control unit 210 may cause the wafer inspection apparatus 200 to perform a second process (e.g., at least operation S69), in which the emissions unit 140 and the moving unit 130 collective cause the inspection electromagnetic wave L1 to be irradiated to at least the first contact regions R1 (e.g., all regions of the wafer W not irradiated in the first process while the first group of vacuum chucks 150A1, 150A2, and 150A3 are at the second location and the second group of vacuum chucks 150B1, 150B2, and 150B3 are at the first location. In addition, the control unit 210 may cause the wafer inspection apparatus 200 to further perform a process between the first and second processes (e.g., operation S66) which the wafer inspection apparatus 200 causes the plurality of second vacuum chucks 150B1, 150B2, and 150B3 to structurally support the wafer W together with the plurality of first vacuum chucks 150A1, 150A2, and 150A3 based on stopping irradiation of the inspection electromagnetic wave L1 and moving the plurality of second vacuum chucks 150B1, 150B2, and 150B3 to the first location.
The movement of the vacuum chuck and the vacuum adsorption process and the inspection process (for example, the scanning process), illustrated in
In addition, in some example embodiments, the frame is described as a ⊏-shaped structure having three sides, but may have various shapes such as a square and a circle. As described above, the arrangement of the plurality of vacuum chucks and/or the shape of the frame may be variously changed.
Referring to
The plurality of vacuum chucks 150A1, 150A2, 150A3, 150B1, 150B2, and 150B3 may be divided into first and second groups, each having three vacuum chucks. The first group of vacuum chucks 150A1, 150A2, and 150A3 and the second group of vacuum chucks 150B1, 150B2, 150B3 include two pairs of vacuum chucks 150A2, 150A3, 150B2, and 150B3, disposed adjacent to each other (e.g., two pairs of adjacent vacuum chucks 150A2, 150A3, 150B2, and 150B3), and a pair of vacuum chucks 150A1 and 150B1 disposed to face each other (e.g., a pair of opposing vacuum chucks 150A1 and 150B1). As illustrated in
The first and second groups of the vacuum chucks 150A1, 150A2, and 150A3 and 150B1, 150B2, and 150B3 may be disposed to be rotationally symmetrical about a central axis of the wafer W. In some example embodiments, the first group of vacuum chucks 150A1, 150A2, and 150A3 may be disposed such that contact points (or first contact regions R1) of the wafer W form a substantially equilateral triangle, and the second group of vacuum chucks 150B1, 150B2, and 150B3 may be disposed such that contact point (or second contact regions R1) of the wafer W form a substantially inverted triangle, rotationally symmetrical by 180 degrees with respect to the disposition of the equilateral triangle of the first group of vacuum chucks 150A1, 150A2, and 150A3. Thus, the first and second contact regions R1 and R2 may be rotationally symmetrical about a central axis W-C of the wafer W.
The disposition of the vacuum chucks, illustrated in
Referring to
A plurality of vacuum chucks are not basically divided into two groups, and may be randomly combined to replace the selective support by the group described in some example embodiments.
For example, the wafer W is supported by first to third vacuum chucks 150A, 150B, and 150C (a first combination) disposed in a first location, and a first inspection is performed on a wafer region, except for regions in contact with the first to third vacuum chucks 150A, 150B, and 150C, while the wafer is supported by the first combination. Then, the wafer W is supported by first, second, and fourth vacuum chucks 150A, 150B, and 150D (a second combination) disposed in the first location, and a second inspection is additionally performed on a region in contact with the vacuum chuck 150C while the wafer W is supported by the second combination.
In a similar manner, third and fourth inspections may be performed on regions in contact with the first and second vacuum chucks 150A and 150B while the wafer W is supported by the other three vacuum chucks. Thus, the inspection may be performed on the entire area of the wafer W.
Setting of the first and second locations and movement of the first and second locations may be implemented in various forms. In some example embodiments, the vacuum chuck is illustrated as being moved in a flip manner. However, the vacuum chuck may be configured to be moved to the second location, for example, a region not overlapping (e.g., exposed by) a wafer W (for example, a corner region) along a track formed in a frame.
Referring to
As illustrated in
Vacuum chucks, employed in some example embodiments, may be moved along the track TRb provided in the frame 110′, as illustrated in
As illustrated in
As illustrated in
As shown in
As in some example embodiments, a movement of a vacuum chuck using a track may be similarly applied to a frame having a different shape and a vacuum chuck having a different disposition. For example, a vacuum chuck may be moved to a second location (for example, a corner region CR), not overlapping a wafer W, in the support structure illustrated in
As described above, according to example embodiments, a vacuum chuck may be configured to be movable. Thus, even a portion, covered with the vacuum chuck, may be measured by an additional inspection process. In particular, example embodiments may be advantageously used in a transmissive wafer inspection apparatus.
While some example embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the scope of the present inventive concepts as defined by the appended claims.
Number | Date | Country | Kind |
---|---|---|---|
10-2019-0102565 | Aug 2019 | KR | national |
Number | Name | Date | Kind |
---|---|---|---|
5736745 | Nagashima | Apr 1998 | A |
6126381 | Bacchi | Oct 2000 | A |
6439740 | Yan | Aug 2002 | B1 |
7108471 | Osuga | Sep 2006 | B2 |
7217934 | Mori | May 2007 | B2 |
10186446 | Weed | Jan 2019 | B2 |
11029256 | Ahn | Jun 2021 | B2 |
20060222477 | Moura | Oct 2006 | A1 |
20080318350 | Bhatnagar | Dec 2008 | A1 |
20090014127 | Shah et al. | Jan 2009 | A1 |
20100034621 | Martin | Feb 2010 | A1 |
20120314212 | Jang et al. | Dec 2012 | A1 |
20130162980 | Kim et al. | Jun 2013 | A1 |
20150014124 | Tagawa | Jan 2015 | A1 |
20160261786 | Ahn et al. | Sep 2016 | A1 |
20170352627 | Nakamura | Dec 2017 | A1 |
20180284071 | Wright | Oct 2018 | A1 |
20180364181 | Park et al. | Dec 2018 | A1 |
20190033233 | Amanullah et al. | Jan 2019 | A1 |
20190131145 | Tai et al. | May 2019 | A1 |
20190148212 | Lin et al. | May 2019 | A1 |
20210210365 | Freimuth | Jul 2021 | A1 |
Number | Date | Country |
---|---|---|
4230899 | Feb 2009 | JP |
10-2011-0055787 | May 2011 | KR |
10-2012-0105670 | Sep 2012 | KR |
10-2013-0072535 | Jul 2013 | KR |
10-2016-0080580 | Jul 2016 | KR |
10-2016-0107006 | Sep 2016 | KR |
10-2019-0049316 | May 2019 | KR |
10-2019-0049983 | May 2019 | KR |
10-2019-0051654 | May 2019 | KR |
Number | Date | Country | |
---|---|---|---|
20210057262 A1 | Feb 2021 | US |