CN116053105A - Beam monitoring and response system for ion implanter - Google Patents

Abstract

The invention discloses a beam monitoring and responding system for an ion implanter, which comprises: the power supply enabling module is used for controlling whether the power supply is activated or not; the voltage setting and feedback module is used for setting a power supply voltage value and receiving a feedback value of the power supply voltage; the current feedback module is used for receiving a power supply current feedback value; the current amplitude overrun judging module is used for comparing the power supply current feedback value with a preset current threshold value and sending out a signal according to a comparison result; the current amplitude overrun duration judging module is used for comparing the current amplitude overrun duration with a preset duration threshold value and sending out a signal according to a comparison result; and the switch state output module is used for judging whether the beam current outputs a switch signal according to the current amplitude overrun judging module and the current amplitude overrun duration result. The invention has the advantages of simple structure, high intelligent degree, high judgment accuracy and the like.

Description

A Beam Monitoring and Response System for an Ion Implanter

technical field

The invention mainly relates to the technical field of semiconductor equipment manufacturing, in particular to an FPGA-based ion implanter beam current Glitch monitoring and response system.

Background technique

With the rapid development of integrated circuit manufacturing technology, higher and higher requirements are put forward for semiconductor process technology. Among them, semiconductor ion implantation is an important link in the production process of semiconductor chips, and the stability of the implantation beam intensity is one of the key factors determining the quality of ion implantation.

The factors that cause the instantaneous beam instability (Glitch) mainly include two aspects: on the one hand, due to a certain situation, the electric field in the acceleration channel is concentrated and the "corona" discharge occurs; on the other hand, due to the limitation of environmental conditions, the electrostatic adsorption effect field There is dust adsorption in the area, and high-pressure ignition occurs in severe cases. These factors will cause transient instability of the high voltage and affect the stability of the beam, resulting in uneven ion implantation, thereby affecting the quality of the process product. In addition to preventing the occurrence of such phenomena, it is necessary to adopt means to compensate for their impact.

Through the research, it is found that since the manipulation of the ion beam is realized by the electric field and the magnetic field, the stability of the beam can be judged by monitoring the high-voltage power supply. The traditional Glitch monitoring system has the following disadvantages:

One is to judge the stability of the beam current by monitoring the high-voltage power supply voltage, and there is a situation that the monitoring is not timely;

The second is that the monitoring system of the power supply adopts a series method, and the dose control system cannot distinguish the type of power supply where Glitch occurs, and can only deal with it uniformly;

The third is that the system does not have a self-test function, so it is impossible to know whether the function is normal;

Fourth, the determination of Glitch is performed by a software program, and the determination speed is relatively slow.

Contents of the invention

The technical problem to be solved by the present invention lies in: aiming at the technical problems existing in the prior art, the present invention provides a beam current monitoring and response system for an ion implanter with a simple structure, a high degree of intelligence, and a high determination accuracy.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A beam current monitoring and response system for an ion implanter, comprising:

A power enabling module, used to control whether the power is activated;

The voltage setting and feedback module is used to set the value of the power supply voltage and receive the feedback value of the power supply voltage;

A current feedback module, used to receive a power supply current feedback value;

The current amplitude overrun determination module is used to compare the power supply current feedback value with the preset current threshold, and send a signal according to the comparison result;

The current amplitude exceeding time duration determination module is used to compare the current amplitude exceeding time with the preset time threshold, and send a signal according to the comparison result;

The Glitch state output module is used to determine whether the beam current outputs a Glitch signal according to the result of the current amplitude exceeding the limit determination module and the current amplitude exceeding the time period.

As a further improvement of the system of the present invention: the power supply enabling module activates the power supply by controlling the on-off of the relay through a hardware circuit.

As a further improvement of the system of the present invention: the voltage setting and feedback module is used to set the value of the power supply voltage on the upper computer software according to the user's needs, and the upper computer receives the feedback value of the power supply voltage and displays it on the page show.

As a further improvement of the system of the present invention: the current feedback module is used to receive the feedback value of the current feedback channel, divide the collected real-time signal into two paths, one path is transmitted to the upper computer terminal as the feedback value display of the power supply current, and the other path It is passed to the current amplitude exceeding determination circuit, and compared with the preset current threshold.

As a further improvement of the system of the present invention: the current amplitude exceeding determination module is used to determine whether the real-time acquisition signal exceeds the threshold set by the user by using a hardware circuit.

As a further improvement of the system of the present invention: the current amplitude exceeding time length determination module is used to receive the level signal transmitted by the current amplitude exceeding determination module, and utilizes the hardware programmability of FPGA to determine whether the current amplitude exceeding time exceeds preset threshold.

As a further improvement of the system of the present invention: the Glitch state output module is used to output the Glitch state of the beam current in the form of an optical signal, and the trigger condition depends on the judgment of the current amplitude exceeding the limit judging circuit module and the current amplitude exceeding the time length judging module result.

As a further improvement of the system of the present invention: there are more than two beam current monitoring and response systems, and all the beam current monitoring and response systems are connected in series through optical fibers to realize simultaneous monitoring.

As a further improvement of the system of the present invention: one of the two or more beam monitoring and response systems is preset as the head system, and other beam monitoring and response systems except the head system send Glitch optical fiber signals, then the last one The upper-level system will receive this signal and continue to transmit the Glitch fiber optic signal to the upper level until it is transmitted to the head system.

As a further improvement of the system of the present invention: it also includes a function self-inspection module, and the function self-inspection module is used to detect whether the self-monitoring function is normal.

Compared with the prior art, the present invention has the advantages of:

1. The beam current monitoring and response system for ion implanters of the present invention is aimed at the defects of the existing Glitch monitoring and processing system for ion implanters that the monitoring is not timely, the signal is single, there is no self-test function and the judgment speed is relatively slow. The proposed FPGA-based beam Glitch monitoring and response system for ion implanters can monitor the system Glitch in real time and communicate with the dose control system through optical fiber signals. Complete the monitoring and processing of system glitch. The invention can cooperate with the dosage control system to complete the monitoring and processing of the system Glitch. The invention has the advantages of simple structure, high degree of intelligence, high judgment accuracy, etc. It can judge the stability of the beam current by monitoring the high-voltage power supply current, which is more accurate than monitoring the voltage.

2. The beam current monitoring and response system for ion implanters of the present invention can be used alone or in series through optical fibers. When applied to ion implanters, Glitch optical fiber signals of three types of power sources can be transmitted to the dose control system, three-way optical fibers The signal is connected in parallel with the dose control system, and the dose control system can identify different Glitch optical fiber signals to compensate for dose errors caused by different power supply Glitch. The invention can distinguish Glitch optical fiber signals of different types of power sources. The signals of different types of power sources are connected in parallel with the dose control system, and the dose control system can perform differential processing according to the occurrence of Glitch in different power sources.

3. The beam current monitoring and response system for an ion implanter of the present invention can check whether the function of the system itself is normal, in case the system does not process Glitch.

4. The beam current monitoring and response system for an ion implanter of the present invention can monitor the degree of change of the Glitch amplitude of the system through a hardware circuit, and use a voltage comparator to compare the real-time monitoring value with the set threshold to obtain high/low voltage. The level signal RAW_GLITCH is output to the FPGA, and the high/low level signal RAW_GLITCH can drive the clock of the FPGA through software programming FPGA to monitor the duration of Glitch occurrence. If the duration exceeds the limit, the FPGA can output the high/low level signal PROCESSED_GLITCH to drive the fiber to the dose. The control system transmits the Glitch generation signal, and the present invention can judge Glitch by hardware circuit, which is faster than software judgment.

5. The beam current monitoring and response system for an ion implanter of the present invention realizes real-time monitoring and processing of the high-voltage power supply current in the ion implanter based on hardware programmability, and determines the current amplitude and Whether the duration exceeds the limit, if it exceeds the limit, it will be regarded as Glitch. The hardware circuit quickly determines whether the current amplitude and duration exceed the limit. If it exceeds the limit, it will be regarded as Glitch. The system will cooperate with the dose control system in the ion implanter to complete the response to the beam current Glitch and compensate for the quality of the product caused by it. Influence. Compared with judging beam Glitch by software, the present invention utilizes hardware resources and uses FPGA hardware resources to greatly improve the processing performance of the system.

Description of drawings

Fig. 1 is a schematic diagram of the principle of the topology of the system of the present invention.

Fig. 2 is a schematic diagram of the principle of the present invention when applied in a specific application example.

Fig. 3 is a schematic diagram of the circuit principle of the present invention in a specific application example.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1 and Figure 2, the ion implanter beam current monitoring and response system of the present invention is a beam current Glitch monitoring and response system for an ion implanter based on FPGA, including: a power supply enabling module, a voltage setting Fixed and feedback module, current feedback module, current amplitude overrun determination module, current amplitude overrun duration determination module, Glitch state output module and functional self-test module; where:

The power enabling module is used to control whether the power is activated for use;

The voltage setting and feedback module is used to set the value of the power supply voltage according to the needs of users, and at the same time receive the feedback value of the power supply voltage;

The current feedback module is used to receive the feedback value of the power supply current;

The current amplitude exceeding determination module is used to compare the power supply current feedback value with the current threshold set by the user, and send a signal according to the comparison result;

The current amplitude exceeding time length judging module is used to compare the current amplitude exceeding time length with the time threshold set by the user, and send a signal according to the comparison result;

The Glitch state output module is used to determine whether the beam current outputs a Glitch signal according to the current amplitude exceeding determination module and the current amplitude exceeding time duration.

After adopting the above-mentioned technical solution of the present invention, the system of the present invention can monitor the beam current change of the ion implanter in real time, and transmit the real-time signal collected in the power supply current acquisition channel to the current amplitude exceeding limit determination circuit module and the current amplitude In the over-limit duration judging module, the user judges whether a glitch occurs in the beam current by using a threshold set by hardware programmability.

In a specific application example, the power enabling module activates the power supply by controlling the on and off of the relay through a hardware circuit.

In a specific application example, the voltage setting and feedback module can set the value of the power supply voltage on the host computer software according to the user's needs, and the host computer receives the feedback value of the power supply voltage and displays it on the page.

In a specific application example, the current feedback module receives the feedback value of the current feedback channel, and the collected real-time signal is divided into two channels, one is transmitted to the host computer as the feedback value display of the power supply current, and the other is transmitted to the current amplitude In the overrun judgment circuit, it is compared with the current threshold set by the user.

In a specific application example, the current amplitude exceeding determination module can use a hardware circuit to determine whether the real-time collected signal exceeds the threshold set by the user.

In a specific application example, the current amplitude overrun time determination module adopts an FPGA chip, which can receive the level signal transmitted by the current amplitude overrun determination module, and utilizes the hardware programmability of FPGA to determine the current amplitude overrun time period Whether the threshold set by the user is exceeded.

In a specific application example, the glitch state output module can output the glitch state of the beam current in the form of an optical signal, and the trigger condition depends on the judgment results of the current amplitude exceeding the limit determination circuit module and the current amplitude exceeding time duration determination module.

In a specific application example, there are more than two beam current monitoring and response systems, and all beam current monitoring and response systems are connected in series through optical fibers to realize simultaneous monitoring. Further, one of the more than two beam monitoring and response systems is preset as the head system, and other beam monitoring and response systems except the head system send Glitch optical fiber signals, and the upper-level system will receive this signal And continue to transmit the Glitch fiber optic signal to the upper level until it is transmitted to the head system.

In a specific application example, the function self-inspection module can detect whether the self-monitoring function is normal.

As shown in FIG. 3 , the present invention can monitor the variation degree of the Glitch amplitude of the system through the hardware circuit shown in the figure. In the present invention, a voltage comparator is used to compare the real-time monitoring value with the set threshold, and the high/low level signal RAW_GLITCH can be output to the FPGA, and the high/low level signal RAW_GLITCH can drive the clock of the FPGA through software programming FPGA, and monitor the duration of Glitch occurrence , if the duration exceeds the limit, the FPGA can output a high/low level signal PROCESSED_GLITCH to drive the optical fiber, and transmit the Glitch occurrence signal to the dose control system, and the determination of the Glitch can be performed by the hardware circuit. The present invention judges whether the current amplitude and duration exceed the limit respectively through the hardware circuit shown in FIG. 3 and the hardware programmable device. If it exceeds the limit, it is regarded as Glitch.

When working, before the machine is ready for ion implantation, the self-checking module can check whether the self-monitoring function is normal according to the function. The upper computer sends the Glitch analog signal to the system of the present invention, if the system can monitor the analog Glitch signal and respond to it, it means that the system functions normally. The feedback value of the current feedback channel is received by the current feedback module, and the collected real-time signal is divided into two channels, one of which is transmitted to the host computer as the feedback value display of the power supply current, and the other is transmitted to the current amplitude exceeding limit determination circuit , use the hardware circuit to determine whether the real-time acquisition signal exceeds the threshold set by the user. If the current amplitude exceeds the limit, the current amplitude excess determination module sends the Glitch optical fiber signal to the current amplitude excess time length determination module. Once the module receives signal, the hardware programmability of the FPGA can be used to determine whether the current amplitude exceeds the threshold set by the user, and if the duration is also exceeded, the Glitch state output module can output the Glitch state of the beam current to the dose in the form of an optical signal Control system, the dose control system performs dose compensation by controlling power on and off, motor movement and product.

As an optimized embodiment, in this example, as shown in Figure 2, in addition to being able to directly communicate with the dose control system through an optical fiber, the system of the present invention can be used alone, and can also connect multiple monitoring systems in series through an optical fiber , Connect the Glitch signals output by each system in series through optical fiber, realize simultaneous monitoring of multiple power supplies, and uniformly output Glitch optical fiber signals to achieve the effect of simultaneous monitoring of multiple systems. In the whole series system, if other controller systems except the head system send Glitch fiber optic signal, the upper level system will receive the signal and continue to transmit the Glitch fiber optic signal to the upper level until it is transmitted to the head system, and then communicate with the dose The control systems work together.

The above are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims (10)

1. A beam monitoring and response system for an ion implanter, comprising:

the power supply enabling module is used for controlling whether the power supply is activated or not;

the voltage setting and feedback module is used for setting a power supply voltage value and receiving a feedback value of the power supply voltage;

the current feedback module is used for receiving a power supply current feedback value;

the current amplitude overrun judging module is used for comparing the power supply current feedback value with a preset current threshold value and sending out a signal according to a comparison result;

the current amplitude overrun duration judging module is used for comparing the current amplitude overrun duration with a preset duration threshold value and sending out a signal according to a comparison result;

and the switch state output module is used for judging whether the beam current outputs a switch signal according to the current amplitude overrun judging module and the current amplitude overrun duration result.

2. The beam current monitoring and response system for an ion implanter according to claim 1, wherein the power supply enabling module activates the power supply by controlling the relay on and off through a hardware circuit.

3. The beam current monitoring and response system according to claim 1, wherein the voltage setting and feedback module is configured to set a power supply voltage on a host computer software according to a user's requirement, and the host computer receives the feedback value of the power supply voltage and displays the feedback value on a page.

4. The beam current monitoring and response system for an ion implanter according to claim 1, wherein the current feedback module is configured to receive a feedback value of the current feedback channel, divide the acquired real-time signal into two paths, transmit one path to the upper computer terminal as a feedback value of the power supply current for display, and transmit the other path to the current amplitude overrun decision circuit for comparison with a preset current threshold.

5. The beam monitoring and response system according to claim 1, wherein the current amplitude overrun determination module is configured to determine whether the real-time acquisition signal exceeds a threshold set by a user using a hardware circuit.

6. The beam current monitoring and response system for an ion implanter according to claim 1, wherein the current amplitude overrun period determining module is configured to receive the level signal transmitted by the current amplitude overrun determining module, and determine whether the current amplitude overrun period exceeds a preset threshold by using the hardware programmability of the FPGA.

7. The beam monitoring and response system for an ion implanter according to claim 1, wherein the switch state output module is configured to output the switch state of the beam in the form of an optical signal, and the trigger condition depends on the determination results of the current amplitude overrun determination circuit module and the current amplitude overrun duration determination module.

8. The beam monitoring and response system for an ion implanter according to any of claims 1 to 7, wherein the number of beam monitoring and response systems is two or more, and all beam monitoring and response systems are connected in series by optical fibers to realize simultaneous monitoring.

9. The beam monitoring and response system according to claim 1, wherein one of the beam monitoring and response systems is a head system, and the other beam monitoring and response systems except the head system send out a Glitch fiber signal, and the previous system will receive the signal and continue to transmit the Glitch fiber signal to the previous stage until the signal is transmitted to the head system.

10. The beam current monitoring and response system for an ion implanter according to any of claims 1-7, further comprising a functional self-test module for detecting whether self-monitoring function is normal.

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