Ion implanter

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 implanter. [Background technology]

[0002] For example, as shown in Patent Document 1, there is an ion implantation apparatus equipped with a crystal axis measurement device that measures the direction of the crystal axis of a substrate by irradiating the substrate with X-rays before ion implantation. With this apparatus, it is possible to implant ions into a substrate while taking channeling into consideration by adjusting the irradiation direction of the ion beam with respect to the substrate based on the measurement results of the crystal axis measurement device.

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

[0004] [Patent Document 1] Patent Publication No. 2021-120944 Summary of the Invention [Problem to be solved by the invention]

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

[0006] That is, a main object of the present invention is to provide an ion implantation apparatus in which X-ray irradiation is reliably stopped when an operator sets a substrate or when maintenance is performed. [Means for solving the problem]

[0007] [1] The ion implantation apparatus according to the present invention comprises: An ion implantation apparatus for implanting ions into a substrate, comprising: a transfer chamber in which the substrate is transferred between the transfer chamber and the outside; an X-ray irradiator disposed in the transfer chamber and configured to irradiate the substrate with X-rays before ion implantation; and a control unit that stops the X-ray irradiation by the X-ray irradiator or disables the activation of the X-ray irradiator when a predetermined situation is detected in the transfer chamber or outside the transfer chamber.

[0008] In the ion implantation apparatus configured as described above, when the control unit detects a predetermined situation, it is possible to stop the X-ray irradiation by the X-ray irradiator or disable the activation of the X-ray irradiator. That is, the ion implantation apparatus of the present invention automatically and reliably stops the X-ray irradiation in a predetermined situation.

[0009] [2] In the ion implantation apparatus according to the present invention, the transfer chamber may include at least one shielding door that blocks X-rays from the X-ray irradiator, and the control unit may determine that the predetermined situation is a state in which the shielding door is open or a state in which the shielding door is unlocked, and may stop the X-ray irradiation by the X-ray irradiator or disable activation of the X-ray irradiator. With this configuration, when the shielding door is opened or unlocked, for example, when an operator supplies a substrate or performs maintenance, the X-ray irradiation is automatically stopped. Furthermore, even if the shielding door is left open or unlocked after the operator has finished their work, X-ray irradiation will not begin, preventing X-rays from leaking outside the transport chamber from the space opened by the shielding door.

[0010] [3] The ion implantation apparatus according to the present invention may include a door sensor that detects whether the shielding door is open or closed. As a door sensor for detecting the opening of a shielding door, for example, a so-called safety door switch in which the switch body and the operating part for operating the body are separate, a so-called limit switch in which the door acts as an actuator to operate the switch, or a non-contact proximity sensor that operates the switch contacts using magnetism or the like can be selected.

[0011] [4] The shielding door is preferably provided on a transfer path along which the substrate is transferred from the outside to the transfer chamber. With this configuration, X-ray irradiation can be stopped when the shielding door is opened to transport the substrate. Also, if a shielding door on a transport path that is frequently opened is not properly closed, X-ray irradiation will not start.

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

[0013] [6] The ion implantation apparatus according to the present invention may further include a door locking / unlocking unit that locks and unlocks 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, which prevents X-rays from leaking outside the transfer chamber, ensuring a higher level of safety for the ion implantation apparatus.

[0014] [7] When a person has entered a predetermined area set around the transport chamber, the control unit may detect the predetermined situation and stop the X-ray irradiation by the X-ray irradiator or disable the activation of the X-ray irradiator. With this configuration, for example, the irradiation of X-rays can be stopped at the stage when an operator approaches the ion implantation apparatus, that is, at a stage before the operator comes into contact with the apparatus.

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

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

[0017] [Figure 1] 1 is a plan view schematically showing the structure of an ion implantation apparatus (with a first shielding door closed) according to an embodiment of the present invention; [Figure 2] FIG. 2 is a plan view schematically showing the structure of the ion implantation apparatus according to the embodiment (with the first shielding door open); [Figure 3] FIG. 2 is a perspective view showing the ion implantation apparatus of the embodiment. [Figure 4] FIG. 10 is a plan view schematically showing the structure of the ion implantation apparatus of the second embodiment (with the second shielding door open); [Figure 5] FIG. 10 is a perspective view showing an ion implantation apparatus according to a second modification of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] [First embodiment] An embodiment of an ion implantation apparatus according to the present invention will now 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, and performs ion implantation by irradiating an ion beam IB onto a substrate S in an implantation chamber IC that has been evacuated to a high vacuum environment as shown in Figures 1 and 2. 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, such as a silicon wafer, a silicon carbide wafer, etc. The substrate S may also be a base material having a single crystal film of silicon, silicon carbide, etc. formed on the surface thereof.

[0021] 1 to 3, the ion implantation apparatus 100 includes an implantation chamber IC in which ions are implanted into the substrate S, and a transfer chamber TC located adjacent to the implantation chamber IC and used to transfer the substrate S to and from the outside. The transfer chamber TC is placed under atmospheric pressure. The ion implantation apparatus 100 further includes two load lock chambers LLC located between the implantation chamber IC and the transfer chamber TC, the interior of which can be switched between high vacuum and atmospheric pressure.

[0022] The implantation chamber IC and the transfer chamber TC are connected via the load lock chamber LLC so as to be able to transfer the substrate S, forming a so-called end station. Note that the implantation chamber IC and the transfer chamber TC do not necessarily have to be adjacent to each other, as long as they are connected by a transfer path for the substrate S that passes through the load lock chamber LLC.

[0023] As shown in Figures 1 and 2, the transport chamber TC is equipped with a transport section (not shown) arranged along a predetermined transport path for the substrate S, and an aligner 1 arranged on the transport path that positions the substrate S based on an orientation flat or notch formed on the substrate S being transported.

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

[0025] The substrate setting section 2a is a place for supplying substrates S to the ion implantation device 100. The substrate setting section 2a here is a place where an operator sets a case (a so-called substrate cassette SC) that stores a plurality of substrates S.

[0026] The transfer unit of this embodiment also transfers out the substrate S after ion implantation in which ions have been implanted in the implantation chamber IC. Specifically, the transfer unit transfers the substrate S, into which ions have been implanted in the implantation chamber IC, to the substrate recovery unit 2b provided in the transfer chamber TC via the load lock chamber LLC.

[0027] The substrate recovery unit 2b is a place where an operator recovers the cassette SC containing the ion-implanted substrates S. In this embodiment, the substrate setting unit 2a and the substrate recovery unit 2b are provided in different locations, but they may also be provided in a common location.

[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 (here, the crystal orientation) of the substrate S before ion implantation.

[0029] The crystal structure analysis unit 3 of this embodiment is arranged in the transfer chamber TC as shown in Figures 1 and 2, 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.

[0030] The crystal structure analysis unit 3 includes an X-ray irradiator 31 that irradiates the processing surface of the substrate S with X-rays, an X-ray detector 32 that detects the X-rays reflected by the processing 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 described above.

[0031] The crystal structure analysis unit 3 calculates the crystal orientation by irradiating X-rays onto the substrate S, which has been aligned with an orientation flat or a notch by the aligner 1. Then, based on the 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 that of an apparatus commonly known as an X-ray diffraction apparatus (XRD), and the X-ray irradiator 31, X-ray detector 32, and analyzer 33 can employ components or configurations commonly used in X-ray diffraction apparatus (XRD).

[0033] The analyzer 33 is physically composed of a CPU, memory, A / D converter, etc., and performs its functions by the CPU and peripheral devices working together in accordance with a program stored in a specified area of ​​the memory.

[0034] 3. Safety Measures However, in consideration of safety regarding X-rays, it is necessary to ensure that the irradiation of X-rays from the X-ray irradiator 31 is stopped while an operator is loading a cassette SC containing substrates S before ion implantation into the transfer chamber TC, and while an operator is unloading a cassette SC containing substrates S after ion implantation from the transfer chamber TC. Furthermore, in the ion implantation apparatus 100, it is necessary to prevent the X-rays irradiated from the X-ray irradiator 31 from leaking outside the transfer chamber TC. Therefore, the ion implantation apparatus 100 of this embodiment is provided with a shielding structure that physically blocks X-rays that would otherwise leak outside the apparatus, and a function that reliably stops X-ray irradiation when an operator loads or unloads a cassette SC or when performing maintenance work inside the transfer chamber TC. These will be described below.

[0035] 3-1.Transportation Room TC Shielding Wall 4 First, the shielding wall 4 that forms the transfer chamber TC is configured to have the function of blocking X-rays. This 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.

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

[0037] The configuration (number and arrangement) of the shielding walls 4 is not limited to the above, and may be any configuration that prevents X-rays generated from the X-ray irradiator 31 from leaking outside the ion implantation apparatus 100.

[0038] 3-2. First Shielding Door 5 As shown in FIGS. 1 to 3 , the shielding wall 4 is provided with a first shielding door 5 for opening and closing the transfer chamber TC. The first shielding door 5 is a plate-shaped door made of an X-ray shielding material, and in this case is a hinged door. In this embodiment, the shielding wall 4 is provided with two first shielding doors 5, and these two first shielding doors 5 are arranged in front of the substrate setting unit 2a and the substrate recovery unit 2b, respectively. When the first shielding door 5 is opened, an operator can set a cassette SC in the substrate setting unit 2a or recover a cassette SC from the substrate recovery unit 2b. Note that the number and arrangement of the first shielding doors 5 are not limited to those described above.

[0039] The ion implantation apparatus 100 of this embodiment includes a first door sensor 51 that detects the open / closed state of the first shielding door 5. When the first shielding door 5 is in an open state, the first door sensor 51 outputs, for example, a detection signal indicating that the open state has been detected to a control unit 6 (described later). The first door sensor 51 of this embodiment is a safety door switch that includes a main body 51a fixed to the opening of the first shielding door 5 and an operation unit 51b fixed to the inside of the first shielding door 5.

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

[0041] The first door sensor 51 may be a limit switch in which the door acts as an actuator to operate the switch, or a non-contact proximity sensor in which the contacts of the switch are operated by magnetism, etc. The first door sensor 51 may also be a camera, etc.

[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 means, 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 startup 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 startup 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. 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 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 the crystal structure analysis unit 3 is irradiated with X-rays and the case where it is not irradiated with X-rays.

[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 collecting the substrate S, the control unit 6 stops the irradiation of X-rays from the X-ray irradiator 31. Then, 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 collecting the substrate S, the control unit 6 disables the activation of the X-ray irradiator 31. Then, 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 this embodiment configured as described above, in a predetermined situation (here, the situation where the first shielding door 5 is open), X-rays are not irradiated by interlock control, so that an operator performing operations 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 so that an operator can perform maintenance, inspection, etc. inside the transfer chamber TC. The second shielding door 7 is configured so that an operator can access the equipment provided inside the transfer chamber TC from outside the transfer chamber TC through the opened second shielding door 7. The second shielding door 7 here is disposed at a position where the operator can access the X-ray irradiator 31 or the X-ray detector 32. Note that the second shielding door 7 here may be an inspection door provided inside the transfer chamber TC, or may be disposed so that equipment other than the crystal structure analysis unit 3 can be accessed through the second shielding door 7.

[0052] When this second shielding door 7 is opened, an operator can inspect, maintain, or repair the equipment installed inside the transfer chamber TC. When this second shielding door 7 is open, the crystal structure analysis unit 3 is interlocked, so that the generation of X-rays from the X-ray irradiator 31 is reliably stopped. Therefore, an operator can safely perform inspections and other tasks.

[0053] [First Modification] As shown in FIG. 4 , 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 human 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 disable the activation of the X-ray irradiator 31 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 attached to the outside of the shielding wall 4. The human detection sensor 72 may be another infrared sensor, or may be an ultrasonic sensor, a microwave sensor, or a sound sensor. The human detection sensor may also be disposed near the first shielding door 5.

[0054] With this configuration, the irradiation of X-rays can be stopped by interlock control when the worker approaches the second shielding door 7, that is, at an earlier stage than the worker opens the second shielding door 7.

[0055] [Second Modification] 5, the ion implantation apparatus 100 may include a door locking / unlocking unit 53 that locks and unlocks the first shielding door 5. The door locking / unlocking unit 53 may also lock and unlock the second shielding door 7. The door locking / unlocking unit 53 in this modification is composed of a locking main body 53a fixed to the shielding wall 4 and a key 53b. The first shielding door 5 is unlocked when an operator inserts the key 53b into the opening of the locking main body 53a. The first shielding door 5 is locked when an operator pulls out the key 53b from the opening of the locking main body 53a.

[0056] 5 shows a configuration in which a door locking / unlocking unit 53 is provided instead of the first door sensor, but the door locking / unlocking unit 53 may be provided in combination with the first door sensor. Also, the first door sensor or the second door sensor may have the function of locking / unlocking the first shielding door 5 or the second shielding door 7. In this modified example, the control unit 6 detects the state in which the door locking / unlocking unit 53 is unlocked (not locked) as a specified situation in addition to (or instead of) the state in which the first shielding door 5 or the second shielding door 7 is open.

[0057] In this modified example, for example, when an operator unlocks the locked first shielding door 5, the control unit 6 performs interlock control to stop the emission of X-rays from the X-ray irradiator 31. In the unlocked state, even if the operator opens or closes the first shielding door 5, the control unit 6 keeps the door locked, and when the first shielding door 5 is locked thereafter, the control unit 6 releases the interlock. In this way, the interlock is activated before the operator actually opens the first shielding door 5. Therefore, it is possible to reliably stop the emission of X-rays from the X-ray irradiator 31 when the operator loads or unloads a cassette SC, for example.

[0058] Furthermore, the control unit 6 of this modified example may lock the first shielding door 5 or the second shielding door 7 using the door locking / unlocking unit 53 while 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 during X-ray irradiation.

[0059] The ion implantation apparatus 100 is equipped with a plurality of first shielding doors 5 and second shielding doors 7 having different uses, and the control unit 6 may detect that at least one of these shielding doors 5, 7 is open or unlocked as a predetermined situation.

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

[0061] In addition, various modifications and combinations of the embodiments may be made as long as they do not go against the spirit of the present invention. [Explanation of symbols]

[0062] IB: Ion Beam S... Substrate SC... Substrate Cassette 100 Ion implantation equipment 1. Aligner 2a Circuit board setting section 2b: Substrate recovery section 3...Crystal structure analysis department 31...X-ray irradiator 32 X-ray detector 4...shielding wall 5. First Shield Door 51 First door sensor 6 Control section 7. Second Shielding Door 71 Second door sensor IC...Injection chamber TC Transfer Room LLC···Load Lock Chamber

Claims

1. An ion implantation apparatus for implanting ions into a substrate, comprising: a transfer chamber in which the substrate is transferred between the transfer chamber and the outside; an X-ray irradiator disposed in the transfer chamber and configured to irradiate the substrate with X-rays before ion implantation; a control unit that stops the X-ray irradiation by the X-ray irradiator or disables activation of the X-ray irradiator when a predetermined situation is detected in the transfer chamber or outside the transfer chamber.

2. the transport chamber includes at least one shielding door that blocks X-rays from the X-ray irradiator; 2. The ion implantation apparatus according to claim 1, wherein the control unit determines that the predetermined situation is a state in which the shielding door is open or a state in which the shielding door is unlocked, and stops the X-ray irradiation by the X-ray irradiator or disables activation of the X-ray irradiator.

3. 3. The ion implantation apparatus according to claim 2, further comprising a door sensor for detecting whether the shielding door is open or closed.

4. 3. The ion implantation apparatus according to claim 2, wherein the shielding door is provided on a transfer path along which the substrate is transferred from the outside to the transfer chamber.

5. 3. The ion implantation apparatus according to claim 2, wherein the shielding door is an inspection door provided in the transfer chamber.

6. Further provided is a door locking / unlocking unit that locks and unlocks the shielding door, 3. The ion implantation apparatus according to claim 2, wherein the control unit causes the door locking / unlocking unit to lock the shielding door when the X-ray irradiator is irradiating X-rays.

7. 2. The ion implantation apparatus according to claim 1, wherein the control unit detects a situation in which a person has entered a predetermined area set around the transfer chamber, and stops the X-ray irradiation by the X-ray irradiator or disables activation of the X-ray irradiator.

8. an implantation chamber in which ions are implanted into the substrate; 8. The ion implantation apparatus according to claim 1, wherein the control unit stops transporting the substrate from the transport chamber to the implantation chamber when the control unit stops irradiating X-rays from the X-ray irradiator.

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