JP2019105532A - Workpiece detection apparatus, film formation apparatus, and workpiece detection method - Google Patents

Abstract

To provide a workpiece detection apparatus, a film formation apparatus, and a workpiece detection method, capable of detecting an abnormality in a workpiece position having a warp or the like without depending on surface properties of the workpiece by common detection means.SOLUTION: The workpiece detection apparatus includes: a first setting unit for setting a first area S1 of a predetermined size; a second setting unit for setting a second area S2 which is larger than the first area S1 and in which all the first area S1 can be accommodated; a detection unit for detecting a value corresponding to an area of an area where an image Sw of reflected light from a wafer contained in a holder and imaged overlaps an area between the first area S1 and the second area S2; and a determination unit for determining presence or absence of an abnormality in a position of the wafer relative to the holder based on whether the value detected by the detection unit exceeds a threshold value.SELECTED DRAWING: Figure 8

Description

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

  In the manufacturing process of various semiconductor devices, a plurality of films may be stacked and formed on a workpiece such as a wafer or a glass substrate. As a film forming apparatus for forming a plurality of films, there is a so-called multi-chamber type film forming apparatus provided with a plurality of depressurizable chambers. A target made of a film forming material is disposed in each chamber. An inert gas is introduced into the chamber, a voltage is applied to the target to plasmatize the inert gas to generate ions, and the ions collide with the target. Film formation is performed by sputtering in which particles of material ejected from a target are deposited on a workpiece.

JP 2008-244078 A

  A workpiece on which film formation is performed by sputtering is carried to a film forming apparatus while being placed in a holder. The position and inclination of the work placed on the holder may not be constant, and the work may be out of the holder. In a workpiece having a large degree of protrusion from the holder, the distance between the target and the plasma is not constant in the film formation surface, and uniform film formation processing can not be performed.

  In order to cope with this, a method is conceivable in which the position such as the outer periphery of the work is detected by a laser sensor or the like and the position abnormality is determined from the amount of deviation from the reference position. However, the surface quality of the work differs depending on the material. For example, semiconductor wafers differ in light transmittance or reflectance depending on whether the material is silicon (Si) or silicon carbide (SiC), whether a pattern is formed, film formation is performed, etc. . When multiple types of wafers with different surface textures are to be detected by a common sensor, for example, the values such as the sensitivity optimum for detecting each wafer are different, so the values are changed each time the wafers are changed. There must be. In addition, it may be difficult to know the value of sensitivity etc. optimum for detecting each wafer. In order to cope with this, it is not practical to provide a sensor suitable for each wafer having different surface textures, which is expensive and impractical.

  Therefore, the camera picks up an arbitrary image captured on the wafer, finds the center position of the picked up image of the arbitrary image, and calculates the displacement of the workpiece from this center position and the center position as a preset reference. A method of detecting an abnormality in position is conceivable (see Patent Document 1).

  However, there are very thin wafers. For example, in the power device field, a wafer is formed in advance by forming an electronic circuit such as a MOS-FET and then processed very thinly by scraping the back surface, and then transferred to a film forming apparatus and aluminum (Al (Al) ) Is deposited. Such a thin wafer is warped or distorted. The mode of the warping or distortion is different for each wafer, so the center position is not constant even if it is a wafer of the same diameter or a wafer at the correct position. Therefore, it is not only easy to set the center position of the wafer as a reference, but also it is difficult to determine the amount of deviation based on the set center position.

  An object of the present invention is to provide a workpiece detection apparatus, a film formation apparatus, and a workpiece detection method capable of detecting an abnormality in the position of a workpiece having a warp or the like without depending on the surface texture of the workpiece by common detection means. Do.

  In order to achieve the above object, a work detection apparatus according to the present invention includes a first setting unit for setting a first area of a predetermined size, and a first area larger than the first area. A second setting unit for setting a second region in which all the light is contained, and an image of light reflected from the work received by being captured by the holder, a region between the first region and the second region And a detection unit that detects a value corresponding to the area of the overlapping region, and whether there is an abnormality in the position of the work relative to the holder based on whether the value detected by the detection unit exceeds a threshold value. And a determination unit.

  The first area may be sized to receive an image of light reflected from a workpiece at a normal position housed in a holder. The first area and the second area may be concentric circles.

  An input unit for instructing setting of the first area by the first setting unit, and the second setting unit set the second area according to the setting of the first area by the input unit You may

  You may have a display part which displays the information corresponding to the said area. The display unit may display information indicating the abnormality.

  You may have a single light source which irradiates light to the said workpiece | work, and the imaging part which images the reflected light from the said workpiece | work.

  Further, the film forming apparatus of the present invention includes the workpiece detecting device, and a film forming unit for forming a film on a workpiece whose presence or absence in position is determined by the workpiece detecting device.

  Further, according to the work detection method of the present invention, a first setting process in which a computer or an electronic circuit sets a first area of a predetermined size, and the first area being larger than the first area A second setting process for setting a second area which is completely contained, and a value corresponding to an area in which an image of light reflected from the workpiece overlaps an area between the first area and the second area A detection process to be detected and a determination process to determine the presence or absence of an abnormality of the position of the work relative to the holder based on whether the value detected by the detection unit exceeds a threshold value are executed.

  According to the present invention, it is possible to detect an abnormality in the position of a workpiece having a warp or the like without depending on the surface property by the common detection means.

It is the top view (A) and side view (B) which show the wafer with curvature typically. It is a top view (A) which shows the holder which accommodates a wafer, and an AA arrow sectional drawing (B). It is a top view which shows typically the structure of the film-forming apparatus which concerns on embodiment. It is a BB arrow directional cross-sectional view of FIG. 3 which shows the structure of a detection mechanism typically. FIG. 5 is a cross-sectional view showing a wafer receiving state of the detection mechanism of FIG. 4; It is sectional drawing which shows the wafer mounting state of the detection mechanism of FIG. It is a bottom view which shows the camera and light source of an imaging part. It is explanatory drawing which shows the example of a display screen of the image of reflected light, a 1st area | region, and a 2nd area | region. It is sectional drawing which shows the structure of the film-forming chamber typically. It is sectional drawing which shows the holder mounting state of the film-forming chamber of FIG. It is a block diagram showing a control device. It is an explanatory view showing a size of a picture of catoptric light, the 1st field, and the 2nd field. It is explanatory drawing which shows the aspect of the position of the wafer with respect to a holder. It is explanatory drawing which shows the aspect of the mounting of the wafer with respect to a holder. It is a graph which shows the relationship between a riding amount and a detected value. It is a flowchart which shows the process sequence of embodiment.

Embodiments of the present invention will be specifically described with reference to the drawings.
(Wafer)
In the present embodiment, an example of using a semiconductor wafer W as shown in FIG. 1 as a workpiece to be film-formed will be described. In the wafer W, a circuit is formed on the front surface before the film forming process, and the back surface is ground. In recent years, the wafer W is ground to a thickness of several tens of μm due to a thinning tendency accompanying high integration. As described above, since the wafer W is formed so thin, warpage and distortion occur. In the film forming step, a film is formed on the ground surface.

(holder)
Further, in the present embodiment, a holder H is used as a member on which the wafer W to be film-formed is placed, as shown in FIG. The holder H is a bottomed cylindrical member having a rectangular cross section cut along the A-A cut surface, and has an accommodating portion Hs having a size for accommodating the wafer W therein. At the bottom of the holder H, an opening Ho having a diameter smaller than that of the wafer W is formed. Therefore, the outer periphery of the surface of the wafer W can be supported by the bottom of the periphery of the opening Ho. Further, the opening Ho has a size that allows the lift plate 232 and the lift shaft 233 to be inserted and removed (see FIG. 5).

(Deposition apparatus)
(Overview)
As shown in FIG. 3, the film forming apparatus 100 according to the present embodiment includes an atmospheric loader 200, a film forming unit 300, and a control device 400.

  The atmosphere loader 200 is a component that places the wafer W on the holder H and carries the wafer W into the film forming unit 300. The film forming unit 300 is a component that performs film formation by sputtering on the wafer W placed on the holder H. The control device 400 is a device that controls each part of the film forming apparatus 100. Hereinafter, the details of each part of the film forming apparatus 100 will be described.

(Atmospheric loader)
The atmosphere 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 has a holder cassette in which a large number of holders H are stacked and accommodated, and a transfer arm. The wafer supply unit 220 has a wafer cassette in which a large number of wafers W are stacked and accommodated, and a transfer arm. The detection mechanism 230 is a component that captures an image of the wafer W placed on the holder H.

  The holder H taken out of the holder cassette of the holder supply unit 210 by the transport arm is set in the detection mechanism 230. The wafer W taken out of the wafer cassette of the wafer supply unit 220 is placed on the storage unit Hs of the holder H set in the detection mechanism 230. The wafer W is carried into the film forming unit 300 while being mounted on the holder H by a transfer arm (not shown).

  As shown in FIG. 4, the detection mechanism 230 includes a support 231, an elevating plate 232, an elevating shaft 233, a support 234, and an imaging unit 235. The support stand 231 is a stand on which the holder H is placed. The support 231 is provided with an opening 231 a corresponding to the opening Ho of the holder H. The raising and lowering plate 232 is a plate-like body which can be advanced and retracted in the vertical direction from the lower side of the support base 231 through the opening 231 a and the opening Ho.

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

  As shown in FIG. 5, the elevating plate 232 which has advanced from the opening 231a of the support 231 and the opening Ho of the holder H by the elevating shaft 233 and receives the wafer W coming above the holder H. Then, as shown in FIG. 6, the elevating plate 232 is lowered, and the wafer W is accommodated in the accommodating portion Hs of the holder H. The pillars 234 are attached to two pillar-shaped members erected from both sides of the support base 231 in a direction parallel to the diameter of the holder H and arranged so as to straddle the upper side of the support base 231 Member.

  The imaging unit 235 includes a camera 21 and a light source 22. As shown in FIG. 7, the camera 21 has an optical member such as a lens and an image sensor which is a light receiving element such as a CMOS or CCD, and outputs a signal corresponding to the light detected by the light receiving element through the optical member. It is an imaging device. The light source 22 is an illumination device such as an LED that emits light to the wafer W. In the present 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 illuminate the entire wafer W, but it is not necessary to illuminate the entire wafer W. For example, in the present embodiment, the wafer W is irradiated with light having a diameter of about 10 mm.

  The image of the reflected light from the wafer W taken by the camera 21 is displayed on the screen of the display unit 49 described later, as shown in FIG. The image of the light reflected from the wafer W means an outline corresponding to the outer edge of the reflected light or the wafer W in the image formed by detecting the light irradiated to the wafer W from the light source 22 and reflected by the light receiving element. It is an area surrounded by Hereinafter, the image of the reflected light from the wafer W is referred to as an image Sw of the reflected light. The contour corresponding to the outer edge of the reflected light can be imaged at a brightness distinguishable from the background, regardless of the total reflection, transparent, and semitransparent wafer W. For this reason, the area | region of the light quantity more than the threshold value preset can be extracted as an image Sw of reflected light.

(Deposition unit)
As shown in FIG. 3, the film forming unit 300 has a multi-chamber configuration in which a plurality of chambers 30 are disposed along the side surfaces of the vacuum transfer chamber 310 with the hexagonal transfer chamber 310 as a center. . At least one of the plurality of chambers 30 is a film forming chamber for forming a film on the wafer W. The number of film forming chambers is determined according to the number of films formed on the wafer W, and is not limited to a specific number. In addition, any of the chambers 30 may be a cooling chamber, a heating chamber, an etching chamber, or a chamber for performing processing other than film formation.

  In the present embodiment, the chamber 30 is, for example, five film forming chambers 321 to 325 and one load lock chamber 326 as an example. The shape of the vacuum transfer chamber 310 is not limited to a hexagonal column, and may be a polygonal shape or a cylindrical shape according to the number of film forming chambers 321 to 325 required.

  The load lock chamber 326 is a chamber for carrying in the holder H from the atmospheric loader 200 from the outside and carrying the holder H for which the film forming process is finished out to the atmospheric loader 200. One side of the load lock chamber 326 is connected to the vacuum transfer chamber 310 via the vacuum gate valve 326a, and the other side is connected to the atmospheric loader 200 via the atmospheric gate valve 326b. By opening and closing the vacuum gate valve 326a, communication and shutoff can be switched between the vacuum transfer chamber 310 and the vacuum transfer chamber 310. By opening and closing the atmosphere gate valve 326b, it is possible to switch the communication between the air loader 200 and the shutoff.

  Inside the load lock chamber 326, a holder (not shown) for holding the loaded wafer W is provided. Further, the load lock chamber 326 is provided with an exhaust device and a pressure gauge (not shown), and can be depressurized to a desired pressure.

  The vacuum transfer chamber 310 is a chamber for carrying the wafer W carried into the load lock chamber 326 into and out of the respective film forming chambers 321 to 325. Further, the vacuum transfer chamber 310 is provided with an exhaust device and a pressure gauge (not shown), and can be depressurized to a desired pressure.

  At the center of the vacuum transfer chamber 310, a transfer arm 311 is provided to transfer the wafer W. The transfer arm 311 extends into the load lock chamber 326 and the film forming chambers 321 to 325, takes out the wafer W from each chamber, carries it into the vacuum transfer chamber 310, and carries it into another chamber.

  The plurality of film forming chambers 321 to 325 open the respective vacuum gate valves 321 a to 325 a at the time of loading and unloading. At the time of processing, the vacuum gate valves 321a to 325a are closed to seal the inside of each chamber. In each of the film forming chambers 321 to 325, film formation is performed on the wafer W. Each of the film forming chambers 321 to 325 may be configured similarly or may be configured differently.

  Here, the structure of the film forming chamber 321 will be described with reference to FIGS. 9 and 10 as an example. The film forming chamber 321 includes a chamber 30, a stage 31, an elevating mechanism 32, and a sputtering source 33. The chamber 30 is a container capable of evacuating the inside. The chamber 30 is provided with a pressure gauge 30a and an exhaust device (not shown). The inside of the chamber 30 is constantly evacuated by the exhaust device and managed to be in a predetermined depressurized state. Further, a gas introducing unit 30 b is provided in the chamber 30. Sputtering gas can be introduced into the chamber 30 from the gas introduction unit 30 b. For example, an inert gas such as argon can be used as the sputtering gas.

  The stage 31 is a member disposed near the inner bottom of the chamber 30 and on which the holder H accommodating the wafer W is placed. The stage 31 has a disk shape, and is supported by being connected to a shaft 31 a extending from the bottom of the chamber 30. The shaft 31 a airtightly penetrates the bottom of the chamber 30 and communicates with the outside.

  The stage 31 has a convex cross section as a result of the central portion projecting. The upper surface of the central portion becomes a flat mounting surface on which the wafer W is mounted by entering from the opening Ho of the holder H. The mounting surface constitutes an electrostatic chuck 31 b. The electrostatic chuck 31 b is composed of a metal base member and a ceramic dielectric. The mounting surface of the wafer W is the top surface of the dielectric.

  An electrode is provided inside the dielectric, and 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 an upper surface of the dielectric. It is fixed by suction. A cable is passed through the inside of the shaft 31 a of the stage 31 and connected to a power supply (not shown) provided outside the chamber 30 in order to supply power to the electrode inside the dielectric. The stage 31 is provided with a cooling mechanism (not shown), and is provided so as to be able to cool the stage 31 by the cooling mechanism.

  The lift mechanism 32 is provided near the bottom of the chamber 30. The lifting mechanism 32 has a rod 32a, a table 32b, and a pin 32c. The rod 32a airtightly penetrates the bottom of the chamber 30, and is connected to a drive mechanism (not shown) such as a cylinder device or a motor outside the chamber 30. By driving the drive mechanism, the rod 32 a moves up and down inside the chamber 30.

  The table 32b is attached to the upper end of the rod 32a. The table 32 b has, for example, a disk shape, and is disposed below the stage 31 and substantially in parallel with the stage 31. A through hole is formed at the center of the table 32b. The shaft 31 a of the stage 31 is inserted through the through hole. The table 32b moves up and down relative to the stage 31 and the shaft 31a by raising and lowering the rod 32a.

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

  As shown in FIG. 9, the pins 32c receive and hold the holder H carried in from the vacuum transfer chamber 310 by the transfer arm 311 ascending as shown in FIG. 9, and as shown in FIG. The wafer W placed on top of the stage 31 is transported to the electrostatic chuck 31 b which is the upper surface of the stage 31. Therefore, the pin 32c is set to ascend to at least a receiving position for receiving the holder H from the transfer arm 311. Further, the upper end of the pin 32 c is set to descend to at least the same position as the upper surface of the guide hole of the stage 31. The upper surface of the stage 31 is a film formation position where film formation is performed on the wafer W.

  The sputtering source 33 is a supply source of film forming material which is deposited on the wafer W to be a film. The sputter source 33 is disposed at the top of the chamber 30. The sputtering source 33 is composed of a target 33a, a backing plate 33b and a conductive member 33c.

  The target 33 a is attached to, for example, the upper surface of the chamber 30, and the surface of the target 33 a is disposed to face the stage 31 installed near the bottom of the chamber 30. The target 33a is made of a film forming material, and any known film forming material can be applied. 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 a long cylinder shape and a prism shape, may be used.

  The backing plate 33 b is a member that holds the opposite surface of the target 33 a to the stage 31. The conductive member 33 c is a member that applies power to the target 33 a from the outside of the chamber 30 via the backing plate 33 b. The sputtering source 33 is provided with a magnet, a cooling mechanism, and the like as needed.

  A power source 34 is connected to the sputtering source 33. The power supply 34 applies power to the target 33 a to plasmify the sputtering gas introduced around the target 33 a. The power supply 34 in the present embodiment is, for example, a DC power supply that applies a high voltage. In addition, in the case of the apparatus which performs high frequency sputter | spatter, it can also be set as RF power supply.

  A sputtering gas is introduced into the chamber 30, and a DC voltage is applied from the power supply 34 to the target 33a. The application of the DC voltage turns the sputtering gas into plasma, generating ions. When the generated ions collide with the target 33a, the material of the target 33a jumps out as particles. By depositing the ejected particles on the wafer W placed on the stage 31, a thin film is formed on the wafer W.

  The control device 400 is a device that controls the air loader 200 and the film forming unit 300 described above. The control device 400 can be configured, for example, by a dedicated electronic circuit or a computer operating with a predetermined program. The control content of each part is programmed in the control device 400, and executed by a processing device such as a PLC or a CPU. This makes it possible to cope with a wide variety of film formation 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 unit 40, a display processing unit 41, a first setting unit 42, a second setting unit 43, a detection unit 44, a determination unit 45, a storage unit 46, and an input / output control unit 47. .

  The mechanism control unit 40 is a processing unit that controls the mechanism of each unit. As a mechanism to be controlled, for example, a holder supply unit 210, a wafer supply unit 220 and a transfer arm (not shown), a drive source of an elevation shaft 233 of the detection mechanism 230, a camera 21 of the imaging unit 235, a light source 22, a vacuum gate valve 321a 325 325a, 326a and atmosphere gate valve 326b, vacuum transfer chamber 310, film forming chamber 321 to 325 and exhaust device of load lock chamber 326, transfer arm 311 of vacuum transfer chamber 310, gas introducing portion 30b of film forming chamber 321 to 325 , Power supply 34, and lifting mechanism 32.

  The display processing unit 41 performs display processing of the 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. Further, the display processing unit 41 controls the display of a first area S1, a second area S2, and a detection area D which will be described later.

  As shown in FIG. 8A, the first setting unit 42 sets a first area S1 of a predetermined size. The predetermined size is a size in which the image Sw of the reflected light is accommodated in the present embodiment. Further, in the present embodiment, the first region S1 is circular. The size of the image Sw of the reflected light may be equal to or larger than the size of the image Sw of the reflected light, and as shown in FIG. 8B, the wafer W is in a state of being run over in the storage section Hs. Due to the deviation of the hit position, the image Sw of the actually captured reflected light may deviate from the first region S1. However, each time the first setting unit 42 changes the target wafer W to a wafer W on which different materials or patterns are formed, the first setting unit 42 is positioned at a position where reflected light from the wafer W at the normal position is contained. An area S1 of 1 is set. Here, “on the top” refers to a state in which the wafer W is inclined because a part of the outer periphery of the wafer W contacts the side surface of the housing portion Hs or the upper surface of the holder H. For example, the state shown in FIG. 13B (B), (D), (E) and (F) is called a state in which the vehicle rides on. The state of running on in the accommodation unit Hs refers to a state such as (B) and (D).

  Further, depending on the state of warpage of the wafer W, the amount of positional deviation of the image Sw of the reflected light caused by the reflection of light, that is, the offset may increase, so in consideration of this, the first region S1 is a wafer It is preferable to set larger than W.

  The second setting unit 43 sets a second area S2 which is larger than the first area S1 and in which all the first areas S1 can be contained. In the present embodiment, the second area S2 is a concentric circle having a diameter larger than that of the first area S1. Therefore, as shown in FIG. 12, assuming that 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, then α ≦ β <γ.

  The detection unit 44 detects a value corresponding to the area of the area where the image Sw of the reflected light overlaps the area between the first area S1 and the second area S2. The area thus detected is called a detection area D. That is, the detection unit 44 extracts the area of the light amount equal to or larger than the preset threshold value as the image Sw of the reflected light, and the extracted image Sw of the reflected light, the first area S1, and the second area S2. A region overlapping with the region between them is referred to as a detection region D. The value corresponding to the area of the detection area D can be obtained, for example, by 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 is 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 based on the number of pixels. The value of the area may be an area value on the screen or an actual area value calculated based on the number of pixels and the scale of the imaging region.

  Determination unit 45 determines the presence or absence of an abnormality in the position of wafer W with respect to holder H based on whether the value detected by detection unit 44 exceeds a threshold value. The area of the detection area D is different depending on the amount of run-up of the wafer W. Due to the difference in the type of wafer W, for example, the surface property, the area of the detection area D shown in the case where a deviation occurs varies. For this reason, the threshold for identifying whether the area is normal or abnormal is different from the area of the detection area D.

  For example, as shown in FIG. 13, (A) to (D) show cases where the wafer W does not protrude from the storage section Hs, and (E) to (F) show that the wafer W protrudes from the storage section Hs. Is the case. (A), (B) and (E) are cases where the wafer W has a convex warpage downward, and (C), (D) and (F) mean that the wafer W has a convex warpage upward. It is the case of having. In the present embodiment, in the case of (A) to (D), OK, ie, it is accepted as normal, and in the case of (E) and (F), it is accepted as NG, ie, not abnormal.

  If the wafer W is transported to the stage 31 in the states of (E) and (F) of FIG. 13, the wafer W may not be attracted by the electrostatic chuck 31 b. In addition, since the wafer W is mounted in a position shifted from the normal position of the stage 31 even if it can be absorbed, the portion of the wafer W not in contact with the stage 31 is not cooled sufficiently from the stage 31 and heated. It will In addition, a film to be formed may adhere to the upper surface of the stage 31 on which the wafer W is not mounted.

  However, as shown in FIG. 14, even if the run-up 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. This is because the light reflectance and the like differ depending on the surface properties of the wafer W, so the outline may become clear or may be blurred, and the size of the image Sw of the reflected light to be captured is not constant. For example, the relationship between the amount of run-up of the wafer W and the value detected by the detection unit 44 is shown in FIG. The circle, square and triangle markers in FIG. 15 indicate wafers W having different surface textures.

  For each wafer W, a detection value, which is a value detected by the detection unit 44, is determined as follows. The wafer W is placed on the holder H with a predetermined amount of run-up, and set on the support 231 of the detection mechanism 230. Then, the holder H is rotated by 30 degrees each time by 360 degrees to pick up an image Sw of the reflected light at 12 points. A detection value which is a value corresponding to the area of the detection area D is determined from the image Sw of the reflected light that has been picked up.

  The detection value of each wafer W indicates the upper limit value of the detection value of each wafer W with each marker in the run-up amounts a and b. The lower limit value of the detection value of each wafer W is indicated by each marker for the amount of run-up c. The distribution of detected values on the same wafer W is indicated by an error bar. When the error bars of the wafers W are shown, they overlap with each other. Therefore, in FIG. 15, the distribution of all detection values in a certain amount of run is shown as an error bar. These error bars are called error bars EB1, EB2, and EB3.

  The detected value of each wafer W indicated by the marker becomes a different value even for the same amount of run when compared for each of the amounts of run a, b and c. It is considered that this is because the surface properties are different. Further, there is a variation in the detected values of the same wafer W. It is considered that this is because the wafer W is warped.

  For example, in the case where it is determined that an overhang is out of the holder H when it is the run-up amount c or more, that is, it is abnormal, the detected value of the error bar EB2 is a value larger than the upper limit value (circle value) Among the detected values of the error bar EB3, a value smaller than the lower limit value (square value) is set as the threshold value Th1.

  If a value larger than the value of the upper limit of the error bar EB2 is set as the threshold value Th1, if the detected value is equal to or less than Th1, the wafer W is treated as being accommodated in the accommodation unit Hs. Thereby, although it does not protrude from the holder H, it can be judged as abnormal and the fall of productivity by performing stop processing frequently can be prevented. Further, when the value smaller than the lower limit value among the detected values of the error bar EB3 is set as the threshold value Th1, the possibility that the wafer W protruding from the holder H is carried into the film forming unit 300 is reduced. Safety is ensured because it can be 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.

  If 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 square marker value may be set as the threshold value Th2. In this case, although it is judged as abnormal although it does not protrude from the holder H and the stop processing occurs, the safety is secured.

  The storage unit 46 is a configuration unit that stores information necessary for the control of the present embodiment. This information is set by the imaging timing of the camera 21 of the imaging unit 235, the light amount of the light source 22, the setting condition of the first area S1 set by the first setting unit 42, and the second setting unit 43 The setting condition of the area S2, the detection value by the detection unit 44, the threshold value of the determination by the determination unit 45, and the determination result are included. The setting condition of the second area S2 includes the difference value between the diameter of the first area S1 and the diameter of the second area S2. The mechanism control unit 40 generates and outputs control signals to the respective units based on the information stored in the storage unit 46.

  The storage unit 46 can be configured by, 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 VRAM or the like for image display can also be regarded as the storage unit 46. The input / output control unit 47 is an interface that controls signal conversion and input / output with each unit to be controlled.

  Further, 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, or a mouse for the operator to operate the film forming apparatus 100 via the control device 400. The instruction to set the first area S1 by the first setting unit 42, the difference value of the diameter of the second area S2 with respect to the diameter of the first area S1, the threshold value of the determination of the determination unit 45, etc. You can enter from 48. The second setting unit 43 sets the second area S2 based on the setting instruction of the first area S1 from the input unit 48 and the setting condition of the second area S2.

  The display unit 49 is an output device such as a display, a lamp, a meter, and the like that allows the operator to visually recognize information for checking the state of the device. The display displays information indicating 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, a numerical value of the area of the detection area D, or both of them.

  For example, as shown in FIG. 8A, when the operator designates an arbitrary point outside the image Sw of the reflected light at the normal time displayed on the display screen by the input unit 48, the first setting is made. The unit 42 sets a first area S1 of a size that the reflected light image Sw fits in a locus passing through the designated point. Furthermore, the second setting unit 43 sets a concentric circle whose diameter is larger than the diameter of the first area S1 by the length set in the setting condition as the second area S2.

  Thus, the display of the display unit 49 displays the image Sw of the reflected light, the first area S1, and the second area S2 on the display screen. As shown in FIG. 8B, a detection region D is a region overlapping the region between the first region S1 and the second region S2 in the image Sw of the reflected light. The display also displays the determination result of the determination unit 45. For example, when it is determined that the detection area D is abnormal, the detection area D is displayed in a color-coded manner so as to be distinguished from other areas. In addition, you may provide the output device which alert | reports the above by audio | voice.

[Operation]
Next, the operation of the film forming apparatus 100 according to the present embodiment will be described. A detection method for detecting an abnormality in the position of the wafer W according to the following procedure is also an aspect of the present invention. That is, the holder H taken out of the holder supply unit 210 by the transport arm is placed on the support 231 of the detection mechanism 230 as shown in FIG. On the other hand, the wafer W taken out of 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 is raised to receive the wafer W from the transfer arm, as shown in FIG. Then, the lift plate 232 is lowered, and the wafer W is placed in the storage portion Hs of the holder H. The process of detecting the deviation of the wafer W mounted on the holder H as described above will be described with reference to the flowchart of FIG. 16 in addition to the above-described drawings.

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

  The operator looks at the image of the wafer W displayed on the display and designates the outside of the outline of the wafer W (step 103). Then, the first setting unit 42 passes a specified point and sets a circle in which the image of the wafer W is contained as the first region S1 (step 104). In addition, the second setting unit 43 sets a concentric circle in which the first area S1 is accommodated as a second area S2 (step 105). The set first area S1 and second area S2 are displayed on the display.

(Detection process)
Next, a process of detecting an abnormality in the position of the wafer W will be described based on the set first area S1 and second area S2. As described above, the light source 22 emits light to the wafer W stored in the storage portion Hs of the holder H, and the camera 21 captures an image of the reflected light (Step 106).

  The captured image Sw of the reflected light of the wafer W is displayed on the display so as to overlap the first area S1 and the second area S2 (step 107). The detection unit 44 detects a value corresponding to the area of the area where the image Sw of the reflected light captured by the camera 21 overlaps 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 (step 109). The threshold value is determined by creating a graph as shown in FIG. 15 from prior experiments. If the threshold value is exceeded (YES in step 109), the amount of deviation is large, and the amount of protrusion from the accommodating portion Hs is large, so it is determined that the state is abnormal (step 110). If it is determined that the operation is abnormal, the display displays information indicating the abnormality (step 111), and the air loader 200 and the film forming unit 300 stop their operation (step 112).

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

(Deposition processing)
Next, the film forming process for the wafer W whose position has been corrected as described above or the wafer W at the normal position will be described. First, the atmosphere gate valve 326 b is opened, and the holder H carrying the wafer W is carried into the load lock chamber 326 by the transfer arm.

  At this time, the load lock chamber 326 is at atmospheric pressure, and the vacuum gate valve 321 a on the vacuum transfer chamber 310 side is closed. When the transfer arm carrying the wafer W retracts from the load lock chamber 326, the air gate valve 326b is closed. Subsequently, the load lock chamber 326 is evacuated and depressurized to a predetermined pressure. When the pressure reduction is completed, the vacuum gate valve 321 a of the load lock chamber 326 is opened to communicate with the vacuum transfer chamber 310. The vacuum transfer chamber 310 is depressurized in advance.

  The transfer arm 311 of the vacuum transfer chamber 310 is advanced into the load lock 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 321a connecting the load lock chamber 326 and the vacuum transfer chamber 310 is closed.

  Next, the vacuum gate valve 321a of the film forming chamber 321 adjacent to the load lock chamber 326 is opened, and the transfer arm 311 holding the holder H is advanced 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 approach timing of the transfer arm 311.

  The transfer arm 311 places the held holder H on the upper end of the pin 32c. After mounting, 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 lift mechanism 32 is operated to lower the pin 32 c to the stage 31. Thus, the holder H is placed on the stage 31. Then, as shown in FIG. 10, the mounting surface of the stage 31 enters from the opening Ho of the holder H and contacts the wafer W. The electrostatic force acts on the electrostatic chuck 31b on the mounting surface by energization, so the wafer W is attracted and fixed to the upper surface of the electrostatic chuck 31b.

  When the pressure in the chamber 30 is reduced to a predetermined pressure, the sputtering gas is introduced into the film forming chamber 321 from the gas introduction unit 30 b. A direct current voltage is applied from the power supply 34 to the target 33a to plasmify the sputtering gas. The ions generated from the plasma collide with the target 33 a, and the particles of the film forming material of the collided target 33 a fly out and are deposited on the wafer W mounted on the stage 31. Thus, a thin film is formed on the wafer W.

  When the film formation is completed, the application of a voltage to the electrode inside the electrostatic chuck 31b is stopped, and the adsorption and fixation of the wafer W by the electrostatic chuck 31b is released. The lift mechanism 32 lifts the pin 32 c to lift 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 advanced into the chamber 30.

  The wafer W is held by the transfer arm 311 and unloaded from the chamber 30. When the wafer W is unloaded, the vacuum gate valve 321a of the film forming chamber 321 is closed. Subsequently, the vacuum gate valve 322 a of the film forming chamber 322 adjacent to the film forming chamber 321 is opened, and the wafer W is loaded into the chamber 30. As described above, the wafers W are sequentially loaded into the plurality of film forming chambers 321 to 325 to perform necessary film forming processing.

[effect]
(1) As described above, in the film forming apparatus 100 according to the present embodiment, the first setting unit 42 for setting the first area S1 having a predetermined size and the first area S1 are larger than the first area S1. The second setting unit 43 for setting a second area S2 in which all the areas S1 are contained, and the image of the reflected light of the wafer W accommodated and imaged in the holder H are a first area S1 and a second area The detection unit 44 detects a value corresponding to the area of the area overlapping with the area between S2 and the wafer W for the holder H based on whether the value detected by the detection unit 44 exceeds the threshold value. And a determination unit 45 that determines the presence or absence of an abnormality in the position of

  As described above, by using the captured image Sw of the reflected light of the wafer W, it is possible to detect an abnormality in the position of the wafer W having different surface properties using a common detection unit. Furthermore, the detection area D, which is an area overlapping with the area between the first area S1 and the second area S2, changes its area according to the amount of run-up of the wafer W, so it is necessary to determine the center point etc. Even if the wafer W is warped or distorted, the position abnormality can be accurately determined.

(2) The first area S1 has a size in which the image Sw of the reflected light from the wafer W at the normal position accommodated in the holder H is accommodated. For this reason, the extent of run-up can be easily determined by the amount of protrusion from the first area S1.

(3) The first area S1 and the second area S2 are concentric circles. As described above, since the distance between the concentric circles is uniform in the 360 ° direction, it is possible to determine whether the wafer W has run in any direction in the holder H by determining the abnormality based on the overlapping area between the concentric circles.

(4) The input unit 48 instructs to set the first area S1 by the first setting unit 42, and the second setting unit 43 responds to the setting of the first area S1 by the input unit 48. A second area S2 is set. When the first area S1 is set according to the instruction of the input unit 48, the second area S2 is also set, so that the first area S1 and the first area S1 are to be processed when wafers W of different sizes are to be processed. The change of the second area S2 can be easily performed.

(5) The display unit 49 displays information corresponding to the area in which the image Sw of the reflected light overlaps the area between the first area S1 and the second area S2. For this reason, the operator can visually recognize the extent to which the wafer W is lifted.

(6) The display unit 49 displays information indicating an abnormality. Therefore, the operator can visually recognize the abnormality of the position of the wafer W, and can cope with it early.

(7) A single light source 22 for irradiating the wafer W with light, and a camera 21 for imaging the reflected light from the wafer W are included. Thereby, the halation by the plurality of light sources 22 can be suppressed, and an accurate image of the wafer W can be captured. Therefore, the abnormality of the position of the wafer W can be accurately determined with a simple configuration.

[Other embodiments]
(1) The present invention is not limited to the above-described embodiment as it is, and constituent elements can be appropriately modified without departing from the scope of the invention. In addition, a plurality of components disclosed in the above-described embodiment may be combined as appropriate. For example, some components may be deleted from the components described in the above embodiments, and components in different embodiments may be combined as appropriate.

(2) The dimensions of the accommodation portion Hs of the holder H may be as long as the wafer W can be accommodated. However, when the holder H is lifted from the stage 31 by the pins 32 c after the film formation, the wafer W may bounce. This is considered to be caused, for example, by the residual electrostatic force of the electrostatic chuck 31b. At this time, if the depth of the housing portion Hs is shallow, it may run up as it extends out from the holder H, so the housing portion Hs needs a certain depth dp (see FIG. 14). On the other hand, when the depth dp of the housing portion Hs is increased, the holder H shields the film forming material knocked out of the target during film formation, and the film thickness of the outer periphery of the wafer W It will be thinner than the film thickness. As a result of intensive studies, the inventor has found that 1.8 mm ≦ dp ≦ 2.1 mm is preferable. Thereby, it is possible to prevent the uniformity of the film formation and the run-up on the film after the film formation.

(3) The workpiece to be film-formed is not limited to the semiconductor wafer W, and can be applied to various workpieces to be film-formed, such as optical disks such as DVDs and hard disks, mirrors, display panels and solar cell panels. . The shape of the work is not limited to a circle, and may be a polygonal shape such as a square, or may be a three-dimensional object. For example, a polyhedron including a plurality of planes such as a cube and a rectangular solid, a curved body including one or a plurality of curved surfaces such as a hemispherical shape, a dome shape, and a bowl shape, and a curved surface and a plane such as a rectangular cylinder, a cylinder, and a conical shape It may be a complex. In addition, on the surface opposite to the surface on which the film is formed of the wafer W, that is, the surface on which the circuit is formed, a protective adhesive tape may be attached before the film formation.

(4) The first area S1 and the second area S2 are not limited to circular. It may be polygonal according to the shape of the work. In addition, the size of the first region S1 does not have to be larger than the workpiece, and may be smaller than the workpiece. The shape of the holder H may be a shape in accordance with the shape of these workpieces. The holder H should just be a member which mounts a workpiece | work and conveys it, and names, such as a tray and a susceptor, do not matter.

(5) The reflected light from the work may be external illumination or light reflected from natural light. That is, it does not matter what light source is used to obtain the reflected light from the work. In addition, the light source may be a mode in which light is guided by an optical fiber to irradiate the work.

(6) The specific configuration of the film forming unit 300 is not limited to the above embodiment. It may be an in-line type film forming apparatus. A heater may be provided on the stage 31 to perform preheating. The mechanism for holding the holder H may be a mechanical chuck mechanism. In addition, a dedicated chamber 30 for performing preheating may be provided. For example, a pretreatment chamber may be provided between the load lock chamber 326 and the deposition chamber 321, and preliminary heating may be performed in the pretreatment chamber. Further, the pre-processing in the pre-processing chamber may be shared by the load lock chamber 326.

100 film deposition apparatus 200 atmospheric loader 210 holder supply unit 220 wafer supply unit 230 detection mechanism 231 support base 232 elevator board 233 elevator shaft 234 column 235 imaging unit 21 camera 22 light source 300 film forming unit 310 vacuum transfer chamber 311 transfer arm 321 to 325 Deposition chamber 321a to 325a vacuum gate valve 326 load lock chamber 326a vacuum gate valve 326b atmospheric gate valve 30 chamber 30a pressure gauge 30b gas introduction unit 31 stage 31a shaft 31b electrostatic chuck 32 lifting mechanism 32a rod 32b table 32c pin 33 sputtering source 33a target 33b backing plate 33c conductive member 34 power supply 400 control device 40 mechanism control unit 41 display processing unit 42 first setting unit 43 second setting unit 44 detection unit 45 determination unit 46 storage unit 47 input / output control Part 48 input unit 49 display unit

Claims (9)

A first setting unit for setting a first area of a predetermined size;
A second setting unit configured to set a second area larger than the first area and including all the first area;
A detection unit that detects a value corresponding to an area of an area in which an image of light reflected from a workpiece received in a holder and captured overlaps an area between the first area and the second area;
A determination unit that determines the presence or absence of an abnormality in the position of the work relative to the holder based on whether the value detected by the detection unit exceeds a threshold value;
A work detection apparatus characterized by having:   The workpiece detection apparatus according to claim 1, wherein the first area has a size in which an image of reflected light from a workpiece at a normal position accommodated in a holder is accommodated.   3. The work detection apparatus according to claim 1, wherein the first area and the second area are concentric circles. An input unit for instructing setting of a first area by the first setting unit;
The work detection apparatus according to any one of claims 1 to 3, wherein the second setting unit sets the second region in accordance with the setting of the first region by the input unit. .   The work detection apparatus according to any one of claims 1 to 4, further comprising a display unit configured to display information corresponding to the area.   The work detection apparatus according to claim 5, wherein the display unit displays information indicating the abnormality. A single light source that illuminates the workpiece;
An imaging unit configured to image reflected light from the work;
The workpiece | work detection apparatus in any one of the Claims 1 thru | or 6 characterized by these. A workpiece detection device according to any one of claims 1 to 7,
A film forming unit that forms a film on the workpiece whose presence / absence of position abnormality has been determined by the workpiece detection device;
The film-forming apparatus characterized by having. Computer or electronic circuit
A first setting process of setting a first area of a predetermined size;
A second setting process of setting a second area which is larger than the first area and in which the first area is entirely contained;
A detection process for detecting a value corresponding to an area in which an image of light reflected from the workpiece overlaps an area between the first area and the second area;
A determination process of determining presence or absence of an abnormality in the position of the work relative to the holder based on whether or not the value detected by the detection unit exceeds a threshold value;
A work detection method characterized in that:

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