Ion implantation device

Abstract

To provide an ion implanter that reliably stops X-ray irradiation when an operator sets a substrate or performs maintenance.SOLUTION: An ion implanter for implanting ions into a substrate, includes a transport chamber for transferring the substrate to and from the outside, and an X-ray irradiator disposed within the transport chamber, for irradiating the substrate with X-rays prior to ion implantation, and a control unit that stops the irradiation of X-rays by the X-ray irradiator or prevents the activation of the X-ray irradiator when a predetermined condition is detected in the transfer chamber or outside the transfer chamber.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an ion implantation device.

Background Art

[0002] For example, as shown in Patent Document 1, there is an ion implantation device provided with a crystal axis measuring device that irradiates a substrate before ion implantation with X-rays to measure the direction of the crystal axis of the substrate. According to this device, by adjusting the irradiation direction of the ion beam with respect to the substrate based on the measurement result of the crystal axis measuring device, ions can be implanted into the substrate taking channeling into consideration.

[0003] Channeling is a phenomenon in which when ions are implanted along the gaps between atomic rows into a single crystal having a regular atomic arrangement, the ions penetrate deeper into the substrate without colliding with atoms and enter the interior of the crystal.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in an ion implantation device such as that of Patent Document 1, when an operator sets a substrate on the device or performs maintenance on the device, for example, it is necessary to ensure that the X-ray irradiation is stopped.

[0006] That is, the main problem of the present invention is to provide an ion implantation device in which X-ray irradiation is surely stopped when an operator sets a substrate or performs maintenance.

Means for Solving the Problems

[0007] [1] The ion implantation apparatus according to the present invention is An ion implantation apparatus for implanting ions into a substrate, A transport room where the substrate is transferred to and from the outside, An X-ray irradiator is placed in the transport chamber and irradiates the substrate with X-rays before ion implantation, The system includes a control unit that, when it detects a predetermined situation in or outside the transport chamber, stops the irradiation of X-rays by the X-ray irradiator or prevents the X-ray irradiator from starting.

[0008] With an ion implantation apparatus configured in this way, the control unit can stop the irradiation of X-rays by the X-ray irradiator or disable the startup of the X-ray irradiator when it detects a predetermined situation. In other words, the ion implantation apparatus of the present invention ensures that X-ray irradiation is automatically and reliably stopped in a predetermined situation.

[0009] [2] The ion implantation apparatus according to the present invention includes a transport chamber equipped with at least one shielding door that shields X-rays from the X-ray irradiator, and the control unit may stop the irradiation of X-rays by the X-ray irradiator or prevent the X-ray irradiator from starting up when the shielding door is open or unlocked, which is considered a predetermined condition. With this configuration, for example, if the shielding door is opened or unlocked during substrate supply or maintenance by a worker, X-ray irradiation will automatically stop. Furthermore, even if the shielding door is left open or unlocked after the worker's work is completed, X-ray irradiation will not begin, thus preventing X-rays from leaking outside the transport room from the space opened by the shielding door.

[0010] [3] The ion implantation apparatus according to the present invention may be equipped with a door sensor that detects the open / closed state of the shielding door. For door sensors that detect the opening of a shielded door, options include a so-called safety door switch in which the switch body and the operating unit that operates the body are separate, a so-called limit switch in which the door acts as an actuator to operate the switch, and a non-contact proximity sensor that operates the switch contacts using magnetism or other means.

[0011] [4] Preferably, the shielding door is provided on the transport path through which the substrate is transported from the outside to the transport chamber. With this configuration, X-ray irradiation can be stopped when the shielding door is opened to transport the substrate. Furthermore, if the shielding door on the transport path, which is frequently opened, is not properly closed, X-ray irradiation will not start.

[0012] [5] The shielding door may also be an inspection door provided in the transport room.

[0013] [6] The ion implantation apparatus according to the present invention further comprises a door locking / unlocking unit for locking and unlocking the shielding door, and the control unit may be configured to lock the shielding door using the door locking / unlocking unit when the X-ray irradiator is irradiating X-rays. With this configuration, the shielding door is not opened during X-ray irradiation, thus ensuring a higher level of safety for the ion implanter by preventing X-ray leakage outside the transport chamber.

[0014] [7] The control unit may, upon detecting a predetermined situation when a person enters a predetermined area set around the transport chamber, stop the irradiation of X-rays by the X-ray irradiator or disable the activation of the X-ray irradiator. With this configuration, for example, X-ray irradiation can be stopped at the stage when the worker approaches the ion implanter, that is, even before the worker makes contact with the device.

[0015] [8] The ion implantation apparatus according to the present invention includes an implantation chamber into which ions are implanted into the substrate, and may be configured to stop the transfer of the substrate from the transfer chamber to the implantation chamber when the control unit stops the irradiation of X-rays from the X-ray irradiator.

Effect of the Invention

[0016] According to the present invention configured as described above, it is possible to provide an ion implantation apparatus in which the irradiation of X-rays is surely stopped when an operator sets a substrate or performs maintenance.

Brief Description of the Drawings

[0017] [Figure 1] The plan view which shows typically the structure (first shielding door closed state) of the ion implantation apparatus in one Embodiment of this invention. [Figure 2] The plan view which shows typically the structure (first shielding door open state) of the ion implantation apparatus of the embodiment. [Figure 3] The perspective view which shows the ion implantation apparatus of the embodiment. [Figure 4] The plan view which shows typically the structure (second shielding door open state) of the ion implantation apparatus of 2nd Embodiment. [Figure 5] The perspective view which shows the ion implantation apparatus of the second modification of the embodiment.

Mode for Carrying Out the Invention

[0018] [First Embodiment] Hereinafter, an embodiment of an ion implantation apparatus according to the present invention will be described with reference to the drawings.

[0019] 1. Basic Configuration The ion implantation apparatus 100 of the first embodiment is used, for example, in a semiconductor manufacturing process. As shown in Figures 1 and 2, it performs ion implantation by irradiating a substrate S with an ion beam IB inside an implantation chamber IC, which is evacuated to create a high-vacuum environment. The ion implantation apparatus 100 of this embodiment can perform channeling implantation, which allows ions to reach deeper into the substrate S, by irradiating the ion beam IB along the crystal axis of the substrate S.

[0020] The substrate S here has a single-crystal structure and is, for example, a silicon wafer or a silicon carbide wafer. Alternatively, the substrate S may be a base material on which a single-crystal film of silicon, silicon carbide, or the like is formed.

[0021] As shown in Figures 1 to 3, the ion implantation apparatus 100 includes an implantation chamber IC in which ion implantation into the substrate S takes place, and a transport chamber TC adjacent to the implantation chamber IC where the substrate S is transferred to and from the outside. The transport chamber TC is located in an atmospheric pressure environment. The ion implantation apparatus 100 further includes two load lock chambers LLC located between the implantation chamber IC and the transport chamber TC, configured to allow switching between a high vacuum and an atmospheric pressure environment.

[0022] The injection chamber IC and the transport chamber TC are connected via the load lock chamber LLC to allow for the exchange of substrates S, thus forming a so-called end station. Note that the injection chamber IC and the transport chamber TC do not necessarily need to be adjacent; they only need to be connected by the transport path of the substrates S passing through the load lock chamber LLC.

[0023] As shown in Figures 1 and 2, the transport chamber TC is provided with a transport section (not shown) along a predetermined transport path for the substrate S, and an aligner 1 provided on the transport path for positioning the substrate S based on orientation flats or notches formed on the substrate S being transported.

[0024] The transport unit is a robot that transports substrates S inside the transport chamber TC. Specifically, the transport unit transports the substrates S before ion implantation from the substrate setting unit 2a located inside the transport chamber TC to the aligner 1, and then transports the substrates S to the load lock chamber LLC connected to the implantation chamber IC.

[0025] The substrate setting section 2a is the location for supplying substrates S to the ion implantation apparatus 100. In this section, the substrate setting section 2a is the location where an operator sets a case containing multiple substrates S (a so-called substrate cassette SC).

[0026] The transport unit in this embodiment also transports the substrate S after ion implantation, which has been implanted with ions in the implantation chamber IC. Specifically, the transport unit transports the substrate S, which has been implanted with ions in the implantation chamber IC, to the substrate recovery unit 2b provided in the transport chamber TC via the load lock chamber LLC.

[0027] The substrate retrieval section 2b is where the operator retrieves the cassette SC containing the substrate S after ion implantation. In this embodiment, the substrate setting section 2a and the substrate retrieval section 2b are located in different places, but they may be located in a common place.

[0028] 2.Crystal structure analysis department 3 The ion implantation apparatus 100 of this embodiment further includes a crystal structure analysis unit 3 that analyzes the crystal structure (in this case, crystal orientation) of the substrate S before ion implantation.

[0029] As shown in Figures 1 and 2, the crystal structure analysis unit 3 of this embodiment is located in the transport chamber TC and measures the crystal orientation of the substrate S before ion implantation or of a thin film formed on the surface of the substrate S before ion implantation.

[0030] The crystal structure analysis unit 3 includes an X-ray irradiator 31 that irradiates the surface of the substrate S with X-rays, an X-ray detector 32 that detects the X-rays reflected from the surface of the substrate S, and an analyzer 33 that analyzes the crystal structure of the substrate S from the information detected by the X-ray detector 32. Here, the crystal structure analysis unit 3 is provided together with the aligner 1 mentioned above.

[0031] The crystal structure analysis unit 3 irradiates the substrate S, which has been aligned with the orientation flat or notch by the aligner 1, with X-rays to calculate the crystal orientation. Based on this calculated crystal orientation, the ion implantation device 100 adjusts the irradiation angle between the irradiation direction of the ion beam IB and the direction of the crystal axis of the substrate S, and performs the channeling implantation described above.

[0032] This crystal structure analysis unit 3 analyzes the crystal structure of the substrate S based on the same principle as a device widely known as an X-ray diffractometer (XRD), and the X-ray irradiator 31, X-ray detector 32, and analyzer 33 can employ components or configurations widely used in X-ray diffractometers (XRDs).

[0033] The analyzer 33 is physically composed of a CPU, memory, A / D converter, etc., and performs its functions through the cooperation of the CPU and peripheral devices according to a program stored in a predetermined area of ​​the memory.

[0034] 3. Safety Measures Incidentally, considering safety aspects regarding X-rays, it is necessary to ensure that X-ray irradiation from the X-ray irradiator 31 is reliably stopped while the worker is carrying the cassette SC containing the substrate S before ion implantation into the transport room TC, and while the worker is carrying the cassette SC containing the substrate S after ion implantation out of the transport room TC. Furthermore, the ion implanter 100 also needs to prevent X-rays irradiated from the X-ray irradiator 31 from leaking outside the transport chamber TC. Therefore, the ion implanter 100 of this embodiment is equipped with a shielding structure that physically shields X-rays that would otherwise leak outside the device, and a function that reliably stops X-ray irradiation when an operator loads or unloads cassettes SC or performs maintenance work inside the transport chamber TC. These will be described below.

[0035] 3-1. Shielding wall 4 of transport room TC First, the shielding wall 4 forming the transport chamber TC is configured to have the function of shielding against X-rays. This shielding wall 4 may be made of X-ray shielding material itself, or it may have X-ray shielding material on its surface or inside.

[0036] The shielding wall 4 shields X-rays from the X-ray irradiator 31 located in the transport chamber TC to the outside. Specifically, as shown in Figures 1 to 3, the shielding wall 4 is provided so as to surround the transport chamber TC and constitutes at least the side wall of the transport chamber TC. In addition to this side wall, the shielding wall 4 may also constitute the upper or lower wall of the transport chamber TC.

[0037] The configuration of the shielding wall 4 (number and arrangement) is not limited to the above, and it is sufficient as long as it is configured so that the X-rays generated from the X-ray irradiator 31 do not leak to the outside of the ion implanter 100.

[0038] 3-2. First shielding door 5 As shown in Figures 1 to 3, the shielding wall 4 is provided with a first shielding door 5 for opening and closing the transport chamber TC. The first shielding door 5 is a plate-shaped structure made of X-ray shielding material and is a hinged door. In this embodiment, the shielding wall 4 is provided with two first shielding doors 5, which are positioned in front of the substrate setting section 2a and the substrate retrieval section 2b, respectively. When the first shielding doors 5 are opened, the worker can set a cassette SC in the substrate setting section 2a or retrieve a cassette SC from the substrate retrieval section 2b. Note that the number and arrangement of the first shielding doors 5 are not limited to these.

[0039] The ion implantation apparatus 100 of this embodiment is equipped with a first door sensor 51 that detects the open / closed state of the first shielding door 5. When the first shielding door 5 is open, the first door sensor 51 outputs a detection signal to the control unit 6, which will be described later, indicating that it has detected an open state. The first door sensor 51 of this embodiment is a safety door switch composed of a main body 51a fixed to the opening of the first shielding door 5 and an operating part 51b fixed to the inside of the first shielding door 5.

[0040] The operating unit 51b is inserted into the main body 51a when the first shielding door 5 is closed. In this inserted state, a contact switch provided inside the main body 51a is pressed by the operating unit 51b and closes, and the main body 51a detects that the first shielding door 5 is closed. On the other hand, when the first shielding door 5 is open, the operating unit 51b is detached from the main unit 51a. In this detached state, the contact switch is opened, and the main unit 51a detects that the first shielding door 5 is open.

[0041] The first door sensor 51 can be a limit switch activated by the door acting as an actuator, a non-contact proximity sensor that activates the switch contacts using magnetism, or the like. The first door sensor 51 may also be a camera or the like.

[0042] 3-3. Control Unit 6 As shown in FIGS. 1 and 2, when a predetermined situation is detected in the transfer chamber TC or outside the transfer chamber TC, the ion implantation apparatus 100 of the present embodiment further includes a control unit 6 that performs interlock control to stop the irradiation of X-rays by the X-ray irradiator 31 or disable the activation of the X-ray irradiator 31. Although the control unit 6 is shown outside the apparatus in each figure, this is for convenience, and the actual control unit 6 is provided inside the ion implantation apparatus 100.

[0043] Here, the predetermined situation refers to, for example, a situation where an operator who supplies the substrate S to the ion implantation apparatus 100 opens the first shielding door 5 or a second shielding door 7 described later, or a situation where the operator enters a predetermined area outside the transfer chamber TC.

[0044] As shown in FIGS. 2 and 3, the control unit 6 here detects the state where the first shielding door 5 is open as a predetermined situation. More specifically, when the first door sensor 51 detects the opening of the first shielding door 5, the control unit 6 transmits a stop command signal for instructing to stop the irradiation of X-rays from the X-ray irradiator 31, or a start-disable command signal for instructing to disable the activation of the X-ray irradiator 31 to the crystal structure analysis unit 3. Note that the control unit 6 may transmit both the stop command signal and the start-disable command signal to the crystal structure analysis unit 3.

[0045] Physically, the control unit 6 is composed of a CPU, a memory, an A / D converter, etc., and the CPU and peripheral devices cooperate according to a program stored in a predetermined area of the memory to exert the function of the above interlock control. Here, it is provided in the transfer chamber TC.

[0046] 4. Interlock Control by the Control Unit 6 The interlock control of the crystal structure analysis unit 3 by the control unit 6 will be specifically described separately for the case where X-rays are being irradiated from the crystal structure analysis unit 3 and the case where X-rays are not being irradiated.

[0047] <When X-rays are being irradiated> When the substrate S is irradiated with X-rays inside the transfer chamber TC, for example, if an operator opens the first shielding door 5 for supplying or retrieving the substrate S, the control unit 6 stops the irradiation of X-rays from the X-ray irradiator 31. Thereafter, when the first shielding door 5 is closed, the control unit 6 automatically resumes the irradiation of X-rays from the X-ray irradiator 31. The irradiation of X-rays from the X-ray irradiator 31 may resume when a predetermined instruction is received from the operator after the first shielding door 5 is closed.

[0048] <When the substrate is not irradiated with X-rays> When the substrate S is not irradiated with X-rays inside the transfer chamber TC, for example, if an operator opens the first shielding door 5 for supplying or retrieving the substrate S, the control unit 6 disables the activation of the X-ray irradiator 31. Thereafter, when the first shielding door 5 is closed, the control unit 6 enables the activation of the X-ray irradiator 31.

[0049] 5. Effects According to the ion implantation apparatus 100 of the present embodiment configured as described above, in a predetermined situation (here, a situation where the first shielding door 5 is open), X-rays are not irradiated by interlock control, so that an operator performing an operation such as supplying the substrate S can work safely. Further, since the irradiation of X-rays is not started when the first shielding door 5 is not properly closed or is forgotten to be closed, leakage of X-rays generated from the X-ray irradiator 31 to the outside of the transfer chamber TC after the operation is prevented.

[0050] The ion implantation apparatus 100 further includes a second shielding door 7 provided on the side surface of the transfer chamber TC as shown in FIG. 4 and a second door sensor 71 for detecting the open / closed state of the second shielding door 7. The second shielding door 7 here is in a plate shape using an X-ray shielding material, similar to the first shielding door 5. Also, the second door sensor 71 here is a safety door switch, similar to the first door sensor 51.

[0051] The second shielding door 7 in this embodiment is a door provided for workers to perform maintenance and inspections inside the transport room TC. The second shielding door 7 is configured so that workers can access the equipment installed inside the transport room TC from outside the transport room TC through the open second shielding door 7. In this case, the second shielding door 7 is positioned so that workers can access the X-ray irradiator 31 or the X-ray detector 32. Note that the second shielding door 7 may also be an inspection door provided inside the transport room TC, or it may be positioned so that equipment other than the crystal structure analysis unit 3 can be accessed from the second shielding door 7.

[0052] When this second shielding door 7 is opened, workers can inspect, maintain, and repair the equipment located inside the transport room TC. Furthermore, when this second shielding door 7 is open, an interlock is applied to the crystal structure analysis unit 3, ensuring that the generation of X-rays from the X-ray irradiator 31 is reliably stopped. Therefore, workers can safely perform inspections and other tasks.

[0053] [First variation] As shown in Figure 4, the ion implanter 100 is equipped with a human detection sensor 72 located near the second shielding door 7 of the shielding wall 4. The human detection sensor 72 detects a dangerous situation when a person enters a predetermined area set around the outside of the transport chamber TC. The control unit 6 controls the X-ray irradiator 31 to stop or disable its operation based on the output of the human detection sensor 72. The human detection sensor 72 here is, for example, an infrared sensor using PIR mounted on the outside of the shielding wall 4. The human detection sensor 72 may be any other infrared sensor, or it may be an ultrasonic sensor, microwave sensor, or sound sensor. The human detection sensor may also be located near the first shielding door 5.

[0054] With this configuration, the X-ray irradiation can be stopped by interlock control when the worker approaches the second shielding door 7, that is, before the worker opens the second shielding door 7.

[0055] [Second variation] As shown in Figure 5, the ion implantation apparatus 100 may be equipped with a door locking / unlocking unit 53 for locking and unlocking the first shielding door 5. The door locking / unlocking unit 53 may also lock and unlock the second shielding door 7. In this modification, the door locking / unlocking unit 53 consists of a locking body 53a fixed to the shielding wall 4 and a key 53b. The first shielding door 5 is unlocked when the operator inserts the key 53b into the opening of the locking body 53a. The first shielding door 5 is locked when the operator pulls the key 53b out of the opening of the locking body 53a.

[0056] Figure 5 shows a configuration in which a door locking / unlocking unit 53 is provided in place of the first door sensor, but the door locking / unlocking unit 53 may also be provided in combination with the first door sensor. Furthermore, the first door sensor or the second door sensor may have the function of locking or unlocking the first shielding door 5 or the second shielding door 7. In this modified example, the control unit 6 detects, in addition to (or instead of) the state in which the first shielding door 5 or the second shielding door 7 is open, a state in which the door locking / unlocking unit 53 is unlocked (unlocked) as a predetermined condition.

[0057] In this modified example, for instance, when a worker unlocks the first shielding door 5, the control unit 6 performs interlock control, stopping the irradiation of X-rays from the X-ray irradiator 31. If the door is unlocked, the lock by the control unit 6 remains engaged even if the worker opens or closes the first shielding door 5. Subsequently, when the first shielding door 5 is locked, the interlock is released from the control unit 6. This ensures that the interlock is engaged before the worker actually opens the first shielding door 5. Therefore, when a worker loads or unloads a cassette SC, etc., the irradiation of X-rays from the X-ray irradiator 31 can be reliably stopped.

[0058] In this modified configuration, the control unit 6 may also lock the first shielding door 5 or the second shielding door 7 using the door locking / unlocking unit 53 when the X-ray irradiator 31 is irradiating X-rays. In this case, the first shielding door 5 or the second shielding door 7 will not be opened while X-ray irradiation is in progress.

[0059] The ion implantation apparatus 100 is equipped with a plurality of first shielding doors 5 and second shielding doors 7, each serving a different purpose. The control unit 6 may detect a predetermined condition in which at least one of these shielding doors 5 and 7 is open or unlocked.

[0060] The ion implanter 100 may be configured to stop transporting the substrate S from the transport chamber TC to the implantation chamber IC when the control unit 6 stops irradiating with X-rays from the X-ray irradiator 31. In this case, substrates S that have not been irradiated with X-rays, i.e., substrates S whose crystal orientation has not been measured, will not be transported to the implantation chamber IC.

[0061] Furthermore, various modifications and combinations of the embodiments are permitted, as long as they do not contradict the spirit of the present invention. [Explanation of Symbols]

[0062] IB...Ion Beam S ··· circuit board SC ··· Circuit board cassette 100... Ion implantation device 1 ···Alaina 2a ···Board set section 2b ···Circuit board recovery section 3...Crystal structure analysis department 31...X-ray irradiator 32 ···X-ray detector 4...shielding wall 5. First shielding door 51...First door sensor 6. Control Unit 7. Second shielding door 71...Second door sensor IC...Injection chamber TC ··· Transport Room LLC... Load Lock Room

Claims

1. An ion implantation apparatus for implanting ions into a substrate, A transport room where the substrate is transferred to and from the outside, An X-ray irradiator is placed in the transport chamber and irradiates the substrate with X-rays before ion implantation, The system includes a control unit that, when it detects a predetermined situation in or outside the transport chamber, stops the irradiation of X-rays by the X-ray irradiator or disables the activation of the X-ray irradiator, Inside the transport chamber, which is formed by being surrounded by a shielding wall, there is a substrate setting section where an operator sets the substrate and a substrate retrieval section where an operator retrieves the substrate. The shielding wall is provided with shielding doors positioned in front of the substrate setting section and the substrate retrieval section, respectively, to shield X-rays from the X-ray irradiator. The control unit is an ion implantation device that, when the shielding door is open or unlocked, sets a predetermined condition, stops the irradiation of X-rays by the X-ray irradiator or prevents the X-ray irradiator from starting.

2. The ion implantation apparatus according to claim 1, further comprising a door sensor for detecting the open / closed state of the shielding door.

3. The ion implantation apparatus according to claim 1, wherein the shielding door is provided on a transport path through which the substrate is transported from the outside to the transport chamber.

4. The transport chamber is further provided with a second shielding door, which is an inspection door, The ion implantation apparatus according to claim 1, wherein the control unit determines that the second shielding door is open or unlocked as the predetermined condition, and stops the irradiation of X-rays by the X-ray irradiator or prevents the X-ray irradiator from starting.

5. The door locking / unlocking unit for locking and unlocking the aforementioned shielding door is further provided. The ion implantation apparatus according to claim 1, wherein the control unit locks the shielding door with the door locking / unlocking unit when the X-ray irradiator is irradiating X-rays.

6. The ion implantation apparatus according to claim 1, wherein the control unit detects a predetermined situation when a person enters a predetermined area set around the transport chamber, and stops the irradiation of X-rays by the X-ray irradiator or prevents the X-ray irradiator from starting.

7. The substrate is equipped with an implantation chamber into which ions are implanted, The ion implantation apparatus according to any one of claims 1 to 6, wherein the transport of the substrate from the transport chamber to the implantation chamber is stopped when the control unit stops the irradiation of X-rays from the X-ray irradiator.

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