Fault pulse compensation system and compensation method of ion implanter

Abstract

The invention discloses a fault pulse compensation system of an ion implanter. The fault pulse compensation system comprises a scanning motor module, a coding processing module, an IO control module and a logic circuit module, the scanning motor module is used for driving the wafer target table to move and feeding back a position signal; the coding processing module is used for processing the position signal and generating control logic; the IO control module is used for distinguishing power supply fault signals; and the logic circuit module is used for realizing hardware-level fault response. The invention also discloses a compensation method which comprises the following steps: when a fault pulse is detected, latching a current wafer position and triggering an edge signal to turn off an arc voltage power supply; when the wafer moves to the restriking position, the beam is cut off; or multiple times of refilling: firstly, setting a leading-out bias voltage; when the wafer moves to a restriking starting position, the beam is released; and the beam is cut off when the wafer moves to the restriking ending position. The wafer injection method has the advantages of improving the uniformity and yield of wafer injection and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ion implanters, in particular to a fault pulse compensation system and method for ion implanters. BACKGROUND

[0002] An ion implanter is a key equipment for semiconductor manufacturing, which accelerates charged ions and implants them into semiconductor materials to change their electrical properties. During the ion implantation process, transient changes in high-voltage power supply or external electromagnetic interference can cause Glitch in the power supply, especially for some low-energy beam Glitch with higher frequency. Any slight deviation or instability will have a significant impact on the quality and performance of the final product.

[0003] The existing Glitch compensation injection system more or less has the following technical problems: The existing Glitch compensation injection system can only detect that Glitch has occurred and cannot distinguish which power supply problem has occurred, the alarm information is not clear, and the problem cannot be quickly located; Since the existing Glitch compensation system only contains one light signal for turning off the extraction power supply, it cannot implement more than one compensation; After the existing Glitch compensation system occurs once, Glitch occurs again during the compensation process, triggering secondary Glitch, and the existing hardware system and compensation logic cannot perform compensation injection, affecting product safety; The normal state of the optical fiber communication signal of the existing Glitch compensation system is extinguished, and it emits light when Glitch occurs. If the optical fiber is broken, it will cause subsequent alarms and cannot trigger Glitch, which has the risk of scrapping the product and affects product safety; The existing light signal for turning off the high-voltage power supply can only control the switch, and there is no return signal. If the control signal is faulty, it cannot be alarmed in advance, causing wafer scrapping and affecting product safety; The existing Glitch compensation system turns off the power supply by the Glitch controller, then sends a light signal to the dose controller, and the dose controller records the position. In this way, the power supply is turned off and the position is recorded in two systems, which causes an unstable time difference between the position of the turned-off beam and the actual recorded position, resulting in unstable compensation uniformity and the risk of product scrapping. SUMMARY

[0004] In view of the technical problems existing in the prior art, the present application provides a fault pulse compensation system and method for ion implanters to improve wafer injection uniformity and yield.

[0005] To solve the above technical problems, the technical solution provided by the present application is: A fault pulse compensation system of an ion implanter, comprising a scanning motor module, an encoding processing module, an IO control module and a logic circuit module; The scanning motor module is configured to drive a wafer target table to move and feed back a position signal. The encoding processing module is configured to process the position signal and generate a control logic. The IO control module is configured to distinguish a plurality of power supply fault signals. The logic circuit module is configured to implement a hardware-level fault response.

[0006] Preferably, the scanning motor module comprises a Yscan motor configured to drive a wafer target table to move and a Yscan grating ruler configured to detect a position signal of the wafer target table.

[0007] Preferably, the encoding processing module comprises a Yscan Encoder module, a position latch module, a Glitch Enable module and a comparison output module. The position latch module is configured to receive a Glitch signal output from the logic circuit module and record a position. The Glitch Enable module is configured to receive a position signal Yscan Encoder from the scanning motor module, compare the Yscan Encoder with a Glitch Enable Position value and output a Glitch Enable level. The comparison output module is configured to compare the Yscan Encoder with a Glitch compensation position, and output a level signal to the logic circuit module to control a high voltage power supply when the actual position of the Yscan Encoder is equal to the Glitch compensation position.

[0008] Preferably, the IO control module comprises a first IO control unit and a second IO control unit. The first IO control unit is configured to distinguish a power supply Glitch signal independently. The second IO control module is configured to simulate a Glitch signal to detect a Glitch detection system.

[0009] Preferably, the first IO control unit comprises a plurality of optical signal input channels, each of which corresponds to a power supply fault state.

[0010] Preferably, the logic circuit module comprises a fiber receiver, a logic processor, an edge trigger, an AND gate, a first fiber transmitter and a second fiber transmitter. The fiber receiver is used for receiving external Glitch optical signals, and transmitting each signal to the IO control module respectively, thereby distinguishing abnormal power supply. The logic processor is used for making logical judgment on Glitch monitoring signals of all power supplies; when the fiber changes from bright to dark, a level change is generated, which is fed back to the AND gate; if Glitch Enable is also in a triggering state, the position is recorded by the encoding processing module. The edge trigger is used for outputting a state and feeding back to the IO control module, thereby monitoring ARC closing. The first fiber transmitter is used for receiving an output signal from the edge trigger, triggering the ARC power supply to be closed through the fiber, thereby cutting off the beam current. The second fiber transmitter is used for receiving a triggering signal from the encoding processing module, triggering the bias voltage of the extraction power supply to be set through the fiber, thereby cutting off the beam current.

[0011] The application further discloses a compensation method of the fault pulse compensation system based on the ion implanter. Each power supply state is monitored in real time through multiple independent optical fiber signals. When a fault pulse is detected, the current wafer position and the edge signal for triggering the ARC power supply to be closed are latched. One-time compensation is performed: when the wafer moves to the compensation position, the ARC power supply is closed through the first fiber transmitter, thereby cutting off the beam current. Or multiple-time compensation is performed: before the wafer starts to be implanted, the second fiber transmitter sets the extraction bias voltage; when the wafer moves to the compensation start position, the second fiber transmitter is extinguished, thereby releasing the beam current; when the wafer moves to the compensation end position, the first fiber transmitter is turned on, thereby cutting off the beam current, and the two-time compensation is completed.

[0012] Preferably, when the fiber is extinguished, the position is recorded synchronously, and the first fiber transmitter is triggered to close the ARC power supply.

[0013] Preferably, in the multiple-time compensation process, when the actual Yscan position reaches the second interruption position, the second fiber transmitter is triggered synchronously, the extraction voltage setting value is restored, thereby restoring the beam current; wherein the second interruption position is the Yscan position when the two-time Glitch occurs.

[0014] Preferably, in the multiple Glitch compensation process, the first fiber transmitter is triggered synchronously when the position of the actual Yscan reaches the first interrupt position, the arc voltage power is turned off, and then the beam current is turned off, thereby completing the multiple Glitch compensation; wherein the first interrupt position is the position of Yscan when a Glitch occurs.

[0015] Compared with the prior art, the present application has the following advantages: The present application uses pure hardware triggering to uniformly perform the operations of turning off the beam current and recording the position, the response time of turning off is in the nanosecond level, the response is more timely, the consistency of turning off the beam current and recording the position is ensured, thereby the uniformity of the product is ensured, and the yield of the product is improved (the original system turns off the beam current by using the high-voltage power supply, and the position is collected by using the dose system).

[0016] The present application adds a fiber receiver and a signal collection system to realize a multi-channel independent monitoring system, can distinguish the channel signals, and can independently monitor each signal (the original system only has one signal and only knows that a Glitch occurs, but cannot determine which power supply Glitch).

[0017] The present application compensates by turning off the arc voltage power supply and setting the extraction bias voltage, and the beam current is turned off more timely (the original system can only compensate by turning off the extraction power supply).

[0018] The present application adds an internal logic circuit to realize the function of turning off the beam current after the fiber signal monitoring and the Glitch Enable signal are triggered synchronously; when the fiber is extinguished, the position is recorded synchronously and the fiber transmitter is triggered to turn off the arc voltage power supply (turn off the beam current); when the fiber is extinguished, the position of Yscan is recorded synchronously and the fiber transmitter is controlled to turn off the arc voltage power supply; in the compensation process, when the position of the actual Yscan reaches the interrupt position 2, the fiber transmitter is triggered synchronously, the extraction voltage setting value is restored, and then the beam current is restored; when the position of the actual Yscan reaches the interrupt position 1, the first fiber transmitter is triggered synchronously, the arc voltage power supply is turned off, and then the beam current is turned off, thereby completing the multiple Glitch compensation. The Glitch signal of the present application is in the light-emitting state and is extinguished when a Glitch occurs, since the Glitch light signal is in the constant light state, the fiber anomaly can be detected in advance, and the product safety is increased (the normal state of the Glitch signal in the original scheme is extinguished, and the Glitch is light-emitting); the present application adds the feedback signal of the ARC fiber (the original scheme has no monitoring of the beam current turning off signal). BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The block structure diagram of the fault pulse compensation system of the present application in the embodiment. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 As shown, the fault pulse compensation system for the ion implanter provided in this embodiment of the invention includes a scanning motor module, an encoding processing module, an I / O control module, and a logic circuit module. The scanning motor module includes a Yscan motor and a Yscan grating ruler. The Yscan motor drives the target stage that electrostatically adsorbs the wafer to move, and the Yscan grating ruler is used for high-precision position feedback. During ion implantation, the scanning speed of the Yscan motor is calculated by the dose, current intensity, implantation angle and azimuth. By moving the YSCAN scanning motor at a constant speed, a specific dose of ion implantation is achieved. The encoding processing module includes a Yscan Encoder module, a position latch module, a Glitch Enable module, and a comparison output module; The position latch module receives the Glitch signal from the AND gate output of the logic circuit module and records the position. The Glitch Enable module receives the position signal from the Yscan grating ruler, compares the Yscan Encoder with the set Glitch Enable Position value, and outputs the Glitch Enable level to control the triggering of the AND gate in the logic circuit module. The comparison output module compares the Yscan Encoder with the set Glitch replacement position. When the actual position of the Yscan Encoder is equal to the Glitch replacement position, it outputs a level signal to the logic circuit module to control the high voltage power supply. Specifically, the IO control module includes a first IO control unit (in) and a second IO control module (out). The second IO control module (out) contains an out signal to the fiber optic transmitter, simulating a Glitch signal, which is used to detect the quality of the Glitch detection system. The first IO control module (in) contains 7 independent optical signal inputs to the IO control module, used to independently distinguish the power supply Glitch signal.

[0022] Specifically, the logic circuit module includes a fiber optic receiver, a logic processor, an edge-triggered flip-flop, an AND gate, and two fiber optic transmitters; The fiber optic receiver receives external Glitch optical signals and transmits each signal individually to the first IO control unit (in), so that the host computer can distinguish abnormal power sources. The logic processor is for logic judgment of Glitch monitoring signals of all power supplies, and a level change is generated as soon as the optical fiber changes from bright to dark, the change is fed back to an AND gate, and the position recording module of the encoding processing module records the position if Glitch Enable is also in a triggering state. At the same time of recording the position, the level signal triggers an edge trigger, the optical fiber transmitter is closed to shut off the arc voltage power supply, and then the beam current is cut off, and the wafer is re-injected. The edge trigger outputs a state and feeds back to a first IO control unit (in) for monitoring of the ARC closing; The first optical fiber transmitter (close arc voltage power supply) receives an output signal from the edge trigger, and after triggering, the arc voltage power supply is closed through the optical fiber, and then the beam current is cut off; The second optical fiber transmitter (set the extraction bias voltage) receives a trigger signal from the comparison output module of the encoding processing module, and after triggering, the extraction bias voltage of the extraction power supply is set through the optical fiber, and then the beam current is cut off.

[0023] The application uses pure hardware triggering to uniformly perform the operations of closing the beam current and recording the position, the shutdown response time is in the nanosecond level, the response is more timely, the consistency of closing the beam current and recording the position is ensured, and then the uniformity of the product is ensured, and then the yield of the product is improved (the original system closes the beam current by using the high-voltage power supply, and the position is collected by using the dose system).

[0024] The application adds an optical fiber receiver and a signal collection system to realize a multi-path independent monitoring system, distinguish channel signals, and independently monitor each signal (the original system only has one signal and only knows that Glitch occurs, but cannot determine which power supply Glitch occurs).

[0025] The application closes the arc voltage power supply and sets the extraction bias voltage to perform re-striking, and the beam current is closed more timely (the original system can only perform re-striking by closing the extraction power supply).

[0026] The application adds an internal logic circuit to realize the function of closing the beam current after the optical fiber signal monitoring and Glitch Enable signal are simultaneously triggered; when the optical fiber is detected to be extinguished, the position of Yscan is recorded synchronously and the optical fiber transmitter is triggered to close the arc voltage power supply (to close the beam current); when the optical fiber is detected to be extinguished, the position of Yscan is recorded synchronously and the optical fiber transmitter is triggered to close the arc voltage power supply; during re-striking, when the actual position of Yscan reaches the interruption position 2, the extraction voltage setting value is restored synchronously by triggering the optical fiber transmitter, and then the beam current is restored; when the actual position of Yscan reaches the interruption position 1, the first optical fiber transmitter is triggered synchronously to close the arc voltage power supply, and then the beam current is closed, and re-striking of multiple Glitch is completed. The Glitch signal is a light-emitting state, and is extinguished when Glitch occurs, since the Glitch light signal is a constant light state, the optical fiber abnormality can be detected in advance, and the product safety is increased (the original scheme Glitch signal normal state is extinguished, and emits light when Glitch occurs); the application adds the feedback signal of the ARC optical fiber (the original scheme has no monitoring of the beam-off signal); The application further discloses a compensation method of the fault pulse compensation system based on the ion implanter. Each power supply state is monitored in real time through multiple independent optical fiber signals; When the fault pulse is detected, the current wafer position and the trigger edge signal are latched to turn off the arc voltage power supply; One-time compensation is performed: when the wafer moves to the compensation position, the ARC power supply is turned off through the first optical fiber transmitter, and then the beam is cut off; Or multiple compensation is performed: before the wafer starts to be implanted, the second optical fiber transmitter sets the extraction bias voltage, when the wafer moves to the compensation start position, the second optical fiber transmitter is extinguished, and then the beam is released, when the wafer moves to the compensation end position, the first optical fiber transmitter is turned on, and then the beam is cut off, and the two-time compensation is completed.

[0027] In the multiple compensation process, when the actual Yscan position reaches the second interruption position, the second optical fiber transmitter is triggered synchronously, the extraction voltage setting value is restored, and then the beam is restored; wherein the second interruption position is the position of Yscan when the two-time Glitch occurs. When the actual Yscan position reaches the first interruption position, the first optical fiber transmitter is triggered synchronously, the arc voltage power supply is turned off, and then the beam is turned off, and the multiple Glitch compensation is completed; wherein the first interruption position is the position of Yscan when the one-time Glitch occurs.

[0028] Note: the interruption position of Yscan when the three-time Glitch occurs is updated to the second interruption position, no matter how many times Glitch occurs, only the second interruption position is updated, and the first interruption position 1 is always unchanged.

[0029] The multiple Glitch compensation technology reduces the wafer scrap rate, the scheme not only solves the technical limitation of single-time compensation, but also reconstructs the fault tolerance system of the ion implantation process from the economic point of view; in order to realize the multiple Glitch compensation technology, the hardware trigger and compensation are used, multiple compensation can be realized, compared with the previous position trigger, the multiple compensation is more accurate, the uniformity after the compensation is completed is consistent with that of normal implantation, and the product yield is improved.

[0030] The application can distinguish the state of each power supply by increasing the optical fiber receiver and signal acquisition system; the two-way independent control optical signal can be realized by upgrading the hardware system, the simultaneous opening and closing of the two power supplies is realized, and then more than one time of re-shooting is achieved; the hardware system and logic of the application can realize twice re-shooting, if three times of Glitch occurs again during the twice re-shooting, the application mode can still re-shoot, and the re-shooting can be carried out infinitely until the re-shooting is completed; by modifying the hardware part, the normal state is constant and the abnormal state is extinguished, so if the optical fiber is broken, it can be found under the condition of meeting the Glitch use; by increasing the feedback signal, the feedback of the optical fiber bright and dark is realized, and the safety of the product is improved; by optimizing the logic circuit and processing logic of the dose controller, the dose controller is responsible for the closing of the high-voltage power supply and the recording of the interruption position when Glitch occurs.

[0031] The above is only the preferred embodiment of the application, the protection scope of the application is not limited to the above-mentioned embodiments, and any technical scheme belonging to the idea of the application falls within the protection scope of the application. It should be pointed out that, for ordinary skilled in the art, some improvements and decorations without departing from the principle of the application should be considered as the protection scope of the application.

Claims

1. A fault pulse compensation system for an ion implanter, characterized in that, It includes a scanning motor module, an encoding processing module, an I / O control module, and a logic circuit module; The scanning motor module is used to drive the wafer stage to move and provide feedback position signals; The encoding processing module is used to process position signals and generate control logic; The IO control module is used to distinguish between multiple power supply fault signals; The logic circuit module is used to implement hardware-level fault response.

2. The fault pulse compensation system for the ion implanter according to claim 1, characterized in that, The scanning motor module includes a Yscan motor and a Yscan grating ruler. The Yscan motor is used to drive the target stage that electrostatically attaches the wafer to move; the Yscan grating ruler is used to detect the position signal of the target stage.

3. The fault pulse compensation system for the ion implanter according to claim 1 or 2, characterized in that, The encoding processing module includes a Yscan Encoder module, a position latch module, a Glitch Enable module, and a comparison output module; The position latch module is used to receive the Glitch signal output from the logic circuit module and record the position. The Glitch Enable module is used to receive the position signal Yscan Encoder from the scanning motor module, compare the Yscan Encoder with the set Glitch Enable Position value, and output the Glitch Enable level. The comparison output module is used to compare the Yscan Encoder with the set Glitch re-printing position; when the actual position of the Yscan Encoder is equal to the set Glitch re-printing position, it outputs a level signal to the logic circuit module to control the high-voltage power supply.

4. The fault pulse compensation system for the ion implanter according to claim 1 or 2, characterized in that, The IO control module includes a first IO control unit and a second IO control unit; The first I / O control unit is used to independently distinguish the power supply Glitch signal; The second IO control module is used to simulate Glitch signals to detect the quality of the Glitch detection system.

5. The fault pulse compensation system for the ion implanter according to claim 4, characterized in that, The first IO control unit includes multiple optical signal input channels, each channel corresponding to monitor the fault status of a power supply; the fault pulse signal is always on under normal conditions and turns off when a fault occurs.

6. The fault pulse compensation system for the ion implanter according to claim 1 or 2, characterized in that, The logic circuit module includes an optical fiber receiver, a logic processor, an edge trigger, an AND gate, a first optical fiber transmitter, and a second optical fiber transmitter. The fiber optic receiver is used to receive external Glitch optical signals and transmit each signal separately to the IO control module to distinguish abnormal power sources. The logic processor is used to make logical judgments on the Glitch monitoring signals of all power supplies; when the optical fiber changes from bright to dark, a level change will be generated, and this change will be fed back to the AND gate. If Glitch Enable is also in the triggered state, the encoding processing module will record the position. The edge trigger is used to output the status and feed it back to the IO control module for monitoring ARC shutdown; The first fiber optic transmitter is used to receive the output signal from the edge trigger, and after triggering, it shuts off the arc voltage power supply through the fiber optic cable, thereby cutting off the beam current; The second fiber optic transmitter is used to receive a trigger signal from the encoding processing module. After triggering, the bias voltage of the power supply is set through the fiber optic cable, thereby cutting off the beam current.

7. A compensation method for a fault pulse compensation system based on the ion implanter of claim 6, characterized in that, Including the following steps: The status of each power supply is monitored in real time through multiple independent fiber optic signals. When a fault pulse is detected, the current wafer position and trigger edge signal are latched to shut down the arc voltage power supply. Perform a re-firing: When the wafer moves to the re-firing position, the ARC power is turned off through the first fiber transmitter, thereby cutting off the beam current; Alternatively, multiple re-firing can be performed: Before wafer injection begins, the second fiber transmitter is set to output a bias voltage. When the wafer moves to the re-firing start position, the second fiber transmitter is turned off, thereby releasing the beam current. When the wafer moves to the re-firing end position, the first fiber transmitter is turned on, thereby cutting off the beam current and completing the second re-firing.

8. The compensation method according to claim 7, characterized in that, When the optical fiber is detected to be out of service, the synchronous recording position is activated and the first optical fiber transmitter is triggered to shut down the arc voltage power supply.

9. The compensation method according to claim 7, characterized in that, During multiple re-firing processes, when the actual Yscan position is detected to reach the second interruption position, the second fiber transmitter is synchronously triggered to restore the output voltage setting value, thereby restoring the beam current; where the second interruption position is the position of the Yscan when the secondary Glitch occurs.

10. The compensation method according to claim 7, characterized in that, During multiple re-laying processes, when the actual Yscan position is detected to reach the first interruption position, the first fiber transmitter is synchronously triggered to shut down the arc voltage power supply, thereby shutting down the beam and completing multiple Glitch re-laying processes; where the first interruption position is the position of the Yscan when a Glitch occurs.

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