Laser process for automatically removing film layer of graphite cylinder part

Abstract

The invention discloses a laser process for automatically removing a film layer of a graphite cylinder part, and belongs to the technical field of semiconductor part cleaning, and the laser process comprises the following steps: S1, checking the appearance of a workpiece by using a flashlight, recording abnormal workpieces such as bumping and scratching, and measuring and recording the resistance, EDS, diameter and weight of the workpiece; and S2, performing laser cleaning on the workpiece by using a laser process. And S3, surface blowing is conducted on the workpiece through CDA till no macroscopic particulate matter residues exist on the surface of the workpiece. And S4, the surface of the workpiece is wiped with nano dust-free cloth dipping I PA, and after wiping is completed, the I PA on the surface of the workpiece is wiped dry with new nano dust-free cloth. And S5, baking the workpiece at a high temperature, naturally cooling the baked workpiece, and taking out the workpiece to obtain a cleaned workpiece. According to the laser process, when the film layer of the graphite cylinder part is removed, the substrate size and morphology of the workpiece can be kept, and the diameter loss and the weight loss can be reduced by optimizing mechanical motion parameters.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor component cleaning, and in particular relates to a laser process for automatically removing a film layer of a graphite cylindrical component. Background Art

[0002] Ion implantation is a process that accelerates a beam of ions such as boron, phosphorus, and arsenic to a certain energy and then injects it into the surface layer of a wafer material to change the surface material properties. The materials that make up the components of the ion implantation device are required to be high-purity materials with excellent heat resistance, thermal conductivity, less corrosion caused by the ion beam, and low impurity content. High-purity graphite meets these requirements and can be used in flight tubes, various slits, electrodes, electrode covers, catheters, beam terminators, etc. of ion implantation equipment. The traditional cleaning process for graphite parts currently uses sandblasting.

[0003] However, the sandblasting process has significant drawbacks:

[0004] Substrate damage: The physical impact of sandblasting causes the graphite surface roughness to increase (>1.5μm), diameter loss (>0.02mm) and weight loss (>2g), affecting dimensional accuracy;

[0005] Residual risk: It is difficult to completely remove impurities in micron-sized pores, and EDS testing often detects metal residues such as K and Ca;

[0006] Deterioration of electrical performance: Surface roughening increases contact resistance (>1Ω) and reduces conductive uniformity;

[0007] The process is uncontrollable: parameters rely on manual experience, and there is a lack of coordinated optimization methods for systematic energy and mechanical motion.

[0008] Currently, laser cleaning equipment is widely popular as the latest graphite cleaning equipment. However, if there is a deviation in parameter adjustment, it will easily lead to poor cleaning effect. In order to meet the cleaning requirements, the present invention improves the equipment according to the product to be cleaned, and optimizes and debugs the improved cleaning process to achieve the final cleaning requirements.

[0009] It should be noted that the above content falls within the technical knowledge of the inventor and does not necessarily constitute prior art. Summary of the Invention

[0010] In order to solve the above problems, the purpose of the present invention is to provide a laser process for automatically removing the film layer of graphite cylindrical parts. When removing the film layer of graphite cylindrical parts, the base size and morphology of the workpiece can be maintained, and the diameter loss and weight loss can be reduced by optimizing the mechanical motion parameters, which is better than the traditional sandblasting process. Tests have shown that impurities can be completely removed at a height of 8-10 cm and a laser energy of 60-80 kHz. EDS verification shows that only C / O elements remain, eliminating metal contamination such as Na / Al / Si, and can accurately remove the film layer with zero metal residue.

[0011] To achieve the above objectives, the present invention proposes a laser process for automatically removing the film layer of a graphite cylindrical component, the laser process comprising the following steps:

[0012] S1: Incoming material inspection;

[0013] Use a flashlight to inspect the appearance of the workpiece, record any abnormalities such as bumps and scratches, and measure and record the resistance, EDS, diameter, and weight of the workpiece.

[0014] S2: laser cleaning;

[0015] Laser cleaning of workpieces using laser technology.

[0016] S3: CDA purge;

[0017] Use CDA to purge the workpiece surface until no particles visible to the naked eye remain on the workpiece surface.

[0018] S4: IPA wipe;

[0019] Use a nano dust-free cloth dipped in IPA to wipe the surface of the workpiece. After wiping, use a new nano dust-free cloth to wipe the IPA off the surface of the workpiece.

[0020] S5: high temperature baking;

[0021] The workpiece is baked at high temperature, and the baked workpiece is naturally cooled to 40-60℃ and then taken out and called the cleaned workpiece.

[0022] S6: Measure whether the workpiece is qualified.

[0023] Furthermore, during the laser cleaning, the laser equipment is first turned on and the parameters are set. After the settings, the workpiece to be tested is taken out for testing. After the test is passed, the equipment is turned off and put into standby. The appearance of the workpiece is self-inspected. After the self-inspection is normal, the surface is wiped with a dust-free cloth, and the workpiece is placed in the laser equipment slot. The laser equipment is turned on for operation. After the operation is completed, the laser equipment is turned off, the workpiece is taken out, and the appearance is inspected.

[0024] Furthermore, the measurement items in S6 are as follows:

[0025] Appearance: Use a flashlight to check if there are any new scratches or bumps on the workpiece, and visually check if there are no obvious scratches on the surface of the workpiece to determine that it is qualified.

[0026] Resistance: Use a multimeter to measure the resistance of the workpiece. Each point must be less than 1Ω to be considered qualified.

[0027] Weight loss: Use a balance to measure the weight of the workpiece; it is considered qualified when the weight of the workpiece when it is received - the weight of the workpiece after cleaning is less than 2g.

[0028] Diameter loss: Measure the diameter with a vernier caliper. The workpiece is qualified when the diameter of the incoming workpiece minus the diameter of the workpiece after cleaning is less than 0.02mm.

[0029] EDS: The workpiece is inspected by EDS and is considered qualified if there are no other metal impurities except C and O.

[0030] Furthermore, the laser process parameter test in S2 is divided into two types of tests: removal capability test and removal uniformity test.

[0031] Furthermore, the laser removal ability test includes the following:

[0032] The test height and laser energy parameters are set for testing, and the removal ability is detected using EDS and element residue as detection indicators.

[0033] Furthermore, the laser film removal uniformity test includes the following:

[0034] After completing the laser removal ability test, the laser film removal uniformity test is carried out. The laser energy and height are set, and the laser gun head movement speed parameters and workpiece rotation speed parameters are set for testing. The workpiece resistance, roughness, weight loss, diameter loss and appearance are used as effect evaluation values ​​for testing.

[0035] Furthermore, the baking time in S5 is 4 to 6 hours, and the baking temperature is 160 to 200°C.

[0036] Furthermore, the height was set at 8-10 mm and the laser energy was set at 60-80 kHz as the laser parameters for the removal ability test.

[0037] Furthermore, the laser gun head moving speed of 5 cm / min and the workpiece rotation speed of 20-30 r / min were set as the laser parameters for the laser film removal uniformity test.

[0038] The laser process for automatically removing the film layer of a graphite cylindrical component proposed by the present invention can bring the following beneficial effects:

[0039] 1. The laser process of the present invention can maintain the substrate size and morphology of the workpiece when removing the film layer of the graphite cylindrical component. By optimizing the mechanical motion parameters, it can reduce the diameter loss and weight loss, which is better than the traditional sandblasting process;

[0040] 2. The laser process of the present invention has been tested and found to be able to completely remove impurities at a height of 8-10 cm and a laser energy of 60-80 kHz. EDS verification shows that only C / O elements remain, eliminating metal contamination such as Na / Al / Si, and can accurately remove the film layer with zero metal residue;

[0041] 3. The surface roughness of the graphite cylindrical parts after removing the film layer of the laser process of the present invention is only 1 / 3 of that of the sandblasting process; the resistance stability is significantly lower than that of the sandblasting process, which can improve the surface quality and electrical performance of the graphite cylindrical parts

[0042] 4. The laser process of the present invention establishes a two-level testing system: the removal ability test determines the energy / height window; the uniformity test is linked to the movement speed / rotation speed to achieve uniform treatment of the entire surface. The parameters can be reproduced, reducing manual intervention, making the laser process quantifiable and automated. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0044] Figure 1-9 These are the EDS test schematics for the laser removal capability test schemes 1-9 of the present invention.

[0045] Figure 10 Schematic diagram of the resistance of the workpiece in laser film removal uniformity test schemes 1-9 of the present invention.

[0046] Figure 11 Schematic diagram of the roughness of the workpiece in laser film removal uniformity test schemes 1-9 of the present invention.

[0047] Figure 12 Schematic diagram of the weight loss of the workpiece in laser film removal uniformity test schemes 1-9 of the present invention.

[0048] Figure 13 Schematic diagram of the diameter loss of a workpiece in laser film removal uniformity test schemes 1-9 of the present invention.

[0049] Figure 14 This is a schematic diagram of the EDS test structure in the laser process of the present invention.

[0050] Figure 15 This is a schematic diagram of the EDS test structure in the sandblasting process of the present invention. DETAILED DESCRIPTION

[0051] In order to more clearly illustrate the overall concept of the present invention, a detailed description is given below in an exemplary manner in conjunction with the accompanying drawings.

[0052] An embodiment of the present invention provides a laser process for automatically removing a film layer from a graphite cylindrical component. The laser process includes the following steps:

[0053] S1: Incoming material inspection;

[0054] The appearance of the workpiece (graphite cylindrical component) is inspected using a flashlight, and any abnormalities such as bumps and scratches are recorded. The resistance, EDS (energy dispersive X-ray spectroscopy), diameter, and weight of the workpiece are measured and recorded.

[0055] S2: laser cleaning;

[0056] Use laser technology to clean the workpiece. First, turn on the laser equipment and set the parameters. After setting, take out the workpiece to be tested for testing. After the test is passed, turn off the equipment and put it aside for use. Perform a self-inspection on the appearance of the workpiece. If there is no abnormality in the self-inspection, wipe the surface with a dust-free cloth, put it into the equipment slot, turn on the laser equipment to operate, turn off the laser equipment after the operation is completed, take out the workpiece, and inspect the appearance.

[0057] S3: CDA (air) purge;

[0058] Use CDA to purge the workpiece surface until no particles visible to the naked eye remain on the workpiece surface.

[0059] S4: IPA (absolute alcohol) wipe;

[0060] Use a nano dust-free cloth dipped in IPA to wipe the surface of the workpiece. After wiping, use a new nano dust-free cloth to wipe the IPA off the surface of the workpiece.

[0061] S5: high temperature baking;

[0062] The workpiece is baked at high temperature for 4 to 6 hours at a temperature of 160 to 200°C. The workpiece is naturally cooled to 40 to 60°C and then taken out to be called a cleaned workpiece.

[0063] S6: Measure whether the workpiece is qualified; the measurement items are as follows:

[0064] Appearance: Use a flashlight to check if there are any new scratches or bumps on the workpiece, and visually check if there are no obvious scratches on the surface of the workpiece to determine that it is qualified.

[0065] Resistance: Use a multimeter to measure the resistance of the workpiece. Each point must be less than 1Ω to be considered qualified.

[0066] Weight loss: Use a balance to measure the weight of the workpiece; it is considered qualified when the weight of the workpiece when it is received - the weight of the workpiece after cleaning is less than 2g.

[0067] Diameter loss: Measure the diameter with a vernier caliper. The workpiece is qualified when the diameter of the incoming workpiece minus the diameter of the workpiece after cleaning is less than 0.02mm.

[0068] EDS: The workpiece is inspected by EDS and is considered qualified if there are no other metal impurities except C (carbon) and O (oxygen).

[0069] The laser process parameter tests in S2 can be divided into two categories: laser removal capability test and laser film removal uniformity test. The former is to adjust the laser energy and height (laser head distance from the workpiece) to adjust the optimal laser energy parameters for film removal; the latter is to adjust the auxiliary mechanical operation speed under the premise of optimal energy to achieve the best removal effect in various areas of the workpiece.

[0070] Laser removal capability tests include the following:

[0071] Set multiple test heights as parameters and conduct cross-tests with multiple laser energy parameters. The removal capability is measured using EDS element residue as the detection indicator.

[0072] To optimize laser removal performance, this example used test heights of 8, 10, and 12 cm, and laser energy parameters of 40, 60, and 80 kHz for cross-testing. EDS and elemental residue were used as indicators of laser removal performance. Table 1 shows the test scenarios and test data.

[0073] Table 1: Laser removal ability test parameters

[0074]

[0075] The EDS results in Table 1 show that a laser height of 8 to 10 mm and a laser energy of 60 to 80 kHz can effectively remove deposits from the graphite rod without any contamination from other elements. Therefore, the laser parameters for the removal capability test were set at a height of 8 to 10 mm and a laser energy of 60 to 80 kHz, which were then used in subsequent steps.

[0076] Laser film removal uniformity testing includes the following:

[0077] On the basis of completing the laser removal ability test, the laser film removal uniformity test is carried out. On the basis of completing the laser removal ability test, the laser film removal uniformity test is carried out. The laser energy and height are set, and the laser gun head movement speed parameters and the workpiece rotation speed parameters are set for testing. The resistance, roughness, weight loss, diameter loss and appearance of the workpiece are used as the effect evaluation values ​​for testing.

[0078] In this embodiment, the laser energy is set at 60kHz and the height is set at 10cm. The uniformity of laser film removal is related to the speed of the laser gun head in mechanical operation and the rotation speed of the workpiece. The laser gun head speed is set to 3cm / min; 5cm / min; 8cm / min; the workpiece rotation speed parameter is set to 20r / min; 30r / min; 40r / min for cross-testing. The specific scheme and data are shown in Table 2 and Figure 10-13 As shown:

[0079] Table 2: Laser film removal uniformity test parameters

[0080]

[0081] According to the data in Table 1 and Figure 10-13 It can be seen that when the resistance is controlled within 1Ω, schemes 8 and 9 do not meet the requirements; when the roughness is controlled within 1um, schemes 6, 7, 8 and 9 do not meet the requirements; when the weight loss is controlled within 2g, schemes 1 and 2 do not meet the requirements; when the diameter loss is controlled within 0.02mm, schemes 1, 2 and 3 do not meet the requirements; and the appearance of all schemes meets the requirements; combined with the parameter data and internal control indicators, schemes 4 and 5 meet the test requirements, so the laser gun head movement speed of 5cm / min and the workpiece rotation speed of 20~30r / min are set as the laser parameters for the laser film removal uniformity test, and will be applied in subsequent steps.

[0082] Comparison between laser process and sandblasting process:

[0083] The parameters of the workpiece cleaning process using laser technology are compared with those of the traditional sandblasting process. The laser process adopts a height of 8cm, a laser capacity of 60KHZ, a laser gun head moving speed of 5cm / min; and a workpiece rotation speed of 20r / min.

[0084] Table 3: Comparison of laser and sandblasting process parameters

[0085]

[0086] As can be seen from Table 3, except for EDS, all parameters of the laser process are better than those of the sandblasting process; therefore, the use of laser cleaning process is a development need and also the direction of innovative technology.

[0087] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

[0088] The foregoing is merely an embodiment of the present invention and is not intended to limit the present invention. It will be apparent to those skilled in the art that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are intended to be included within the scope of the claims of the present invention.

Claims

1. A laser process for automatically removing the film layer of a graphite cylindrical component, characterized in that: The laser process includes the following steps: S1: Incoming material inspection; Use a flashlight to inspect the appearance of the workpiece, record any abnormalities such as bumps and scratches, and measure and record the resistance, EDS, diameter, and weight of the workpiece; S2: laser cleaning; Laser cleaning of workpieces using laser technology; S3: CDA purge; Use CDA to purge the workpiece surface until no visible particles remain on the workpiece surface; S4: IPA wipe; Use a nano dust-free cloth dipped in IPA to wipe the surface of the workpiece. After wiping, use a new nano dust-free cloth to dry the IPA on the surface of the workpiece. S5: high temperature baking; The workpiece is baked at high temperature, and the workpiece is taken out after natural cooling to 40-60℃ and is called the cleaned workpiece; S6: Measure whether the workpiece is qualified.

2. The laser process for automatically removing the film layer of a graphite cylindrical component according to claim 1, characterized in that: During the laser cleaning, first turn on the laser equipment and set the parameters. After setting, take out the workpiece to be tested for testing. After the test is passed, turn off the equipment and put it aside for use. Perform a self-inspection on the appearance of the workpiece. After the self-inspection is normal, wipe the surface with a dust-free cloth, put it into the laser equipment slot, turn on the laser equipment to operate, turn off the laser equipment after the operation is completed, take out the workpiece, and inspect the appearance.

3. The laser process for automatically removing the film layer of a graphite cylindrical component according to claim 2, characterized in that: The measurement items in S6 are as follows: Appearance: Use a flashlight to check if there are any new scratches or dents on the workpiece, and visually check if there are no obvious scratches on the surface of the workpiece to determine that it is qualified; Resistance: Use a multimeter to measure the resistance of the workpiece. Each point must be less than 1Ω to be considered qualified. Weight loss: Use a balance to measure the weight of the workpiece; it is considered qualified when the weight of the workpiece upon delivery minus the weight of the workpiece after cleaning is less than 2g; Diameter loss: Use a vernier caliper to measure the diameter. If the diameter of the workpiece at the time of delivery minus the diameter of the workpiece after cleaning is less than 0.02mm, it is considered qualified. EDS: The workpiece is inspected by EDS and is considered qualified if there are no other metal impurities except C and O.

4. The laser process for automatically removing the film layer of a graphite cylindrical component according to claim 3, characterized in that: The laser process parameter test in S2 is divided into two types of tests: removal capability test and removal uniformity test.

5. The laser process for automatically removing the film layer of a graphite cylindrical component according to claim 4, characterized in that: The laser removal capability test includes the following: The test height and laser energy parameters are set for testing, and the removal ability is detected using EDS and element residue as detection indicators.

6. The laser process for automatically removing the film layer of a graphite cylindrical component according to claim 5, characterized in that: The laser film removal uniformity test includes the following: After completing the laser removal ability test, the laser film removal uniformity test is carried out. The laser energy and height are set, and the laser gun head movement speed parameters and workpiece rotation speed parameters are set for testing. The workpiece resistance, roughness, weight loss, diameter loss and appearance are used as effect evaluation values ​​for testing.

7. The laser process for automatically removing the film layer of a graphite cylindrical component according to claim 6, characterized in that: The baking time in S5 is 4 to 6 hours, and the baking temperature is 160 to 200°C.

8. The laser process for automatically removing the film layer of a graphite cylindrical component according to claim 7, characterized in that: The laser parameters for the removal ability test were set at a height of 8 to 10 mm and a laser energy of 60 to 80 kHz.

9. The laser process for automatically removing the film layer of a graphite cylindrical component according to claim 8, characterized in that: The laser parameters for the laser film removal uniformity test were set at a laser gun head speed of 5 cm / min and a workpiece speed of 20-30 r / min.

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