Ion implantation device

Abstract

The invention provides an ion implantation apparatus which can reliably stop X-ray irradiation when a worker sets a substrate or performs maintenance. An ion implantation device for implanting ions into a substrate, the ion implantation device comprising: a transfer chamber for transferring the substrate to and from the outside; an X-ray irradiator which is disposed in the transfer chamber and irradiates the substrate before ion implantation with X-rays; and a control unit that, when a predetermined condition is detected in the transport chamber or outside the transport chamber, stops the X-ray irradiation of the X-ray irradiator or disables the X-ray irradiator from being activated.

Description

Technical Field

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

[0002] For example, as described in Patent Document 1, there is an ion implantation apparatus equipped with a crystal axis measuring device. This device measures the direction of the substrate's crystal axis by irradiating the substrate with X-rays before ion implantation. This apparatus adjusts the direction of ion beam irradiation on the substrate based on the measurement results of the crystal axis measuring device, making it possible to implant ions into the substrate while taking into account the channeling effect.

[0003] Channeling refers to a phenomenon in which, when ions are implanted along the gaps between the atomic rows into a single crystal having a regular atomic arrangement, the ions penetrate into the crystal without colliding with the atoms, thereby reaching deeper into the substrate.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2021-120944 Summary of the Invention

[0007] [Problems to be Solved by the Invention]

[0008] However, in the ion implantation apparatus disclosed in Patent Document 1, when a worker sets a substrate in the apparatus or performs maintenance on the apparatus, it is necessary to reliably stop X-ray irradiation.

[0009] That is, a main object of the present invention is to provide an ion implantation apparatus that reliably stops X-ray irradiation when a worker sets a substrate or performs maintenance.

[0010] [Means for solving the problem] [1]

[0012] The ion implantation apparatus of the present invention is an ion implantation apparatus for implanting ions into a substrate, wherein: The ion implantation device comprises: a transport chamber for transferring the substrate to and from the outside; An X-ray irradiator is disposed in the transport chamber and irradiates the substrate before ion implantation with X-rays; and The control unit stops the X-ray irradiator from irradiating X-rays or disables the X-ray irradiator from being activated when a predetermined condition is detected in the transport room or outside the transport room.

[0013] The ion implantation apparatus thus configured can stop the X-ray irradiator from emitting X-rays or disable the X-ray irradiator when the control unit detects a predetermined condition. That is, the ion implantation apparatus of the present invention automatically and reliably stops X-ray irradiation under predetermined conditions. [2]

[0015] The ion implantation device involved in the present invention may be that the transport chamber has at least one shielding door, which shields the X-rays from the X-ray irradiator, and the control unit uses the state of the shielding door being open or the state of the shielding door being unlocked as the prescribed condition, and stops the X-ray irradiator from irradiating X-rays or prevents the X-ray irradiator from starting.

[0016] According to this configuration, for example, when a worker supplies a substrate or performs maintenance, if the shield door is opened or unlocked, X-ray irradiation is automatically stopped.

[0017] Furthermore, even when the shield door remains open or unlocked after the worker's work, X-ray irradiation does not start, thereby preventing X-rays from leaking to the outside of the transport room from the space opened by the shield door. [3]

[0019] The ion implantation apparatus according to the present invention may include a door sensor that detects an open or closed state of the shield door.

[0020] As a door sensor for detecting the opening of the shielding door, for example, a so-called safety door switch in which the switch body is separated from the operating part of the operating body, a so-called limit switch in which the door acts as an actuator to activate the switch, a non-contact proximity sensor that activates the contacts of the switch through magnetic force, etc. can be selected. [4]

[0022] It is preferable that the screen door is provided on a transport path for transporting the substrate from the outside to the transport chamber.

[0023] According to this structure, when the shield door is opened for conveying a substrate, X-ray irradiation can be stopped. In addition, for the shield door on the conveying path with a high opening frequency, X-ray irradiation is not started unless it is properly closed. [5]

[0025] The screen door may be a maintenance door provided in the transport room. [6]

[0027] The ion implantation device involved in the present invention can also be constructed as follows: the ion implantation device further includes a door locking and unlocking unit, which locks and unlocks the shielding door. When the X-ray irradiator irradiates X-rays, the control unit locks the shielding door through the door locking and unlocking unit.

[0028] With this configuration, the shield door does not open during X-ray irradiation, thereby ensuring higher safety of the ion implantation apparatus by preventing X-rays from leaking to the outside of the transfer chamber. [7]

[0030] When a person enters a predetermined area set around the transport room, the control unit may regard that the predetermined situation has been detected and stop the X-ray irradiator from irradiating X-rays or disable the X-ray irradiator from being activated.

[0031] According to this configuration, for example, X-ray irradiation can be stopped at a stage when a worker approaches the ion implantation apparatus, that is, at a stage before the worker comes into contact with the apparatus. [8]

[0033] The ion implantation apparatus according to the present invention may include an implantation chamber that implants ions into the substrate, and when the control unit stops irradiating X-rays from the X-ray irradiator, stops transporting the substrate from the transport chamber to the implantation chamber.

[0034] [Effects of the Invention]

[0035] According to the present invention thus constituted, it is possible to provide an ion implantation apparatus that reliably stops X-ray irradiation when a worker sets a substrate or performs maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a plan view schematically showing the structure of the ion implantation apparatus (first shield door closed state) according to one embodiment of the present invention.

[0037] Figure 2 It is a plan view schematically showing the structure of the ion implantation apparatus according to this embodiment (first shield door opened state).

[0038] Figure 3 It is a perspective view showing the ion implantation apparatus according to this embodiment.

[0039] Figure 4 It is a plan view schematically showing the structure of the ion implantation apparatus according to the second embodiment (second shield door open state).

[0040] Figure 5It is a perspective view showing an ion implantation apparatus according to a second modified example of the embodiment.

[0041] [Explanation of Reference Numerals]

[0042] IB…Ion Beam

[0043] S…Substrate

[0044] SC…Substrate Box

[0045] 100…Ion implantation device

[0046] 1…Alignment tool

[0047] 2a...Substrate installation portion

[0048] 2b…Substrate recovery department

[0049] 3…Crystal Structure Analysis Department

[0050] 31…X-ray irradiator

[0051] 32…X-ray detector

[0052] 4…Shielding wall

[0053] 5…First platform door

[0054] 51…First door sensor

[0055] 6…Control Unit

[0056] 7…Second platform door

[0057] 71…Second door sensor

[0058] IC…Injection Chamber

[0059] TC…Transportation Room

[0060] LLC…Load Lock Chamber DETAILED DESCRIPTION

[0061] [First embodiment]

[0062] Hereinafter, one embodiment of the ion implantation apparatus according to the present invention will be described with reference to the drawings.

[0063] 1. Basic structure

[0064] The ion implantation apparatus 100 of the first embodiment is used, for example, in a semiconductor manufacturing process. Figure 1 and Figure 2As shown, ion implantation is performed by irradiating the substrate S with an ion beam IB in an implantation chamber IC that has been evacuated to 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.

[0065] The substrate S here has a single crystal structure, and is, for example, a silicon wafer, a silicon carbide wafer, etc. Alternatively, the substrate S may be a substrate having a single crystal film of silicon, silicon carbide, or the like formed on the surface of a base material.

[0066] like Figures 1 to 3 As shown, the ion implantation apparatus 100 includes an implantation chamber IC for performing ion implantation onto the aforementioned substrate S, and a transfer chamber TC, located adjacent to the implantation chamber IC, for transferring the substrate S to and from the outside. The transfer chamber TC is located under atmospheric pressure. The ion implantation apparatus 100 further includes two load lock chambers LLC, which are located between the implantation chamber IC and the transfer chamber TC and are configured to switch between high vacuum and atmospheric pressure.

[0067] The implantation chamber IC and the transfer chamber TC are connected via the load lock chamber LLC to form a so-called terminal station. The implantation chamber IC and the transfer chamber TC do not necessarily need to be adjacent to each other, but may be connected on the transfer path of the substrate S passing through the load lock chamber LLC.

[0068] like Figure 1 and Figure 2 As shown, the transport chamber TC is provided with: a transport device (not shown) arranged along a prescribed transport path of the substrate S; and an aligner 1 arranged on the transport path for positioning the substrate S based on an orientation plane or notch formed on the substrate S being transported.

[0069] The transport device is a robot that transports the substrate S within the transport chamber TC. Specifically, the transport device transports the substrate S before ion implantation from the substrate setting portion 2a provided within the transport chamber TC to the aligner 1 and transports the substrate S to the load lock chamber LLC connected to the implantation chamber IC.

[0070] The substrate setting portion 2a is a portion for supplying substrates S to the ion implantation apparatus 100. The substrate setting portion 2a is a portion where a worker sets a housing (so-called substrate cassette SC) storing a plurality of substrates S.

[0071] The transport device of this embodiment also carries out the substrate S implanted with ions in the implantation chamber IC. Specifically, the transport device carries out the substrate S 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.

[0072] The substrate collecting portion 2b is where a worker collects the cassette SC containing the ion-implanted substrates S. In this embodiment, the substrate setting portion 2a and the substrate collecting portion 2b are provided at different locations, but may be provided at a common location.

[0073] 2. Crystal structure analysis part 3

[0074] The ion implantation apparatus 100 of the present embodiment further includes a crystal structure analysis unit 3 that analyzes the crystal structure (here, crystal orientation) of the substrate S before ion implantation.

[0075] like Figure 1 and Figure 2 As shown, the crystal structure analysis unit 3 of this embodiment is disposed in the transfer chamber TC and measures the crystal orientation of the substrate S before ion implantation or a thin film formed on the surface of the substrate S before ion implantation.

[0076] The crystal structure analysis unit 3 includes an X-ray irradiator 31 for irradiating the processed surface of the substrate S with X-rays; an X-ray detector 32 for detecting X-rays reflected from the processed surface of the substrate S; and an analyzer 33 for analyzing the crystal structure of the substrate S based on the information detected by the X-ray detector 32. The crystal structure analysis unit 3 is provided together with the aligner 1 described above.

[0077] The crystal structure analysis unit 3 irradiates the substrate S, which has been subjected to orientation plane alignment or notch alignment by the aligner 1, with X-rays to calculate the crystal orientation. Then, based on the calculated crystal orientation, the ion implantation apparatus 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 aforementioned channeling implantation.

[0078] The crystal structure analysis unit 3 analyzes the crystal structure of the substrate S based on the same principle as an X-ray diffraction apparatus (XRD). The X-ray irradiator 31 , the X-ray detector 32 , and the analyzer 33 can adopt components or structures widely used in X-ray diffraction apparatuses (XRD).

[0079] The analyzer 33 is physically composed of a CPU, a memory, an A / D converter, and the like, and functions as a result of the CPU and peripheral devices cooperating in accordance with a program stored in a predetermined area of ​​the memory.

[0080] 3. Security measures

[0081] However, if the safety aspect of X-rays is taken into consideration, it is necessary to reliably stop the X-ray irradiation from the X-ray irradiator 31 while the staff is moving the box SC containing the substrate S before ion implantation into the conveying chamber TC and while the staff is moving the box SC containing the substrate S after ion implantation out of the conveying chamber TC.

[0082] Furthermore, in the ion implantation apparatus 100, it is necessary to prevent X-rays emitted from the X-ray irradiator 31 from leaking outside the transport chamber TC. Therefore, the ion implantation apparatus 100 of this embodiment includes a shielding structure that physically blocks X-rays that might leak outside the apparatus, and a function that reliably stops X-ray irradiation when workers are loading and unloading cassettes SC or performing maintenance work inside the transport chamber TC. These functions are described below.

[0083] 3-1. Shielding wall 4 of transport chamber TC

[0084] First, the shielding wall 4 forming the transfer chamber TC has a function of shielding X-rays. The shielding wall 4 may be made of an X-ray shielding material itself, or may have an X-ray shielding material on its surface or inside.

[0085] The shielding wall 4 shields X-rays from the X-ray irradiator 31 provided in the transport chamber TC to the outside. Figures 1 to 3 As shown, the shielding wall 4 is provided so as to surround the transfer chamber TC and constitutes at least a side wall of the transfer chamber TC. In addition to the side wall, the shielding wall 4 may constitute an upper wall or a lower wall of the transfer chamber TC.

[0086] The structure (number or arrangement) of the shielding wall 4 is not limited to that described above, and any structure may be used as long as the X-rays generated by the X-ray irradiator 31 do not leak to the outside of the ion implantation apparatus 100 .

[0087] 3-2. First platform door 5

[0088] like Figures 1 to 3 As shown, 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 in the form of a plate made of X-ray shielding material and is a swing door in this embodiment. In this embodiment, the shielding wall 4 is provided with two first shielding doors 5, one located in front of the substrate installation section 2a and the other located in front of the substrate collection section 2b. When the first shielding doors 5 are opened, a worker can place a cassette SC in the substrate installation section 2a or retrieve a cassette SC from the substrate collection section 2b. The number and arrangement of the first shielding doors 5 are not limited to this.

[0089] The ion implantation apparatus 100 of this embodiment includes a first door sensor 51 that detects the open / closed state of the first shield door 5. When the first shield door 5 is open, the first door sensor 51 outputs a detection signal indicating, for example, detection of the open state to the control unit 6, described later. 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 shield door 5 and an operating unit 51b fixed to the inside of the first shield door 5.

[0090] The operating unit 51b is inserted into the main body 51a when the first screen door 5 is closed. In this inserted state, the contact switch provided inside the main body 51a is pressed by the operating unit 51b and closed, and the main body 51a detects that the first screen door 5 is closed.

[0091] On the other hand, when the first screen door 5 is in the open state, the operating portion 51b is pulled out from the main body 51a. In this pulled out state, the contact switch is turned on, and the main body 51a detects that the first screen door 5 is in the open state.

[0092] Furthermore, a limit switch that operates a switch using a door as an actuator, a non-contact proximity sensor that operates a switch contact by magnetic force, etc., etc. can be used as the first door sensor 51. The first door sensor 51 may also be a camera, etc.

[0093] 3-3. Control Unit 6

[0094] like Figure 1 and Figure 2 As shown, the ion implantation apparatus 100 of this embodiment further includes a control unit 6. When a predetermined condition is detected in or outside the transfer chamber TC, the control unit 6 performs interlock control to stop the X-ray irradiator 31 from emitting X-rays or to disable the activation of the X-ray irradiator 31. In the various figures, the control unit 6 is depicted outside the apparatus for convenience; in reality, the control unit 6 is located inside the ion implantation apparatus 100.

[0095] Here, the predetermined situation refers to, for example, a situation in which a worker supplying the substrate S to the ion implantation apparatus 100 opens the first shield door 5 or the second shield door 7 described later, or a situation in which a worker enters a predetermined area outside the transfer chamber TC.

[0096] like Figure 2 as well as Figure 3 As shown, the control unit 6 here detects the open state of the first shielding door 5 as a predetermined condition. 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 instructing the X-ray irradiator 31 to stop irradiation with X-rays, or a disable command signal instructing the X-ray irradiator 31 to disable activation, to the crystal structure analysis unit 3. Alternatively, the control unit 6 may transmit both the stop command signal and the disable command signal to the crystal structure analysis unit 3.

[0097] The control unit 6 is physically composed of a CPU, memory, A / D converter, etc. The CPU and peripheral devices cooperate according to a program stored in a predetermined area of ​​the memory to perform the interlock control function. Here, the control unit 6 is installed in the transport chamber TC.

[0098] 4. Interlocking control of control unit 6

[0099] The interlock control of the crystal structure analysis unit 3 by the control unit 6 will be specifically described with reference to a case where X-rays are irradiated from the crystal structure analysis unit 3 and a case where X-rays are not irradiated.

[0100] <In the case of X-ray exposure>

[0101] When X-rays are irradiated onto the substrates S within the transport chamber TC, for example, when a worker opens the first shielding door 5 to supply or retrieve the substrates S, the controller 6 stops the X-ray irradiator 31. Thereafter, when the first shielding door 5 is closed, the controller 6 automatically resumes the X-ray irradiator 31. X-ray irradiation from the X-ray irradiator 31 may also be resumed upon receipt of a predetermined instruction from a worker after the first shielding door 5 is closed.

[0102] <When X-rays are not irradiated>

[0103] When the substrate S is not being irradiated with X-rays inside the transport chamber TC, for example, when a worker opens the first shield door 5 to supply or collect the substrate S, the controller 6 disables the activation of the X-ray irradiator 31. Thereafter, when the first shield door 5 is closed, the controller 6 can activate the X-ray irradiator 31.

[0104] 5. Effect

[0105] According to the ion implantation apparatus 100 of this embodiment configured in this manner, X-ray irradiation is not performed under a predetermined condition (here, when the first shield door 5 is open) without interlock control. Therefore, workers performing operations such as supplying substrates S can safely perform their work. Furthermore, X-ray irradiation is not initiated if the first shield door 5 is not properly and completely closed, or if it is forgotten to be closed. This prevents X-rays generated by the X-ray irradiator 31 from leaking outside the transport chamber TC after the operation.

[0106] like Figure 4 As shown, the ion implantation apparatus 100 further includes a second shielding door 7 provided on the side of the transfer chamber TC, and a second door sensor 71 for detecting the open / closed state of the second shielding door 7. The second shielding door 7, like the first shielding door 5, is in the form of a plate made of X-ray shielding material. Furthermore, the second door sensor 71, like the first door sensor 51, is a safety door switch.

[0107] The second shielding door 7 of this embodiment is provided for personnel to perform maintenance and inspection within the transport chamber TC. The second shielding door 7 is configured so that personnel can access the equipment within the transport chamber TC from outside the transport chamber TC through the opened second shielding door 7. The second shielding door 7 is positioned so that personnel can access the X-ray irradiator 31 or the X-ray detector 32. Alternatively, the second shielding door 7 may be a maintenance door provided within the transport chamber TC, or may be configured so that personnel can access equipment other than the crystal structure analysis unit 3 from the second shielding door 7.

[0108] When the second shield door 7 is open, workers can inspect, maintain, and repair equipment located within the transport chamber TC. Furthermore, when the second shield door 7 is open, the crystal structure analysis unit 3 is interlocked, reliably stopping the generation of X-rays from the X-ray irradiator 31. This allows workers to safely perform inspection and other maintenance tasks.

[0109] [First Modification]

[0110] like Figure 4 As shown, the ion implantation apparatus 100 includes a human detection sensor 72 disposed near the second shielding door 7 of the shielding wall 4. The human detection sensor 72 detects a situation in which a person enters a predetermined area set around the outside of the transfer chamber TC as a dangerous situation. The control unit 6 controls the X-ray irradiator 31 to stop or prevent the X-ray irradiator 31 from being started based on the output of the human detection sensor 72. The human detection sensor 72 here is, for example, an infrared sensor using a PIR or the like installed on the outside of the shielding wall 4. In addition, the human detection sensor 72 may be another infrared sensor, or may be an ultrasonic sensor, a microwave sensor, or an acoustic sensor. In addition, the human detection sensor may also be disposed near the first shielding door 5.

[0111] With such a configuration, X-ray irradiation can be stopped by interlock control at a stage when a worker approaches the second shield door 7 , that is, before the worker opens the second shield door 7 .

[0112] [Second Modification]

[0113] like Figure 5As shown, the ion implantation apparatus 100 may also include a door locking and unlocking unit 53 for locking and unlocking the first shielding door 5. Furthermore, the door locking and unlocking unit 53 may also lock and unlock the second shielding door 7. The door locking and unlocking unit 53 in this modified example comprises a locking body 53a fixed to the shielding wall 4 and a key 53b. When a worker inserts the key 53b into the opening of the locking body 53a, the first shielding door 5 is unlocked. Furthermore, when a worker removes the key 53b from the opening of the locking body 53a, the first shielding door 5 is locked.

[0114] Figure 5 Although the structure shown is provided with the door locking and unlocking unit 53 instead of the first door sensor 51, the structure may also be provided with the door locking and unlocking unit 53 in conjunction with the first door sensor 51. In addition, the first door sensor 51 or the second door sensor 71 may also have the function of locking and unlocking the first screen door 5 or the second screen door 7.

[0115] In this modification, the control unit 6 detects the unlocked state (unlocked state) of the door lock unlocking unit 53 as a predetermined condition in addition to (or instead of) detecting the open state of the first screen door 5 or the second screen door 7 .

[0116] In this modified example, for example, when a worker unlocks the locked first shielding door 5, the control unit 6 performs interlock control to stop X-ray irradiation from the X-ray irradiator 31. While unlocked, the control unit 6 maintains the locked state even if the worker opens and closes the first shielding door 5. Subsequently, when the first shielding door 5 is locked, the control unit 6 releases the interlock. In this way, the interlock is activated before the worker actually opens the first shielding door 5. Therefore, X-ray irradiation from the X-ray irradiator 31 can be reliably stopped, for example, when the worker is loading or unloading a cassette SC.

[0117] In addition, the control unit 6 of this modification can also lock the first shielding door 5 or the second shielding door 7 via the door locking and unlocking unit 53 when the X-ray irradiator 31 is irradiating X-rays. In this way, the first shielding door 5 or the second shielding door 7 is not opened during X-ray irradiation.

[0118] The ion implantation apparatus 100 includes a plurality of first and second shield doors 5 and 7 having different uses. The control unit 6 may detect that at least one of the shield doors 5 and 7 is open or unlocked as a predetermined state.

[0119] The ion implantation apparatus 100 may be configured to stop transporting the substrate S from the transport chamber TC to the implantation chamber IC when the controller 6 stops irradiating X-rays from the X-ray irradiator 31. In this manner, substrates S that have not been irradiated with X-rays, i.e., substrates S whose crystal orientation has not been measured, are not transported to the implantation chamber IC.

[0120] Furthermore, various embodiments may be modified or combined as long as they do not depart from the spirit of the present invention.

Claims

1. An ion implantation apparatus for implanting ions into a substrate, wherein: The ion implantation device comprises: a transport chamber for transferring the substrate to and from the outside; An X-ray irradiator is disposed in the transport chamber and irradiates the substrate before ion implantation with X-rays; and The control unit stops the X-ray irradiator from irradiating X-rays or disables the X-ray irradiator from being activated when a predetermined condition is detected in the transport room or outside the transport room.

2. The ion implantation apparatus according to claim 1, wherein: The transport chamber includes at least one shielding door for shielding X-rays from the X-ray irradiator. The control unit stops the X-ray irradiator from irradiating X-rays or disables the X-ray irradiator from being activated, based on the state in which the shielding door is open or unlocked as the predetermined state.

3. The ion implantation apparatus according to claim 2, wherein: The ion implantation apparatus includes a door sensor that detects an open or closed state of the shield door.

4. The ion implantation apparatus according to claim 2, wherein: The shield door is provided on a transport path for transporting the substrate from the outside to the transport chamber.

5. The ion implantation apparatus according to claim 2, wherein: The screen door is a door provided in the transport room for inspection.

6. The ion implantation apparatus according to claim 2, wherein: The ion implantation apparatus further comprises a door locking and unlocking unit, which locks and unlocks the shield door. When the X-ray irradiator irradiates X-rays, the control unit locks the shielding door through the door locking and unlocking unit.

7. The ion implantation apparatus according to claim 1, wherein: When a person enters a predetermined area set around the transport room, the control unit determines that the predetermined situation has been detected and stops the X-ray irradiator from irradiating X-rays or disables the X-ray irradiator from being activated.

8. The ion implantation apparatus according to any one of claims 1 to 7, wherein: The ion implantation apparatus includes an implantation chamber for implanting ions into the substrate. When the control unit stops irradiating X-rays from the X-ray irradiator, the control unit stops conveying the substrate from the conveying chamber to the implantation chamber.

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