TWI679414B - Workpiece detection device, film forming device, and workpiece detection method - Google Patents

Abstract

The present invention provides a workpiece detection device, a film forming device, and a workpiece detection method that can detect abnormalities in the position of a workpiece such as warpage by a common detection component without being affected by the surface properties of the workpiece. The workpiece detection device includes a first setting unit (42) that sets a first area (S1) of a predetermined size, and a second setting unit (43) that sets a larger area than the first area (S1) and sets the first area (S1) The second area (S2) included in all; the detection unit (44), which detects the image (Sw) of the reflected light from the wafer (W) housed in the holder (H) and which has been photographed corresponds to The value of the area of the area overlapped by the area between the first area (S1) and the second area (S2); and the determination unit (45) determines whether the value detected by the detection unit (44) exceeds a threshold Was there any abnormality in the position of the wafer (W) with respect to the holder (H)?

Description

Workpiece detection device, film forming device, and workpiece detection method

The invention relates to a workpiece detection device, a film forming device and a workpiece detection method.

In the manufacturing steps of various semiconductor devices, a multilayer film may be formed by laminating on a workpiece such as a wafer or a glass substrate. As a film forming apparatus for forming a multilayer film, there is a so-called multi-chamber type film forming apparatus including a plurality of chambers capable of reducing pressure. A target including a film-forming material is arranged in each chamber. An inert gas is introduced into the chamber, a voltage is applied to the target, and the inert gas is plasmatized to generate ions, and the ions are caused to hit the target. Film formation is performed by sputtering in which particles of a material hit from a target are deposited on a workpiece. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2008-244078

[Problems to be Solved by the Invention]

A workpiece to be formed into a film by sputtering is transferred to a film forming apparatus while being placed in a holder. The workpiece that has been placed in the holder may not be fixed in position or inclination, and may be exposed from the holder. The distance between the workpiece exposed to a large extent from the holder, the target, and the plasma is not fixed within the film formation surface, and uniform film formation cannot be performed.

In order to cope with this problem, a method of detecting a position such as the outer periphery of the workpiece using a laser sensor or the like, and determining a position abnormality based on a deviation amount from a position serving as a reference may be considered. However, the surface properties of the workpiece differ depending on the material. For example, the transmittance or reflectance of light of a semiconductor wafer varies depending on whether the material is silicon (Si) or silicon carbide (SiC), whether a pattern is formed, or whether a film is formed. If, for example, a plurality of wafers with different surface properties are to be detected by a common sensor, the values of the most appropriate sensitivity and the like in each wafer detection are different. Therefore, the value must be changed whenever the wafer is changed. In addition, there are cases where it is difficult to know the most appropriate value such as the sensitivity in the detection of each wafer. To cope with this problem, it is unrealistic to increase the cost by providing sensors suitable for each wafer corresponding to wafers having different surface properties.

Therefore, a method may be considered in which an arbitrary image that has been reflected on a wafer is captured by a camera, and the center position of the image of the captured arbitrary image is obtained, and based on this center position and a center set as a reference in advance The position deviation is used to detect an abnormality in the position of the workpiece (see Patent Document 1).

However, there are very thin wafers in the wafer. For example, in the field of power devices, electronic circuits such as Metal Oxide Semiconductor Field Effect Transistors (MOS-FETs) are formed in advance on the wafer, and then the back surface is cut to be very thin, and then processed. It is transported to a film forming apparatus, and aluminum (Al) which becomes an electrode is formed into a film on a back surface. Such thin wafers can warp or warp. This warped or twisted shape differs from wafer to wafer. Therefore, even with wafers of the same diameter, even if the wafers are located at the correct position, the center position is not fixed. Therefore, it is not only difficult to set the center position of the wafer serving as a reference, but also it is difficult to determine the amount of shift based on the set center position.

An object of the present invention is to provide a workpiece detection device, a film forming device, and a workpiece detection method that can detect abnormalities in the position of a workpiece such as warpage by a common detection member without being affected by the surface properties of the workpiece. [Means for solving problems]

In order to achieve the above object, the workpiece detection device of the present invention includes a first setting unit that sets a first area of a predetermined size; a second setting unit that sets a size larger than the first area, and sets all of the first area Included second area; a detection unit that detects an image of reflected light from a workpiece that is housed in a holder and has been captured, corresponding to an area that overlaps an area between the first area and the second area A value of the area; and a determination unit that determines whether there is an abnormality in the position of the workpiece with respect to the holder, based on whether or not the value detected by the detection unit exceeds a threshold.

The size of the first area may be a size that incorporates an image of reflected light from a workpiece stored in a normal position of the holder. The first region and the second region may be concentric circles.

An input unit may be provided to instruct setting of the first area using the first setting unit, and the second setting unit may set the first area corresponding to the setting of the first area using the input unit. 2 areas.

A display section may be provided to display information corresponding to the area. The display unit may display the abnormal information.

There may be a single light source for irradiating the workpiece with light, and an imaging unit for capturing reflected light from the workpiece.

In addition, the film forming apparatus of the present invention includes: the workpiece detecting device; and a film forming section that forms a film on a workpiece whose position has been determined to be abnormal by the workpiece detecting device.

In addition, in the workpiece detection method of the present invention, a computer or an electronic circuit executes the following processes: a first setting process to set a first area of a predetermined size; a second setting process to set a larger area than the first area, and A second area that includes all of the first area; a detection process that detects an image of the reflected light from the workpiece corresponding to an area value of an area overlapping the area between the first area and the second area And a determination process, based on whether or not a value detected by the detection process exceeds a threshold value, it is determined whether there is an abnormality in the position of the workpiece with respect to the holder. [Effect of the invention]

According to the present invention, it is possible to detect an abnormality in the position of a workpiece, such as warping, by a common detection member without being affected by the surface properties of the workpiece.

An embodiment of the present invention will be specifically described with reference to the drawings. (Wafer) In this embodiment, as shown in FIG. 1 (A) and FIG. 1 (B), an example in which a wafer W using a semiconductor is used as a workpiece for a film formation object will be described. The wafer W has a circuit formed on its surface before the film formation step, and the back surface is polished. In recent years, wafer W has been polished to a thickness of several tens of μm due to a tendency of thinning due to high integration. In this way, the wafer W is formed very thinly, so that warpage or distortion occurs. In the film forming step, a film is formed on the polished surface.

(Fixer) In this embodiment, the wafer W to be formed is used as a mounting member. As shown in FIGS. 2 (A) and 2 (B), a clamper H is used. The holder H is a member having a bottomed cylindrical shape having a rectangular cross section after being cut on the A-A cut surface, and has a receiving portion Hs having a size that accommodates the wafer W inside. An opening Ho having a smaller diameter than the wafer W is formed at the bottom of the holder H. Therefore, the outer periphery of the surface of the wafer W can be supported by the bottom of the edge of the opening Ho. In addition, the opening Ho is a size that can be inserted into and ejected from the elevation plate 232 and the elevation shaft 233 (see FIG. 5).

(Film Forming Apparatus) (Outline) As shown in FIG. 3, the film forming apparatus 100 according to this embodiment includes an atmospheric loader 200, a film forming section 300, and a control device 400.

The atmospheric loader 200 is a structural part that mounts the wafer W in the holder H and carries it into the film forming part 300. The film forming section 300 is a structural section that forms a film by sputtering on the wafer W that has been placed in the holder H. The control device 400 is a device that controls each part of the film forming apparatus 100. Hereinafter, details of each part of the film forming apparatus 100 will be described.

(Atmospheric Loader) The atmospheric loader 200 includes a holder supply unit 210, a wafer supply unit 220, and a detection mechanism 230. Although not shown, the holder supply unit 210 includes a holder box and a transfer arm in which a plurality of holders H are stacked and stored. The wafer supply unit 220 includes a wafer cassette and a transfer arm in which a plurality of wafers W are stacked and stored. The detection mechanism 230 is a structural part that images the wafer W placed in the holder H.

The holder H removed from the holder box of the holder supply unit 210 by the transfer arm is provided in the detection mechanism 230. The wafer W taken out from the wafer cassette of the wafer supply unit 220 is placed in a storage portion Hs of a holder H provided in the detection mechanism 230. The wafer W is carried into the film forming unit 300 by a transfer arm (not shown) in a state where the wafer W is placed in the holder H.

As shown in FIG. 4, the detection mechanism 230 includes a support base 231, a lifting plate 232, a lifting shaft 233, a support post 234, and an imaging unit 235. The support table 231 is a table on which the holder H is placed. An opening 231 a corresponding to the opening Ho of the holder H is provided in the support base 231. The elevating plate 232 is a plate-like body that can advance and retreat in the vertical direction from the lower side of the support base 231 through the opening 231 a and the opening Ho.

The lifting shaft 233 is a rod-shaped member connected at one end to the lifting plate 232. The other end of the lifting shaft 233 is connected to a driving source (not shown). The driving source raises and lowers the lifting shaft 233. As the driving source, for example, an air cylinder can be used.

As shown in FIG. 5, the lift shaft 233 enters through the opening 231 a of the support table 231 and the opening Ho of the holder H, and the lift plate 232 that has risen further receives the wafer W that has come above the holder H. As shown in FIG. 6, the lifting plate 232 is lowered to store the wafer W in the receiving portion Hs of the holder H. The pillar 234 is a member on which a beam is mounted on two columnar members that are erected from both sides of the support base 231. The direction of the beam is parallel to the diameter of the holder H and extends across the support base 231 Way configuration.

The imaging unit 235 includes a camera 21 and a light source 22. As shown in FIG. 7, the camera 21 is an imaging device including an optical member such as a lens and a light receiving element such as a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor (CMOS) or a charge coupled device (CCD)) The image sensor outputs a signal corresponding to the light detected by the light receiving element via the optical member. The light source 22 is an illumination device such as a light emitting diode (LED) that irradiates light to the wafer W. In this embodiment, as shown in FIG. 7, one light source 22 is provided at a position adjacent to the optical member of the camera 21. The light source 22 may irradiate the entire wafer W, but it is not necessary to irradiate the entire wafer W. For example, in this embodiment, the wafer W is irradiated with light having a diameter of about 10 mm.

As shown in FIGS. 8A and 8B, an image of the reflected light from the wafer W captured by the camera 21 is displayed on a screen of a display unit 49 described later. The image of the reflected light from the wafer W refers to an image formed by detecting light reflected from the light source 22 to the wafer W using a light-receiving element. The area surrounded by the outline of the edge. Hereinafter, an image of the reflected light from the wafer W is referred to as an image Sw of the reflected light. Regardless of the wafer W that is totally reflective, transparent, or translucent, the contour of the outer edge corresponding to the reflected light can be captured with a brightness that can be recognized from the background. Therefore, it is possible to extract an area of a light amount equal to or greater than a preset threshold value as an image Sw of reflected light.

(Film-forming section) As shown in FIG. 3, the film-forming section 300 has a multi-chamber structure in which a plurality of chambers 30 are arranged along each side of the vacuum transfer chamber 310 with the hexagonal columnar vacuum transfer chamber 310 as the center. . At least one of the plurality of chambers 30 is a film formation chamber for forming a film on the wafer W. The number of film forming chambers is determined in accordance with the number of films formed on the wafer W, and is not limited to a specific number. In addition, any one of the chambers 30 may be a chamber that performs processes other than film formation, such as a cooling chamber, a heating chamber, and an etching chamber.

In this embodiment, as an example, the chamber 30 is set to five film-forming chambers 321 to 325 and one workpiece lockout chamber 326. In addition, the shape of the vacuum transfer chamber 310 is not limited to a hexagonal columnar shape, and may be a polygonal shape corresponding to the required number of the film forming chambers 321 to 325 or a cylindrical shape.

The work loading / unloading chamber 326 is a chamber for carrying in the holder H from the atmospheric loader 200 from the outside, and carrying out the holder H which has completed the film forming process to the atmospheric loader 200. One side surface of the work access chamber 326 is connected to the vacuum transfer chamber 310 via a vacuum gate valve 326a, and the other side surface is connected to the atmospheric loader 200 via an air gate valve 326b. By opening and closing the vacuum gate valve 326a, it is possible to switch between communication and blocking with respect to the vacuum transfer chamber 310. By opening and closing the air gate valve 326b, communication and blocking can be switched with respect to the air loader 200.

A holding portion (not shown) that holds the wafer W that has been carried in is provided inside the workpiece loading / unloading chamber 326. An exhaust device and a pressure gauge (not shown) are provided in the work access chamber 326 to reduce the pressure to a desired pressure.

The vacuum transfer chamber 310 is a chamber for transferring wafers W into and out of each of the film forming chambers 321 to 325 into the workpiece loading and unloading chamber 326. In addition, an exhaust device and a pressure gauge (not shown) are provided in the vacuum transfer chamber 310 and can be reduced in pressure to a desired pressure.

A center of the vacuum transfer chamber 310 is provided with a transfer arm 311 for transferring the wafer W. The transfer arm 311 extends into the workpiece loading / unloading chamber 326 and each of the film forming chambers 321 to 325, takes out the wafer W from each of the chambers, transfers the wafer W into the vacuum transfer chamber 310, and further transfers into another chamber.

When carrying in and carrying out, the plurality of film forming chambers 321 to 325 open the respective vacuum gate valves 321a to 325a. During processing, the vacuum gate valve 321a to the vacuum gate valve 325a are closed, and the interior of each chamber is hermetically closed. In each of the film forming chambers 321 to 325, a film is formed on the wafer W. Each of the film forming chambers 321 to 325 may be configured in the same manner, or may have different configurations.

Here, the structure of the film formation chamber 321 will be described as an example with reference to FIGS. 9 and 10. The film formation chamber 321 includes a chamber 30, a platform 31, a lifting mechanism 32, and a sputtering source 33. The chamber 30 is a container that can be evacuated inside. The chamber 30 is provided with a pressure gauge 30a and an exhaust device (not shown). The inside of the chamber 30 is always exhausted by an exhaust device, and is managed so as to be in a predetermined decompressed state. A gas introduction portion 30 b is provided in the chamber 30. A sputtering gas can be introduced into the chamber 30 from the gas introduction part 30b. As the sputtering gas, for example, an inert gas such as argon can be used.

The stage 31 is a member provided near the inner bottom of the chamber 30 and on which the holder H that houses the wafer W is placed. The platform 31 has a circular plate shape, and is connected to and supported by a shaft 31 a extending from the bottom surface of the chamber 30. The shaft 31a penetrates the bottom surface of the chamber 30 in an airtight manner and communicates with the outside.

The center portion of the platform 31 projects so that the cross section has a convex shape. The upper surface of the center portion enters through the opening Ho of the holder H, and thereby becomes a flat mounting surface on which the wafer W is mounted. This mounting surface constitutes an electrostatic chuck 31b. The electrostatic chuck 31b includes a metal base member and a ceramic dielectric. The mounting surface of the wafer W is the upper surface of the dielectric.

An electrode is provided inside the dielectric. When a voltage is applied to the electrode, an electrostatic force is generated between the mounting surface and the wafer W mounted thereon, and the wafer W is adsorbed and fixed on the upper surface of the dielectric. In order to supply power to the electrodes inside the dielectric, a cable is passed through the inside of the shaft 31 a of the platform 31 and connected to a power supply source (not shown) provided outside the chamber 30. In addition, a cooling mechanism (not shown) is provided on the platform 31, and the platform 31 is provided so that the platform 31 can be cooled by the cooling mechanism.

The lifting mechanism 32 is provided near the bottom of the chamber 30. The elevating mechanism 32 includes a lever 32a, a stage 32b, and a pin 32c. The rod 32 a penetrates the bottom of the chamber 30 in an airtight manner, and is connected to a driving mechanism (not shown) such as a cylinder device or a motor outside the chamber 30. Driven by this drive mechanism, the lever 32 a is raised and lowered inside the chamber 30.

The stage 32b is mounted on the upper end of the rod 32a. The stage 32 b is, for example, a circular plate shape, and is arranged substantially parallel to the stage 31 below the stage 31. A through hole is formed in the center of the stage 32b. The shaft 31a of the platform 31 is inserted through the through hole. As the rod 32a is raised and lowered, the table 32b moves up and down relative to the platform 31 and the shaft 31a.

A plurality of pins 32c are vertically provided on the upper surface of the stage 32b. Although not shown, the platform 31 is formed with guide holes penetrating in the vertical direction of the chamber 30 in accordance with the number of pins 32 c. Each pin 32c is inserted into these guide holes, and moves up and down as the stage 32b moves up and down.

As shown in FIG. 9, these pins 32c are raised to receive and hold the holder H which has been carried in from the vacuum transfer chamber 310 by the transfer arm 311. As shown in FIG. 10, these pins 32c are lowered to place the holders on the holder The wafer W of H is transferred to the electrostatic chuck 31 b which is the upper surface of the stage 31. Therefore, the pin 32c is set so as to rise at least to the receiving position where the holder H is received from the transfer arm 311. In addition, the upper end of the pin 32 c is set so as to be lowered at least to the same position as the upper surface of the guide hole of the platform 31. The upper surface of the stage 31 is a film formation position where a film is formed on the wafer W.

The sputtering source 33 is a supply source of a film forming material deposited on the wafer W to form a film. The sputtering source 33 is disposed on the upper portion of the chamber 30. The sputtering source 33 includes a target 33a, a backing plate 33b, and a conductive member 33c.

The target 33a is, for example, mounted on the upper surface of the chamber 30, and is arranged so that its surface faces the platform 31 provided near the bottom of the chamber 30. The target 33a includes a film-forming material, and all known film-forming materials can be applied, and for example, titanium, silicon, or the like can be used. The shape of the target 33a is, for example, a cylindrical shape. However, other shapes such as an elliptical column shape and a corner column shape may be used.

The back plate 33b is a member that holds the target 33a on the side opposite to the platform 31. The conductive member 33c is a member that applies electric power to the target 33a from the outside of the chamber 30 via the back plate 33b. A magnet, a cooling mechanism, and the like are provided in the sputtering source 33 as necessary.

A power source 34 is connected to the sputtering source 33. The power source 34 applies electric power to the target 33a, thereby plasmatizing the sputtering gas that has been introduced into the surroundings of the target 33a. The power source 34 in this embodiment is, for example, a direct current (DC) power source to which a high voltage is applied. In addition, in the case of a device performing high-frequency sputtering, a radio frequency (RF) power source may be used.

After the sputtering gas is introduced into the chamber 30, a DC voltage is applied from the power source 34 to the target 33a. The sputtering gas is plasmatized by the application of a DC voltage and generates ions. When the generated ions collide with the target 33a, the material of the target 33a will fly out as particles. The flying particles are deposited on the wafer W placed on the stage 31, and a thin film is formed on the wafer W.

The control device 400 is a device that controls each of the atmospheric loader 200 and the film forming section 300. The control device 400 may include, for example, a dedicated electronic circuit or a computer operating in a predetermined program. The control content of each unit is written in the control device 400 and executed by a processing device such as a programmable logic controller (PLC) or a central processing unit (CPU). Thereby, it can respond to various film-forming specifications.

The configuration of such a control device 400 will be described with reference to FIG. 11 which is a virtual functional block diagram. That is, the control device 400 includes a mechanism control section 40, a display processing section 41, a first setting section 42, a second setting section 43, a detection section 44, a determination section 45, a memory section 46, and an input / output control section 47.

The mechanism control unit 40 is a processing unit that controls the mechanism of each unit. The controlled mechanisms include, for example, a holder supply unit 210, a wafer supply unit 220, a transfer arm (not shown), a drive source of the lifting shaft 233 of the detection mechanism 230, a camera 21 of the imaging unit 235, a light source 22, and a vacuum. Gate valve 321a to vacuum gate valve 325a, vacuum gate valve 326a and atmospheric gate valve 326b, vacuum transfer chamber 310, film formation chamber 321 to film formation chamber 321 and film formation chamber 325, and exhaust device for workpiece access chamber 326, transfer arm 311 of vacuum transfer chamber 310, film formation The gas introduction part 30b, the power supply 34, and the raising-lowering mechanism 32 of the chamber 321-the film-forming chamber 325.

The display processing unit 41 performs display processing of an image captured by the imaging unit 235. That is, as shown in FIGS. 8A and 8B, the image Sw of the reflected light captured by the imaging unit 235 is displayed on the display screen of the display unit 49. The display processing unit 41 controls the display of the first region S1, the second region S2, and the detection region D described later.

As shown in FIG. 8 (A), the first setting unit 42 sets a first area S1 of a predetermined size. In the present embodiment, the predetermined size is a size including the image Sw of the reflected light. In the present embodiment, the first region S1 is circular. The size of the reflected light image Sw may be greater than or equal to the size of the reflected light image Sw. As shown in FIG. 8 (B), the wafer W is in a state where it has been punched in the receiving portion Hs. The position where the light is irradiated is shifted, so that the image Sw of the reflected light actually captured can also be separated from the first area S1. However, each time the first setting unit 42 replaces the wafer W as an object with a different material or a wafer W formed with a different pattern, it incorporates the reflected light from the wafer W located at a normal position. The position setting first area S1. In addition, the overshoot refers to a state in which a part of the outer periphery of the wafer W contacts the side surface of the accommodation portion Hs or the upper surface of the holder H, and the wafer W has been inclined. For example, states such as (B), (D), (E), and (F) of FIG. 13 are referred to as an overshoot state. The state in which the container Hs has been punched upward refers to a state such as (B) and (D).

In addition, depending on the state of warpage of the wafer W, there is a possibility that the position shift amount of the reflected light image Sw caused by the reflection of light, that is, the offset may increase, so it is preferable to consider the As described above, the first region S1 is set to be larger than the wafer W.

The second setting unit 43 sets a second area S2 that is larger than the first area S1 and includes all of the first area S1. In the present embodiment, the second region S2 is a concentric circle having a larger diameter than the first region S1. Therefore, as shown in FIG. 12, if the diameter of the image Sw of the reflected light is α, the diameter of the first region S1 is β, and the diameter of the second region S2 is γ, α ≦ β < γ.

The detection unit 44 detects that the image Sw of the reflected light corresponds to the value of the area of the area overlapping the area between the first area S1 and the second area S2. The area that has been detected as described above is referred to as a detection area D. That is, the detection unit 44 extracts a region of the light amount equal to or greater than a preset threshold as an image Sw of the reflected light, and extracts the image Sw of the extracted reflected light and the region between the first region S1 and the second region S2. The overlapping area is set as the detection area D. The value corresponding to the area of the detection area D can be obtained, for example, from the sum of the number of pixels in the portion overlapping the area between the first area S1 and the second area S2. The value corresponding to the area refers to a value that increases or decreases in proportion to the area, and may be the value of the number of pixels itself, or the value of the area calculated from the number of pixels. The value of the area may be an area value on a screen, or an actual area value calculated based on the number of pixels and the scale of the shooting area.

The determination unit 45 determines whether or not the position of the wafer W with respect to the holder H is abnormal based on whether the value detected by the detection unit 44 exceeds a threshold value. The area of the detection area D varies depending on the amount of overshoot of the wafer W. The area of the detection area D shown when the offset occurs varies depending on the type of the wafer W, such as a difference in surface properties. Therefore, the thresholds for identifying whether the detection area D is normal or abnormal are different.

For example, as shown in FIG. 13, (A) to (D) are cases where the wafer W is not exposed from the accommodation portion Hs, and (E) to (F) are cases where the wafer W has been exposed from the accommodation portion Hs. (A), (B), and (E) are the cases where the wafer W has a warpage protruding downward, and (C), (D), and (F) are the cases where the wafer W has a warpage protruding upward. . In the present embodiment, in the cases of (A) to (D), it is allowed as OK, that is, normal, and in the cases of (E), (F), it is not allowed as NG, that is, abnormal.

If the wafer W is transferred to the stage 31 in the states (E) and (F) of FIG. 13, there is a concern that the wafer W cannot be sucked by the electrostatic chuck 31 b. In addition, even if it can be sucked, the wafer W is placed in a state in which the position is shifted from the normal position of the platform 31, so the portion of the wafer W that is not in contact with the platform 31 is not sufficiently cooled by the platform 31 and is heated. . In addition, there is a concern that the film to be formed is adhered to the upper surface of the stage 31 on which the wafer W is not placed.

However, as shown in FIG. 14, even if the overshoot amount p of the wafer W is the same, the area of the detection area D varies depending on the type of the wafer W. The reason for this is that the reflectance of light and the like vary depending on the surface properties of the wafer W, and therefore there are cases where the outline is clear or blurred, and the size of the captured reflected light image Sw is not fixed. For example, the relationship between the amount of overshoot of the wafer W and the value detected by the detection unit 44 is shown in FIG. 15. The circles, squares, and triangles in FIG. 15 indicate wafers W having different surface properties.

For each wafer W, the value detected by the detection unit 44 is obtained as a detection value as follows. The wafer W is mounted on the holder H in a state of a predetermined upward punch, and is mounted on the support table 231 of the detection mechanism 230. Then, the holder H is rotated 360 degrees in units of 30 degrees to capture 12 images Sw of reflected light. A detection value corresponding to the value of the area of the detection area D is obtained from the captured image Sw of each reflected light.

Regarding the detection value of each wafer W, the upper limit value of the detection value of each wafer W is indicated by each mark at the upper punch amount a and the upper punch amount b. At the upper impulse amount c, each mark indicates the lower limit value of the detection value of each wafer W. An error bar is used to represent the distribution of the detection values in the same wafer W. If the error bars of each wafer W are displayed, they will overlap. Therefore, in FIG. 15, the distribution of all detected values at a certain upper impulse is shown in the form of error bars. These error bars are referred to as error bars EB1, EB2, and EB3.

When the detection values of the wafers W indicated by the marks are compared at the respective overshoot amounts a, b, and c, the detection values become different values even with the same overshoot amount. The reason is considered to be due to the difference in surface properties. In addition, even in the detection value of the same wafer W, there is a difference in the deviation. The reason for this is considered to be that the wafer W is warped.

For example, when the overshoot amount c is greater than the upper limit value (circle value) of the detection value of the error bar EB2 when it is exposed from the holder H, that is, if it is determined to be abnormal, it is larger than the error bar Among the detection values of EB3, a value having a lower lower limit value (square value) is set as the threshold value Th1.

If a value larger than the upper limit value of the error bar EB2 is set as the threshold value Th1, when the detection value is less than Th1, the processing is performed as a person who has stored the wafer W in the storage portion Hs. As a result, it is possible to prevent a decrease in productivity caused by frequent stop processing, which is determined to be abnormal, although not exposed from the holder H. In addition, when a value smaller than the lower limit value of the detection value of the error bar EB3 is set as the threshold value Th1, the possibility that the wafer W exposed from the holder H is carried into the film forming section 300 can be reduced. Safety is ensured. This is suitable when the difference between the upper limit value of the error bar EB2 and the lower limit value of the error bar EB3 is large.

When the difference between the upper limit value of the error bar EB2 and the lower limit value of the error bar EB3 is small, a value within the range of the error bar EB2, for example, a value of a square mark may be set as the threshold value Th2. In this case, although it was not exposed from the holder H, it was judged that it was abnormal and the processing was stopped, and safety was ensured in spite of this.

The storage unit 46 is a structural unit that stores information required for control in the present embodiment. This information includes: the shooting timing of the camera 21 of the imaging section 235, the light amount of the light source 22, the setting conditions of the first area S1 set by the first setting section 42, and the The conditions, the detection value of the detection unit 44, the threshold value of the determination by the determination unit 45, and the determination result are set. The setting conditions of the second region S2 include a difference between the diameter of the first region S1 and the diameter of the second region S2. The mechanism control unit 40 generates control signals for each unit based on the information stored in the memory unit 46 and outputs the control signals.

The memory unit 46 may include, for example, various memories, a hard disk, and the like. A storage medium used as a temporary storage area is also included in the storage unit 46. A video random access memory (VRAM) or the like for image display can also be adopted as the memory section 46. The input / output control unit 47 is an interface that controls conversion or input / output of signals between various units that are to be controlled.

Furthermore, an input unit 48 and a display unit 49 are connected to the control device 400. The input unit 48 is an input device such as a switch, a touch panel, a keyboard, and a mouse for the operator to operate the film forming apparatus 100 via the control device 400. An instruction to set the first region S1 by the first setting unit 42, a difference between the diameter of the second region S2 and the diameter of the first region S1, a threshold value of the determination by the determination unit 45, and the like can be input from the input unit 48. The second setting unit 43 sets the second region S2 based on the instruction for setting the first region S1 from the input unit 48 and the setting conditions of the second region S2.

The display unit 49 is an output device such as a display, a lamp, or a meter, and information for confirming the state of the device becomes a state that can be recognized by the operator. The display displays information on the area of the detection area D on the display screen. The information indicating the area of the detection area D may be an image indicating the detection area D, or a numerical value of the area of the detection area D, or both.

For example, as shown in FIG. 8 (A), if the operator specifies an arbitrary point on the display screen outside the image Sw of the reflected light at the time of normal display through the input unit 48, the first setting unit 42 sets A first area S1 having a size including the image Sw of the reflected light is set through the locus of the designated point. Furthermore, the second setting unit 43 sets a concentric circle with a diameter that is only a set length larger than the diameter of the first region S1 according to the setting conditions as the second region S2.

In this way, the display of the display unit 49 displays the reflected light image Sw, the first region S1, and the second region S2 on the display screen. As shown in FIG. 8 (B), the area in the reflected light image Sw that overlaps with the area between the first area S1 and the second area S2 is the detection area D. Moreover, the display shows the determination result of the determination part 45. For example, if it is determined to be abnormal, the detection area D is displayed in a color separation that is distinguished from other areas. It is also possible to include an output device that reports the above information by sound.

[Operation] Next, an operation of the film forming apparatus 100 according to this embodiment will be described. A detection method for detecting an abnormality in the position of the wafer W by the following program is also an aspect of the present invention. That is, as shown in FIG. 4, the holder H that has been taken out from the holder supply unit 210 by the transfer arm is placed on the support base 231 of the detection mechanism 230. On the other hand, the wafer W that has been taken out from the wafer supply unit 220 by the transfer arm is transferred above the holder H placed on the support table 231.

The lift plate 232 rises and receives the wafer W from the transfer arm as shown in FIG. 5. Then, the lifting plate 232 is lowered, and the wafer W is placed in the receiving portion Hs of the holder H. In addition to the drawings, a process of detecting the offset of the wafer W placed in the holder H as described above will be described with reference to the flowchart of FIG. 16.

(Area Setting Process) The process of setting the first area S1 and the second area S2 will be described. First, the wafer W is irradiated with light from the light source 22 at a normal position with respect to the holder H, and the camera 21 captures the reflected light (step 101). As shown in FIGS. 8 (A) and 8 (B), the captured image of the wafer W is displayed on a display screen of a display (step 102).

The worker views the image of the wafer W displayed on the display, and specifies the outside of the outline of the wafer W (step 103). Then, the first setting unit 42 sets a circle passing through the designated point and including the image of the wafer W as the first region S1 (step 104). In addition, the second setting unit 43 sets the concentric circles included in the first region S1 as the second region S2 (step 105). The set first area S1 and second area S2 are displayed on the display.

(Detection Processing) Next, processing for detecting an abnormality in the position of the wafer W will be described based on the set first and second regions S1 and S2. As described above, the light source 22 irradiates light to the wafer W that has been stored in the housing portion Hs of the holder H, and the camera 21 captures the reflected light (step 106).

The captured image W of the reflected light of the wafer W overlaps the first region S1 and the second region S2 and is displayed on the display (step 107). The detection unit 44 detects that the image Sw of the reflected light captured by the camera 21 corresponds to the value of the area of the area overlapping the area between the first area S1 and the second area S2 (step 108).

The determination unit 45 determines whether the detected value exceeds a threshold value (step 109). A graph as shown in FIG. 15 is prepared based on prior experiments to determine the threshold. When the threshold value is exceeded (YES in step 109), since the amount of displacement is large and the amount of exposure from the storage portion Hs is large, it is determined to be abnormal (step 110). When the abnormality is determined, the display shows abnormality information (step 111), and the atmospheric loader 200 and the film forming unit 300 stop operating (step 112).

In this case, after the operator corrects the position of the wafer W on the holder H, the operations of the atmospheric loader 200 and the film forming unit 300 are started. Alternatively, the wafer W on the holder H is taken out. When the threshold value is not exceeded (NO in step 109), the detection process ends. Such detection processing is sequentially performed on the holder H placed on the detection mechanism 230.

(Film Forming Process) Next, a film forming process of the wafer W whose position has been corrected as described above or the wafer W having a normal position will be described. First, the air gate valve 326 b is opened, and the holder H on which the wafer W is placed is carried into the work loading / unloading chamber 326 by a transfer arm.

At this time, under the atmospheric pressure of the work access chamber 326, the vacuum gate valve 326a on the vacuum transfer chamber 310 side is closed. When the transfer arm that has carried in the wafer W withdraws from the work access chamber 326, the atmospheric gate valve 326b is closed. Then, the work access chamber 326 is evacuated and decompressed to a predetermined pressure. When the decompression is completed, the vacuum gate valve 326 a of the work access chamber 326 is opened to communicate with the vacuum transfer chamber 310. The vacuum transfer chamber 310 is decompressed in advance.

The transfer arm 311 of the vacuum transfer chamber 310 is made to enter the workpiece access chamber 326. The transfer arm 311 holds the holder H and carries it into the vacuum transfer chamber 310. When the loading is completed, the vacuum gate valve 326 a connecting the workpiece loading / unloading chamber 326 and the vacuum transfer chamber 310 is closed.

Next, the vacuum gate valve 321 a of the film formation chamber 321 adjacent to the work entrance / exit chamber 326 is opened, and the transfer arm 311 holding the holder H is entered into the chamber 30. As shown in FIG. 9, the elevating mechanism 32 of the film forming chamber 321 raises the plurality of pins 32 c to the receiving position in accordance with the timing of entry of the conveying arm 311.

The transfer arm 311 mounts the held holder H on the upper end portion of the pin 32c. After being placed, the transfer arm 311 is retracted from the film forming chamber 321, and the vacuum gate valve 321a connecting the vacuum transfer chamber 310 and the film forming chamber 321 is closed.

When the vacuum gate valve 321 a is closed, the lifting mechanism 32 is operated, and the pin 32 c is lowered to the platform 31. Thereby, the holder H is placed on the platform 31. Then, as shown in FIG. 10, the mounting surface of the stage 31 enters through the opening Ho of the holder H and contacts the wafer W. In the electrostatic chuck 31b on the mounting surface, an electrostatic force is exerted by applying electricity, and thus the wafer W is suction-fixed to the upper surface of the electrostatic chuck 31b.

When the inside of the chamber 30 is decompressed to a predetermined pressure, a sputtering gas is introduced from the gas introduction portion 30 b toward the film formation chamber 321. A DC voltage is applied from the power source 34 to the target 33a to plasmatize the sputtering gas. The ions generated from the plasma impinge on the target 33a, and particles of the film-forming material passing through the impinged target 33a fly out, and are deposited on the wafer W placed on the platform 31. Thereby, a thin film is formed on the wafer W.

When the film formation is completed, the application of voltage to the electrodes inside the electrostatic chuck 31b is stopped, and the adsorption and fixing of the wafer W by the electrostatic chuck 31b is released. The lift mechanism 32 raises the pin 32c, and lifts the wafer W from the stage 31. The pin 32c is raised to the receiving position. The vacuum gate valve 321 a of the film forming chamber 321 is opened, and the transfer arm 311 of the vacuum transfer chamber 310 is entered into the chamber 30.

The wafer W is held by the transfer arm 311 and is carried out from the chamber 30. When the wafer W is carried out, the vacuum gate valve 321a of the film formation chamber 321 is closed. Then, the vacuum gate valve 322 a of the film formation chamber 322 adjacent to the film formation chamber 321 is opened, and the wafer W is carried into the chamber 30. In this manner, the wafer W is sequentially carried into a plurality of film forming chambers 321 to 325 and necessary film forming processing is performed.

[Effects] (1) As described above, the film forming apparatus 100 according to this embodiment includes the first setting unit 42 that sets the first area S1 of a predetermined size, and the second setting unit 43 that is set larger than the first area S1. The second area S2 that includes all the first area S1; the detection unit 44 detects the image of the reflected light of the wafer W that is housed in the holder H and has been captured and corresponds to the first area S1 and the second area S2 The value of the area of the area where the inter-area overlaps; and the determination unit 45 determines whether the position of the wafer W with respect to the holder H is abnormal based on whether the value detected by the detection unit 44 exceeds a threshold value.

In this way, by using the captured image W of the reflected light of the wafer W, it is possible to detect abnormality in the position of the wafer W having different surface properties by a common detection means. Furthermore, the area of the detection area D, which is an area that overlaps with the area between the first area S1 and the second area S2, changes in accordance with the overshoot of the wafer W. Therefore, there is no need for a center point, etc. A warped or twisted wafer W can also accurately determine an abnormal position.

(2) The size of the first area S1 is a size including the image Sw of the reflected light from the wafer W accommodated in the holder H at a normal position. Therefore, it is easy to determine the degree of overshoot from the exposure amount of the first region S1.

(3) The first region S1 and the second region S2 are concentric circles. In this way, since the distance between the concentric circles is consistent in the 360 ° direction, the abnormality is determined based on the overlapping area between the concentric circles, and the determination can be made regardless of the direction in which the wafer W is punched in the holder H.

(4) having an input section 48 that instructs the setting of the first area S1 using the first setting section 42, and the second setting section 43 corresponds to the setting of the first area S1 using the input section 48, The second area S2 is set. If the first area S1 is set in accordance with an instruction from the input unit 48, the second area S2 is also set. Therefore, when processing a wafer W of a different size, the first area S1 and the second area can be easily performed. Changes to S2.

(5) A display unit 49 is provided, which displays information on the area of the area overlapping the image Sw of the reflected light corresponding to the area between the first area S1 and the second area S2. Therefore, the operator can visually recognize the degree of overshoot of the wafer W.

The display unit 49 displays abnormal information. Therefore, the operator can visually recognize the abnormality in the position of the wafer W, and can respond in advance.

(7) A single light source 22 that irradiates light to the wafer W, and a camera 21 that captures reflected light from the wafer W. Accordingly, halation caused by the plurality of light sources 22 is suppressed, and an accurate image of the wafer W can be captured. Therefore, an abnormality in the position of the wafer W can be accurately determined with a simple structure.

[Other Embodiments] (1) The present invention is not limited to the embodiment itself, and the constituent elements can be appropriately modified without departing from the spirit thereof. In addition, a plurality of constituent elements disclosed in the embodiments may be appropriately combined. For example, several constituent elements may be removed from the constituent elements shown in the above-mentioned embodiments, or constituent elements related to different embodiments may be appropriately combined.

(2) The size of the accommodating portion Hs of the holder H is only required to accommodate the wafer W. However, when the holder H is lifted from the stage 31 by the pin 32c after the film formation, the wafer W may jump. This is considered to be caused by, for example, the residual electrostatic force of the electrostatic chuck 31b. At this time, if the depth of the accommodating portion Hs is shallow, it may be punched up to the extent that it is exposed from the holder H. Therefore, a certain depth dp is required in the accommodating portion Hs (see FIG. 14). On the other hand, if the depth dp of the accommodating portion Hs is set to be large, the holder H shields the film-forming material ejected from the target during film formation, and the film thickness on the outer periphery of the wafer W becomes larger than that of the center of the wafer W The film thickness is thin. As a result of intensive studies, the inventors found that it is preferably set to 1.8 mm ≦ dp ≦ 2.1 mm. Thereby, uniformity of film formation can be achieved, and overshoot of the degree of exposure after film formation can be prevented.

The workpiece of the film formation object is not limited to the semiconductor wafer W. For example, it can be applied to various workpieces for film formation such as digital video discs (DVD) and hard disks, mirrors, display panels, and solar cell panels. . The shape of the workpiece is not limited to a circle, and may be a polygon such as a square, or a three-dimensional object. For example, it may be a polyhedron formed by a plurality of planes, such as a cube, a cuboid, a curved body including one or more curved surfaces such as a hemispherical shape, a dome shape, a bowl shape, and the like, a rectangular tube shape, a cylindrical shape, and a conical shape A complex consisting of surfaces and planes. In addition, on the surface on the opposite side of the surface on which the film W is formed, that is, on the surface on which the circuit is formed, a protective adhesive tape may be attached before film formation.

(4) The first region S1 and the second region S2 are not limited to a circle. Depending on the shape of the workpiece, it may be polygonal. In addition, the size of the first region S1 does not necessarily need to be larger than the workpiece, and may be smaller than the workpiece. The shape of the holder H may be a shape that matches the shape of these workpieces. The holder H is only required to be a member on which a workpiece is placed and carried, and the name of a tray, a susceptor, or the like is not limited.

(5) The reflected light from the workpiece may be light reflected from external lighting or natural light. That is, in order to obtain reflected light from the workpiece, there is no limitation on which light source is used. In addition, the light source may be in a form in which light is guided by an optical fiber to irradiate the workpiece.

(6) The specific structure of the film formation part 300 is not limited to the said form. It may be an in-line film forming apparatus. A heater may be provided on the platform 31 for pre-heating. The mechanism holding the holder H may be a mechanical chuck mechanism. In addition, a dedicated chamber 30 for pre-heating may be provided. For example, a pre-processing chamber may be provided between the workpiece access chamber 326 and the film forming chamber 321, and pre-heating may be performed in the pre-processing chamber. In addition, it is also possible to perform the pre-processing in the pre-processing chamber by using the work access chamber 326 as a dual-purpose system.

100‧‧‧film forming device

200‧‧‧ Atmospheric Loader

210‧‧‧Fixer Supply Department

220‧‧‧ Wafer Supply Department

230‧‧‧testing agency

231‧‧‧Support

231a‧‧‧open

232‧‧‧Elevating plate

233‧‧‧ Lifting shaft

234‧‧‧ Pillar

235‧‧‧ Camera Department

21‧‧‧ Camera

22‧‧‧light source

300‧‧‧Film forming department

310‧‧‧vacuum transfer room

311‧‧‧carrying arm

321 ～ 325‧‧‧film forming room

321a ～ 325a‧‧‧Vacuum gate valve

326‧‧‧Workpiece access room

326a‧‧‧vacuum gate valve

326b‧‧‧Air gate valve

30‧‧‧ chamber

30a‧‧‧Pressure gauge

30b‧‧‧Gas introduction department

31‧‧‧platform

31a‧‧‧axis

31b‧‧‧ electrostatic chuck

32‧‧‧Lifting mechanism

32a‧‧‧

32b‧‧‧units

32c‧‧‧pin

33‧‧‧Sputtering Source

33a‧‧‧target

33b‧‧‧Back

33c‧‧‧Conductive member

34‧‧‧ Power

400‧‧‧control device

40‧‧‧Institutional Control Department

41‧‧‧Display Processing Department

42‧‧‧The first setting section

43‧‧‧ 2nd setting section

44‧‧‧Testing Department

45‧‧‧Judgment Department

46‧‧‧Memory Department

47‧‧‧I / O Control Department

48‧‧‧Input Department

49‧‧‧Display

a, b, c, p ‧‧‧ impulse

D‧‧‧ Detection area

dp‧‧‧ depth

EB1, EB2, EB3‧‧‧ error bars

H‧‧‧ retainer

Ho‧‧‧ opening

Hs‧‧‧ Containment Department

Sw‧‧‧ reflected light image

S1‧‧‧Area 1

S2‧‧‧Zone 2

Th1, Th2‧‧‧threshold

W‧‧‧ Wafer

α, β, γ‧‧‧ diameter

101 ～ 112‧‧‧step

1 (A) and 1 (B) are a plan view and a side view schematically showing a wafer having warpage. 2 (A) and 2 (B) are a plan view and a cross-sectional view taken along the arrow A-A of the holder for accommodating a wafer. 3 is a plan view schematically showing a configuration of a film forming apparatus according to the embodiment. Fig. 4 is a cross-sectional view taken along the line B-B in Fig. 3, which schematically illustrates the structure of a detection mechanism. FIG. 5 is a cross-sectional view showing a wafer receiving state of the detection mechanism of FIG. 4. FIG. 6 is a cross-sectional view showing a wafer mounting state of the detection mechanism of FIG. 4. FIG. 7 is a bottom view showing a camera and a light source of the imaging unit. 8 (A) and 8 (B) are explanatory diagrams showing examples of images of reflected light, display screens of the first region, and the second region. FIG. 9 is a cross-sectional view schematically showing the structure of a film forming chamber. FIG. 10 is a cross-sectional view showing a state in which the holder of the film forming chamber of FIG. 9 is placed. FIG. 11 is a block diagram showing a control device. FIG. 12 is an explanatory diagram showing an image of the reflected light, and the sizes of the first region and the second region. 13 (A) to (F) are explanatory diagrams showing the form of the position of the wafer with respect to the holder. FIG. 14 is an explanatory diagram showing a form of a punch up of a wafer with respect to a holder. FIG. 15 is a graph showing the relationship between the overshoot and the detected value. FIG. 16 is a flowchart showing a processing routine of the embodiment.

Claims (10)

A workpiece detection device includes a first setting unit that sets a first area of a predetermined size, and a second setting unit that sets a second area that is larger than the first area and includes all the first areas. Area; an imaging unit that captures a workpiece housed in the holder and detects reflected light reflected from the workpiece by light radiated from the light source; a detection unit that detects an image of the reflected light formed by the detected reflected light corresponding to A value of an area of a region overlapping the region between the first region and the second region; and a determination unit that determines whether the value detected by the detection unit exceeds a threshold value with respect to the fixed Is there any abnormality in the position of the workpiece of the device? The workpiece detection device according to item 1 of the scope of patent application, wherein the size of the first region is a size that incorporates an image of reflected light from a workpiece located in a normal position in the holder. The workpiece inspection device according to item 1 of the scope of patent application, wherein the first region and the second region are concentric circles. The workpiece inspection device according to item 2 of the scope of patent application, wherein the first region and the second region are concentric circles. The workpiece detection device according to any one of claims 1 to 4, including an input section, which instructs setting of the first area using the first setting section, and the first The 2 setting unit sets the second region corresponding to the setting of the first region using the input unit. The workpiece detection device according to any one of claims 1 to 4 of the scope of patent application, which includes a display section that displays information corresponding to the area. The workpiece detection device according to item 6 of the patent application scope, wherein the display section displays information of the abnormality. The workpiece detection device according to any one of claims 1 to 4, wherein the light source is a single light source that irradiates light to the workpiece. A film forming apparatus, comprising: the workpiece detecting device according to any one of the first to eighth aspects of the patent scope; and a film forming section for a position abnormality that has been determined by the workpiece detecting device. The workpiece is formed into a film. A workpiece detection method, wherein a first setting process sets a first region of a predetermined size; a second setting process sets a second region that is larger than the first region and includes all of the first region Detection processing, which photographs a workpiece housed in the holder, detects reflected light reflected from the workpiece by light radiated from the light source, and detects an image of the reflected light formed by the detected reflected light corresponding to and A value of the area of an area where the area between the first area and the second area overlaps; and a determination process for determining the workpiece with respect to the fixture based on whether or not the value detected by the detection process exceeds a threshold value. Is there any abnormality in the position?