Ion implantation method of an ion implanter

Abstract

The present invention discloses an ion implantation method for an ion implanter, comprising the steps of: 1) before ion implantation, using an initial scanning electric field to control the beam current to scan in two directions, namely horizontal and vertical, and detecting the beam current data in the two directions; 2) obtaining the relationship between the beam spot position and the scanning electric field value in the corresponding direction and the beam spot width according to the beam current data in the two directions, and further obtaining the scanning electric field magnitude range in each direction; 3) using the scanning electric field obtained in step 2) to control the beam current to scan in the two directions, and detecting the beam current data in the two directions; 4) judging whether the scanning electric field covers the entire workpiece in each direction according to the beam current data obtained in step 3); if so, ion implantation is carried out. The present invention realizes the accurate confirmation of the magnitude of the scanning electric field before ion implantation, and at the same time realizes the detection of the scanning range and uniformity, ensures the accuracy and reliability of subsequent ion implantation, and has a high degree of automation.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of semiconductor equipment, and particularly relates to an ion implantation method for an ion implanter. Background Art

[0002] An ion implanter is one of the key equipment in semiconductor processes. The main purpose of beam current and dose measurement and control in an ion implanter is to accurately collect and control the ion beam current and dose, and to control the ion beam scanning movement and the target stage movement in real time to uniformly and accurately implant ions into the wafer surface according to the set dose, which belongs to one of the key technologies of an ion implanter. The full-electric-scan ion implanter is a type of ion implanter. Due to its fast scanning speed, it can meet the implantation process requirements of some special materials sensitive to temperature. At the same time, the equipment structure is relatively simple and the production cost is relatively low, so there is a certain market demand.

[0003] Currently, when an ion implanter performs ion implantation, it is necessary to first determine the magnitude of the scanning voltage to improve the equipment performance. The traditional method uses the theoretical relationship calculated in the ion implanter structure design to deduce the relationship between the beam spot position and the scanning electric field value, and then determines the magnitude of the scanning voltage. However, there are often deviations between the above theoretical calculations and the actual situation. In order to avoid inaccurate magnitudes of the implanted scanning voltage caused by the deviations of the above theoretical calculations, problems such as insufficient overscanning occur, it is necessary to collect the beam current scanning signal waveform with an oscilloscope, and then manually analyze and confirm the overscanning situation and whether it is necessary to adjust the range of the scanning voltage. Due to relying on manual confirmation, there is a hidden danger of manual judgment errors and it limits the automatic operation ability of the equipment. Summary of the Invention

[0004] 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 an ion implantation method for an ion implanter with high ion implantation accuracy and high automation level.

[0005] To solve the above technical problem, the technical solution proposed by the present invention is:

[0006] An ion implantation method for an ion implanter, comprising the steps of:

[0007] 1) Before ion implantation, use the initial scanning electric field to control the beam current to scan in the horizontal and vertical directions, and detect the beam current data in the horizontal and vertical directions;

[0008] 2) Obtain the relationship between the beam spot position and the scanning electric field value and the beam spot width in the corresponding direction according to the beam current data in the horizontal and vertical directions, and obtain the range of the scanning electric field magnitude in each direction according to the relationship between the beam spot position and the scanning electric field value and the beam spot width;

[0009] 3) Use the scanning electric field obtained in step 2) to control the beam current to scan in the horizontal and vertical directions, and detect the beam current data in the horizontal and vertical directions;

[0010] 4) Judge whether the scanning electric field covers the entire workpiece in each direction according to the beam current data obtained in step 3); if the scanning electric field covers the entire workpiece in each direction, then perform ion implantation.

[0011] Preferably, in step 4), before ion implantation, it also includes detecting the uniformity of the beam current distribution. The specific process is as follows:

[0012] Output the scanning waveforms in the horizontal and vertical directions, with high-frequency scanning in one direction and low-frequency scanning in the other direction;

[0013] Obtain the beam current data around the workpiece, compare the beam current data with the preset standard beam current data, and judge whether the beam current distribution is uniform according to the comparison result.

[0014] Preferably, when it is judged that the beam current distribution is non-uniform, the scanning waveforms in the horizontal and vertical directions are corrected. Specifically: correct the slope of the scanning waveform according to the deviation between the beam currents at different positions.

[0015] Preferably, the specific process of step 1) is as follows:

[0016] 1.1) Obtain the theoretical original scanning waveforms in the horizontal and vertical directions, output the original scanning waveform in the horizontal direction, and form a high-speed scanning electric field; under the action of the high-speed scanning electric field, the beam current forms a horizontal broadband beam from a dot-shaped beam spot;

[0017] 1.2) Perform a single low-speed scan in the vertical direction, and synchronously collect the beam current in real time according to the vertical scanning electric field intensity during the scanning process to obtain the beam current data in the vertical direction;

[0018] 1.3) Output the original scanning waveform in the vertical direction, and form a high-speed scanning electric field; under the action of the high-speed scanning electric field, the beam current forms a vertical broadband beam from a dot-shaped beam spot;

[0019] 1.4) Perform a single low-speed scan in the horizontal direction, and synchronously collect the beam current in real time according to the horizontal scanning electric field intensity during the scanning process to obtain the beam current data in the horizontal direction.

[0020] Preferably, the specific process of step 2) is as follows:

[0021] 2.1) According to the beam current data in each direction, obtain the beam profile in each direction;

[0022] 2.2) According to the beam profile, obtain the relationship between the beam spot position and the scanning electric field value in the corresponding direction, and the beam spot width W B, the scanning voltage difference V corresponding to the peak-to-peak value of the beam profile D and the midpoint voltage V of the beam profile peak Z ;

[0023] 2.3) Obtain the range of the scanning electric field magnitude in each direction according to the relationship between the beam spot position and the scanning electric field value, the beam spot width W B , the scanning voltage difference V corresponding to the peak-to-peak value of the beam profile D and the midpoint voltage V of the beam profile peak Z .

[0024] Preferably, in step 2.3), the range of the scanning electric field magnitude is V Z - V D / L * (L / 2 + W B ) to V Z + V D / L * (L / 2 + W B ).

[0025] Preferably, the specific process of step 3) is as follows:

[0026] 3.1) Output the horizontal direction scanning waveform and form a high-speed scanning electric field. Under the action of the high-speed scanning electric field, the beam current forms a horizontal direction wideband beam from the dot-shaped beam spot;

[0027] 3.2) Perform a single low-speed scan in the vertical direction, and synchronously collect the beam current data in the vertical direction in real time according to the vertical direction scanning electric field intensity during the scanning process;

[0028] 3.3) Output the vertical direction scanning waveform and form a high-speed scanning electric field. Under the action of the high-speed scanning electric field, the beam current forms a vertical direction wideband beam from the dot-shaped beam spot;

[0029] 3.4) Perform a single low-speed scan in the horizontal direction, and synchronously collect the beam current data in the horizontal direction in real time according to the horizontal direction scanning electric field intensity during the scanning process.

[0030] Preferably, the specific process of step 4) is as follows:

[0031] 4.1) Obtain the beam profile in the corresponding direction according to the beam current data in each direction; where the abscissa in the beam profile is the scanning voltage and the ordinate is the collected beam current magnitude;

[0032] 4.2) Judge whether the scanning range covers the entire workpiece according to the beam profile.

[0033] Preferably, in step 4.2), if the beam current at the scanning start point and the end point in the beam profile is close to 0, and both beam peaks are within the scanning range, it means that the scanning range covers the entire workpiece.

[0034] Preferably, beam current data is detected by a plurality of Faraday cups around the workpiece; wherein the plurality of Faraday cups are arranged in a rectangle.

[0035] Compared with the prior art, the advantages of the present invention are as follows:

[0036] Before ion implantation, the present invention uses a scanning electric field to control the beam current to scan in two directions, vertical and horizontal. The relationship between the beam spot position and the scanning electric field value and the beam spot width are obtained from the beam current data detected by a plurality of Faraday cups around the workpiece. Then, according to the relationship between the beam spot position and the scanning electric field value and the beam spot width, the numerical range of the scanning electric field required for implantation in this direction is determined. Compared with the theoretical calculation method, its accuracy is higher, thus avoiding the problem of insufficient overscanning. At the same time, compared with the method of manual analysis and adjustment with the help of an oscilloscope, its adjustment accuracy is higher and the automation level is also higher; on the basis of confirming the scanning voltage magnitude range, the beam current data is used to confirm whether the beam current scanning range covers the entire workpiece under the scanning electric field within this magnitude range, and whether the beam current distribution uniformity meets the requirements is detected, realizing the detection of the scanning range and the uniformity detection, ensuring the accuracy and reliability of subsequent ion implantation. The above method gets rid of the dependence on oscilloscopes and manual confirmation of foreign similar models, effectively improving the upper limit of the automation ability of the full-electric-scan ion implanter and the ion implantation uniformity. Description of the Drawings

[0037] Figure 1 It is a flowchart of the ion implantation method of the present invention in an embodiment.

[0038] Figure 2 Schematic diagram of the hardware design of the full-electric-scan dose controller;

[0039] Figure 3 It is a schematic diagram of the X / Y direction beam profile coordinates in the present invention.

[0040] Figure 4 It is a schematic diagram of the influence of the arrangement of four Faraday cups on the beam profile diagram in the present invention.

[0041] Figure 5 It is a schematic diagram of the scanning waveform correction principle in the present invention. Detailed Embodiments

[0042] The present invention will be further described below in conjunction with the specification drawings and specific embodiments.

[0043] As Figure 1 shown, the ion implantation method of the ion implanter in the embodiment of the present invention includes a pre-treatment process before ion implantation, specifically including:

[0044] 1) Before ion implantation, an initial scanning electric field is used to control the beam current to scan in both the horizontal and vertical directions, and the beam current data in both the horizontal and vertical directions are detected;

[0045] 2) Based on the beam current data in both the horizontal and vertical directions, the relationships between the beam spot positions and the scanning electric field values in the corresponding directions and the beam spot widths are obtained, and based on the relationships between the beam spot positions and the scanning electric field values and the beam spot widths, the ranges of the scanning electric field magnitudes in each direction are obtained;

[0046] 3) The scanning electric field obtained in step 2) is used to control the beam current to scan in both the horizontal and vertical directions, and the beam current data in both the horizontal and vertical directions are detected;

[0047] 4) Based on the beam current data obtained in step 3), it is judged whether the scanning electric field covers the entire workpiece in each direction; if the scanning electric field covers the entire workpiece in each direction, ion implantation is carried out.

[0048] Further, in step 4), before ion implantation, it also includes the detection of the beam current distribution uniformity, and the specific process is as follows:

[0049] Output the scanning waveforms in both the horizontal and vertical directions, with one direction having high-frequency scanning and the other having low-frequency scanning;

[0050] Obtain the beam current data around the workpiece, compare the beam current data with the preset standard beam current data, and judge whether the beam current distribution is uniform according to the comparison result; when it is judged that the beam current distribution is non-uniform, the scanning waveforms in both the horizontal and vertical directions are corrected, specifically: the slope of the scanning waveform is corrected according to the deviation between the beam currents at different positions.

[0051] Specifically, when judging whether the requirement for the beam current distribution uniformity is met, in the two scanning directions of vertical and horizontal, one scanning direction uses high-frequency electric field scanning and the other scanning direction uses low-speed single-time electric field scanning, and the two scanning periods differ by more than 10 times. Then, the beam current distribution uniformity is calculated from the beam current data detected by multiple Faraday cups around the workpiece. If it is non-uniform, the scanning electric field waveforms in the vertical or horizontal direction are corrected according to the beam current data received by the Faraday cups around the workpiece, so as to improve the beam current distribution uniformity after electric field scanning.

[0052] Before ion implantation, the present invention controls the beam current to scan in the vertical and horizontal directions by using a scanning electric field, obtains the relationship between the beam spot position and the scanning electric field value and the beam spot width from the beam current data detected by multiple Faraday cups around the workpiece, and then determines the numerical range of the scanning electric field required for implantation in this direction according to the relationship between the beam spot position and the scanning electric field value and the beam spot width. Compared with the theoretical calculation method, its accuracy is higher, thus avoiding the problem of insufficient overscanning. At the same time, compared with the method of manual analysis and adjustment with the help of an oscilloscope, its adjustment accuracy is higher and the automation level is also higher. On the basis of confirming the range of the scanning voltage magnitude, the beam current data is further used to confirm whether the beam current scanning range covers the entire workpiece under the scanning electric field within this magnitude range, and to detect whether the beam current distribution uniformity meets the requirements, realizing the detection of the scanning range and the uniformity, and ensuring the accuracy and reliability of subsequent ion implantation. The above method gets rid of the dependence on oscilloscopes and manual confirmation of foreign similar models, effectively improving the upper limit of the automation ability of the fully electric-scanning ion implanter and the ion implantation uniformity.

[0053] In a specific embodiment, the specific process of step 1) is as follows:

[0054] 1.1) Obtain the theoretical original scanning waveforms in the horizontal and vertical directions, output the original scanning waveform in the horizontal direction, and form a high-speed scanning electric field; under the action of the high-speed scanning electric field, the beam current forms a horizontal broadband beam from a dot-shaped beam spot.

[0055] 1.2) Perform a single low-speed scan in the vertical direction, and synchronously collect the beam current in real time according to the vertical scanning electric field intensity during the scanning process to obtain the beam current data in the vertical direction.

[0056] 1.3) Output the original scanning waveform in the vertical direction, and form a high-speed scanning electric field; under the action of the high-speed scanning electric field, the beam current forms a vertical broadband beam from a dot-shaped beam spot.

[0057] 1.4) Perform a single low-speed scan in the horizontal direction, and synchronously collect the beam current in real time according to the horizontal scanning electric field intensity during the scanning process to obtain the beam current data in the horizontal direction.

[0058] In a specific embodiment, the specific process of step 2) is as follows:

[0059] 2.1) Obtain the beam profiles in each direction according to the beam current data in each direction.

[0060] 2.2) Obtain the relationship between the beam spot position and the scanning electric field value, the beam spot width WB, the scanning voltage difference VD corresponding to the peak-to-peak value of the beam profile, and the midpoint voltage VZ of the beam profile peak in the corresponding direction according to the beam profiles.

[0061] 2.3) Obtain the scanning electric field magnitude range in each direction based on the relationship between the beam spot position and the scanning electric field value, the beam spot width WB, the scanning voltage difference VD corresponding to the peak-to-peak value of the beam profile, and the midpoint voltage VZ of the beam profile peak. Specifically, in step 2.3), the scanning electric field magnitude range is from VZ - VD / L * (L / 2 + WB) to VZ + VD / L * (L / 2 + WB).

[0062] In a specific embodiment, the specific process of step 3) is as follows:

[0063] 3.1) Output the horizontal direction scanning waveform and form a high-speed scanning electric field. Under the action of the high-speed scanning electric field, the beam current forms a horizontal direction broadband beam from a dot-like beam spot.

[0064] 3.2) Perform a single low-speed scan in the vertical direction, and synchronously collect the beam current data in the vertical direction in real time according to the vertical direction scanning electric field intensity during the scanning process.

[0065] 3.3) Output the vertical direction scanning waveform and form a high-speed scanning electric field. Under the action of the high-speed scanning electric field, the beam current forms a vertical direction broadband beam from a dot-like beam spot.

[0066] 3.4) Perform a single low-speed scan in the horizontal direction, and synchronously collect the beam current data in the horizontal direction in real time according to the horizontal direction scanning electric field intensity during the scanning process.

[0067] In a specific embodiment, the specific process of step 4) is as follows:

[0068] 4.1) Obtain the beam profile in the corresponding direction based on the beam current data in each direction; where the abscissa in the beam profile is the scanning voltage and the ordinate is the collected beam current magnitude.

[0069] 4.2) Determine whether the scanning range covers the entire workpiece according to the beam profile. If the beam current at the scanning start point and the end point in the beam profile is close to 0, and both beam peaks are within the scanning range, it indicates that the scanning range covers the entire workpiece.

[0070] In the above steps 1) and 3), one direction uses high-speed cyclic scanning, and the other direction uses single low-speed scanning. At the same time, the beam current magnitude is synchronously collected according to the magnitude of the scanning voltage to obtain the beam profile, as Figure 3 shown. The high-speed scanning electric field is a high-frequency electric field cyclic scanning, the scanning frequency is greater than 50 Hz, and the single scan time of the single low-speed electric field scan is greater than 0.2 seconds.

[0071] In a specific embodiment, beam current data is detected by four Faraday cups around the workpiece; the four Faraday cups are arranged in a rectangle, enabling the beam profile to simultaneously collect the beam currents received by the four Faraday cups, so as to accurately measure the beam spot width (if the four Faraday cups are not arranged in a matrix, the obtained beam profile diagram will be the superposition of the beam profiles of adjacent Faraday cups, and there will be a large deviation in the beam spot width (the full width at half maximum of the beam profile) calculated from such a beam profile).

[0072] Among them, the detected beam current data is converted from current to voltage through a conversion circuit, and then the voltage signal is amplified and filtered. Here, the single-stage maximum time constant RC of the filter circuit (multi-stage operational amplifier circuit) is less than the time of a single low-speed electric field scan in the two electric field scanning directions and greater than the period of the high-speed electric field scan.

[0073] During ion implantation, the beam current is scanned simultaneously in the vertical and horizontal directions, and the beam current scanning range can completely cover the workpiece to be implanted, thereby realizing the ion implantation function. Among them, the implanted dose is calculated by collecting the beam current data detected by multiple Faraday cups around the workpiece during ion implantation, which can accurately collect and control the ion beam current and dose of the full-electric-scan ion implanter, so that ions are uniformly and accurately implanted into the wafer according to the set dose, and it is judged whether the beam current size exceeds the set range; if the beam current size exceeds the set range, the beam current is deflected outside the workpiece range, thereby stopping the implantation. In addition, uniformity detection is also carried out during ion implantation. Among them, the dose is integrated and statistically analyzed by three Faraday cups, and one Faraday cup (Faraday cups 1#, 2#, 3#, and 4# rotate in turn, such as switching once every 1 s, and a polling can be completed in 4 s) is used to monitor the uniformity.

[0074] To better understand the above technical solutions, the above technical solutions will be described in detail below in combination with each specification drawing and specific implementation manners:

[0075] 1. Calculate the theoretical original scan waveforms in the X and Y directions (X represents the horizontal direction, Y represents the vertical direction, the same below) according to the current beam energy and equipment performance parameters, and output the original scan waveform in the X direction. The original scan waveform in the X direction for high-speed scanning controls the electric scanning device to form a high-speed scanning electric field. Under the action of the high-speed scanning electric field, the beam current forms a broadband beam in the X direction from a dot-shaped beam spot, as Figure 2 shown;

[0076] 2. Single low-speed scan in the Y direction. During the scan, the beam current of the Faraday cup is synchronously collected in real time according to the Y-direction scan electric field intensity, and the beam profile diagram in the Y direction as Figure 2 shown is obtained;

[0077] 3. Determine whether the beam profile in the Y direction is normal (judge according to parameters such as the shape of the beam width, whether it is close to a Gaussian distribution, whether the beam width is too large or too small, and the number of beam peaks, etc. Specifically, select one or more parameters according to the actual situation for judgment). If it is normal, calculate the relationship between the beam spot position in the Y direction and the scanning electric field value based on the beam profile diagram in the Y direction (where the scanning voltage and the beam spot moving distance are linearly related, such as Figure 3 the coefficient a in the curve Y = aX in Figure 3 the scanning voltage difference V corresponding to the peak-to-peak value of the beam profile in D the corresponding beam spot moving distance is the structural distance L of the Faraday cup, and the midpoint voltage of the beam profile peak is V Z ), the beam spot width W in the Y direction B , and proceed to the next step. If it is not normal, the process ends;

[0078] 4. Output the original scanning waveform in the Y direction. The original scanning waveform in the Y direction of the high-speed scanning controls the electro-scanning device to form a high-speed scanning electric field. Under the action of the high-speed scanning electric field, the beam current forms a broadband beam in the Y direction from a dot-like beam spot, as Figure 2 shown;

[0079] 5. Perform a single low-speed scan in the X direction. During the scan, synchronously collect the beam current of the Faraday cup in real time according to the scanning electric field intensity in the X direction, and obtain the beam profile diagram in the X direction as Figure 2 shown;

[0080] 6. Determine whether the beam profile in the X direction is normal. If it is normal, calculate the relationship between the beam spot position in the X direction and the scanning electric field value based on the beam profile diagram in the X direction (the scanning voltage and the beam spot moving distance are linearly related, Figure 3 the scanning voltage difference V corresponding to the peak-to-peak value of the beam profile in D the corresponding beam spot moving distance is the structural distance L of the hardware Faraday cup, and the midpoint voltage of the beam profile peak is V Z ), the beam spot width in the X direction, and proceed to the next step. If it is not normal, the process ends;

[0081] 7. Calculate the scanning voltage ranges in the X and Y directions required to cover the entire workpiece and multiple Faraday cups around it, and generate the scanning waveforms in the X and Y directions. Set the number of uniformity correction times to zero; specifically, the specific calculation process for calculating the scanning voltage range is: The scanning voltage range calculated according to the parameters in steps 3 and 6 is:

[0082] V Z -V D / L * (L / 2 + W B ) to V Z +V D / L * (L / 2 + W B );

[0083] where L is Figure 2 the structural distance of the Faraday cup shown in

[0084] 8. Output the X-direction scanning waveform. The original scanning waveform in the X direction of high-speed scanning controls the electro-scanning device to form a high-speed scanning electric field. Under the action of the high-speed scanning electric field, the beam current forms a broadband beam in the X direction from a dot-like beam spot, as Figure 2 shown;

[0085] 9. Single low-speed scanning in the Y direction. During the scanning process, synchronously collect the beam current of the Faraday cup in real time according to the electric field strength of the Y-direction scanning, and obtain a beam profile diagram as Figure 3 shown. The abscissa is the scanning voltage, and the ordinate is the magnitude of the collected beam current;

[0086] 10. Judge whether the scanning range in the Y direction covers the entire workpiece and multiple Faraday cups around it according to the beam profile diagram in the Y direction, as Figure 3 shown. If the beam currents at the starting point and the ending point of the scanning are close to 0, and both beam peaks are within the scanning range, it means that the scanning range covers the entire workpiece. If it is completely covered, proceed to the next step; otherwise, end the process;

[0087] 11. Output the Y-direction scanning waveform. The original scanning waveform in the Y direction of high-speed scanning controls the electro-scanning device to form a high-speed scanning electric field. Under the action of the high-speed scanning electric field, the beam current forms a broadband beam in the Y direction from a dot-like beam spot, as Figure 2 shown;

[0088] 12. Single low-speed scanning in the X direction. During the scanning process, synchronously collect the beam current of the Faraday cup in real time according to the electric field strength of the X-direction scanning, and obtain a beam profile diagram as Figure 3 shown. The abscissa is the scanning voltage, and the ordinate is the magnitude of the collected beam current;

[0089] 13. Judge whether the scanning range in the X direction covers the entire workpiece and multiple Faraday cups around it according to the beam profile diagram in the X direction, as Figure 3 shown. If the beam currents at the starting point and the ending point of the scanning are close to 0, and both beam peaks are within the scanning range, it means that the scanning range covers the entire workpiece. If it is completely covered, proceed to the next step; otherwise, end the process;

[0090] 14. Output the scanning waveforms in the X and Y directions, with one direction for high-frequency scanning and the other for low-frequency scanning;

[0091] 15. Obtain the beam current data of four Faraday cups around the workpiece, calculate the beam current distribution uniformity, and determine whether the "uniformity meets the requirement or the number of uniformity correction times exceeds the standard" (the beam current data is the integral value within a certain time (such as 1 second) of the beam current. For the four integral values of the four Faraday cups, take the standard deviation / mean value. If the value is greater than the uniformity index, the uniformity is not met). If so, the process ends; if not, proceed to the next step;

[0092] 16. Correct the scanning waveforms in the X and Y directions according to the uniformity distribution, increment the uniformity correction times by 1, and go to step 14. Specifically, the scanning voltage of the original waveform changes linearly with time, and the change rate is a constant. When correcting the waveform, according to the actual uniformity detection, the slope of the scanning waveforms in the X and Y directions is corrected respectively based on the beam current difference between the left and right Faraday cups and the beam current difference between the upper and lower Faraday cups. The slope at the position with a larger beam current is increased, and the slope at the position with a smaller beam current is decreased. The proportion of increase and decrease is calculated from the beam current difference ratio, and then the slope is linearly extended.

[0093] As Figure 5 shown, the average beam current of the left Faraday cup I L is (80 + 80) / 2 = 80 uA, the average beam current of the right Faraday cup I R is (120 + 120) / 2 = 120 uA, and the average value of the four Faraday cups I0 is (I L + I R) / 2 = 100 uA; assuming the original slope K0 is 1, the slope correction at the K1 position of the left Faraday cup is K0 * I L / I0 = 0.8, and the slope correction at the K2 position of the right Faraday cup is K0 * I R / I0 = 1.2. The slopes at other position points are linearly extended based on the values of these two points; the same applies to the Y direction.

[0094] As shown in this disclosure and the claims, unless the context clearly indicates an exceptional situation, words such as "a", "an", "one", and / or "the" are not specifically singular and may also include the plural. The terms "first", "second", and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are only used to distinguish different components. Similarly, words such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. "Connection" or "connected" and similar terms are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0095] The above are only the preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, several improvements and refinements made without departing from the principle of the present invention should be regarded as within the protection scope of the present invention.

Claims

1. An ion implantation method for an ion implanter, characterized in that, Including the steps: 1) Before ion implantation, use the initial scanning electric field to control the beam current to scan in the horizontal and vertical directions, and detect the beam current data in the horizontal and vertical directions; 2) Obtain the relationship between the beam spot position and the scanning electric field value and the beam spot width in the corresponding directions according to the beam current data in the horizontal and vertical directions, and obtain the scanning electric field magnitude range in each direction according to the relationship between the beam spot position and the scanning electric field value and the beam spot width; 3) Use the scanning electric field obtained in step 2) to control the beam current to scan in the horizontal and vertical directions, and detect the beam current data in the horizontal and vertical directions; 4) Judge whether the scanning electric field covers the entire workpiece in each direction according to the beam current data obtained in step 3); if the scanning electric field covers the entire workpiece in each direction, perform ion implantation; The specific process of step 1) is: Obtain the theoretical original scanning waveform in the horizontal direction, output the original scanning waveform in the horizontal direction, and form a high-speed scanning electric field; perform a single low-speed scan in the vertical direction, and synchronously collect the beam current according to the vertical scanning electric field intensity in real time during the scanning process to obtain the beam current data in the vertical direction; Obtain the theoretical original scanning waveform in the vertical direction, output the original scanning waveform in the vertical direction, and form a high-speed scanning electric field; perform a single low-speed scan in the horizontal direction, and synchronously collect the beam current according to the horizontal scanning electric field intensity in real time during the scanning process to obtain the beam current data in the horizontal direction; The specific process of step 2) is: 2.1) Obtain the beam profile in each direction according to the beam current data in each direction; 2.2) Obtain the relationship between the beam spot position and the scanning electric field value in the corresponding direction, the beam spot width W B , the scanning voltage difference V corresponding to the peak-to-peak value of the beam profile D and the midpoint voltage V of the beam profile peak Z ; 2.3) According to the relationship between the beam spot position and the scanning electric field value, the beam spot width W B , the scanning voltage difference V corresponding to the peak-to-peak value of the beam profile D and the midpoint voltage V of the beam profile peak Z obtain the range of the scanning electric field magnitude in each direction.

2. The ion implantation method of the ion implanter according to claim 1, characterized in that, In step 4), before ion implantation, it also includes the detection of the beam current distribution uniformity, and the specific process is: Output the scanning waveforms in the horizontal and vertical directions, with one direction performing high-frequency scanning and the other performing low-frequency scanning; Obtain the beam current data around the workpiece, compare the beam current data with the preset standard beam current data, and judge whether the beam current distribution is uniform according to the comparison result.

3. The ion implantation method of the ion implanter according to claim 2, characterized in that, When it is judged that the beam current distribution is non-uniform, correct the scanning waveforms in the horizontal and vertical directions, specifically: correct the slope of the scanning waveform according to the deviation between the beam currents at different positions.

4. The ion implantation method of the ion implanter according to claim 1, wherein The scanning electric field magnitude range in step 2.3) is V Z -V D / L * (L / 2 + W B ) to V Z +V D / L * (L / 2 + W B ).

5. The ion implantation method of the ion implanter according to claim 1 or 2 or 3, characterized in that, The specific process of step 3) is: 3.1) Output the horizontal direction scanning waveform and form a high-speed scanning electric field. Under the action of the high-speed scanning electric field, the beam current forms a horizontal direction broadband beam from a dot-shaped beam spot; 3.2) Perform a single low-speed scan in the vertical direction, and synchronously collect the beam current data in the vertical direction according to the vertical scanning electric field intensity in real time during the scanning process; 3.3) Output the vertical direction scanning waveform and form a high-speed scanning electric field. Under the action of the high-speed scanning electric field, the beam current forms a vertical direction broadband beam from a dot-shaped beam spot; 3.4) Perform a single low-speed scan in the horizontal direction, and synchronously collect the beam current data in the horizontal direction according to the horizontal scanning electric field intensity in real time during the scanning process.

6. The ion implantation method of the ion implanter according to claim 5, characterized in that, The specific process of step 4) is: 4.1) Obtain the beam profile in the corresponding direction according to the beam current data in each direction; where the abscissa in the beam profile is the scanning voltage and the ordinate is the collected beam current magnitude; 4.2) Judge whether the scanning range covers the entire workpiece according to the beam profile.

7. The ion implantation method of the ion implanter according to claim 6, characterized in that, In step 4.2), if the beam currents at the scanning start point and the scanning end point in the beam profile are close to 0, and both beam peaks are within the scanning range, it indicates that the scanning range covers the entire workpiece.

8. The ion implantation method of the ion implanter according to claim 1 or 2 or 3, characterized in that, The beam current data is detected by multiple Faraday cups around the workpiece; the multiple Faraday cups are arranged in a rectangular pattern.

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