A raw material pretreatment device and method for granulating yttrium oxide in a dry etching device

Abstract

The application discloses a raw material pretreatment device and method for granulating yttrium oxide in a dry etching device, and belongs to the technical field of semiconductor material preparation. The device comprises a feeding unit, a multi-stage screening unit, an ultrasonic cleaning unit, a centrifugal dehydration unit, a drying unit, an inert gas protection system, an online particle size monitoring module, a PLC control system and a discharging unit. The method comprises the steps of multi-stage screening, countercurrent ultrasonic cleaning, centrifugal dehydration, fluidized drying, online particle size feedback and sealed discharging. Through integrated design and closed-loop control, the application realizes efficient, clean and low-damage pretreatment of yttrium oxide crystal particles, ensures that the particle size of the output raw material is strictly locked in 0.5-3mm, the surface is clean, and the crystal lattice is complete, significantly improves the batch stability and plasma resistance of the subsequent granulated yttrium oxide, and meets the manufacturing requirements of high-end semiconductor etching device parts.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor material preparation technology, specifically relating to a raw material pretreatment device and method for granulation of yttrium oxide in dry etching equipment. It is particularly suitable for automated and closed pretreatment of high-purity, high-crystallinity yttrium oxide crystal particles, providing raw materials with uniform particle size, clean surface, and complete crystal lattice for subsequent granulation processes. Background Technology

[0002] As semiconductor chip manufacturing processes continue to shrink, the performance requirements for plasma-resistant components within the etching chamber of dry etching equipment are becoming increasingly stringent. Yttrium oxide (Y₂O₃), due to its extremely high plasma resistance, thermal stability, and chemical inertness, is widely used in the manufacture of components such as focusing rings, nozzles, and gaskets. Industrial production of yttrium oxide granulated powder typically starts with crystalline bulk materials and involves multiple processes including raw material pretreatment, calcination, crushing, granulation, and consolidation. Among these, raw material pretreatment is the first hurdle determining the quality of the final product, directly affecting the purity, particle size distribution, surface condition, and lattice integrity of the raw material.

[0003] Existing pretreatment technologies often employ independent, discontinuous combinations of equipment, such as vibrating screens, washing tanks, and drying ovens. Materials are susceptible to secondary contamination during transfer between different devices, and particle collisions can lead to breakage and microcracks, compromising crystal integrity. Furthermore, traditional processes lack online particle size monitoring and adaptive control, resulting in poor particle size consistency, high fine powder content, and low yield in subsequent granulation. In addition, the washing process consumes a large amount of water, and the untreated wastewater is not reused, which contradicts the trend of green manufacturing. Therefore, there is an urgent need to develop an integrated, automated, and low-damage raw material pretreatment equipment and method to address these problems. Summary of the Invention

[0004] I. Purpose of the Invention

[0005] The present invention aims to overcome the shortcomings of the prior art and provide a raw material pretreatment device and method for yttrium oxide granulation in dry etching equipment, so as to achieve efficient, clean and low-damage pretreatment of yttrium oxide crystal particles, provide stable raw materials for the subsequent two-stage sintering and granulation processes, and reduce manual intervention and improve batch consistency.

[0006] II. Technical Solution

[0007] This invention is achieved through the following technical solution:

[0008] A raw material pretreatment device for granulation of yttrium oxide in dry etching equipment, characterized in that it comprises:

[0009] Feeding unit: includes a hopper and a vibrating feeder, used to uniformly feed large crystalline yttrium oxide blocks into the next unit;

[0010] Multi-stage screening unit: includes at least two layers of vibrating screens with different apertures. The upper screen retains particles larger than 3mm and returns them for crushing. The lower screen collects target particle size particles of 0.5mm to 3mm. The undersize material is fine powder.

[0011] Ultrasonic cleaning unit: includes a closed cleaning tank, ultrasonic generator, deionized water circulation system and online turbidimeter, used to deeply clean the screened particles and remove surface dust;

[0012] Centrifugal dewatering unit: includes a variable frequency centrifugal dewatering machine, connected to the outlet of the washing tank, for quickly removing adsorbed water from the surface of particles;

[0013] Drying unit: including fluidized bed dryer or belt dryer, equipped with hot air circulation, humidity sensor and temperature controller, used to dry dehydrated particles to constant weight;

[0014] Inert gas protection system: It connects all units and fills the equipment with nitrogen or argon gas to prevent particles from oxidizing or getting damp during high temperature or high speed movement;

[0015] Online particle size monitoring module: including a laser particle size analyzer or dynamic image analyzer installed at the outlet of the drying unit, used to monitor the particle size distribution of the pretreated raw material in real time and provide feedback to adjust the screening unit and feeding speed;

[0016] PLC control system: It is electrically connected to the feeding unit, screening unit, washing unit, dewatering unit, drying unit and particle size monitoring module respectively, and automatically adjusts the operating status of each unit according to preset parameters and real-time monitoring data;

[0017] Discharge unit: includes a sealed storage tank and an automatic packaging device, used to collect and package pre-treated qualified raw materials.

[0018] The raw material pretreatment method based on the aforementioned equipment includes the following steps:

[0019] Step a: Multi-stage screening – Yttrium oxide crystal particles are fed into the feeding unit and then into the multi-stage screening unit via a vibrating feeder. The upper screen has a mesh size of 3mm, and the lower screen has a mesh size of 0.5mm. Particles in the 0.5mm to 3mm size are cut off and sent to the ultrasonic cleaning unit. Particles larger than 3mm are crushed in a bypass and then screened again. Fine powder smaller than 0.5mm is collected for other uses.

[0020] Step b: Countercurrent ultrasonic cleaning – In a closed cleaning tank, the particles and deionized water flow in opposite directions. At the same time, the ultrasonic generator is turned on with a frequency of 20-40kHz and a power density of 0.3-0.8W / cm². The cleaning time is 5-15 minutes. During the cleaning process, the circulating water is monitored by an online turbidity meter. When the turbidity is higher than the set threshold, fresh deionized water is automatically added and some cleaning waste liquid is discharged.

[0021] Step c: Centrifugal dewatering – The washed granular slurry is pumped into a centrifugal dewatering machine and dewatered at a speed of 800-1500 r / min for 2-5 minutes. After dewatering, the surface moisture content of the granules is less than 3%.

[0022] Step d: Fluidized bed drying – Dehydrated particles enter a fluidized bed dryer and are introduced with HEPA-filtered hot nitrogen gas. The inlet temperature is 90–120°C, and the drying time is 20–40 minutes. The material is discharged when the outlet gas dew point is below -20°C, controlled by a humidity sensor.

[0023] Step e: Online particle size detection and feedback – After drying, the particles flow through the detection area of ​​the laser particle size analyzer, and the particle size distribution data is output in real time; if D50 deviates from the target value (1.5~2.0mm) or the fine powder content (<0.5mm) exceeds 3%, the PLC system automatically adjusts the vibration frequency or feeding speed of the screening unit, and triggers screen cleaning if necessary;

[0024] Step f: Inert gas protection and sealed discharge – The entire pretreatment process maintains a slightly positive pressure nitrogen atmosphere inside the equipment, with an oxygen content of less than 100 ppm; the qualified pretreatment particles are sealed under nitrogen protection through the discharge unit to obtain the raw material to be calcined.

[0025] Beneficial effects

[0026] 1. Integrated equipment design: The functions of screening, washing, dewatering, drying, and particle size monitoring are integrated into a closed production line. The material flows automatically under the protection of inert gas throughout the process, eliminating cross-contamination, reducing particle breakage, and maintaining crystal integrity.

[0027] 2. Ultrasonic countercurrent cleaning and circulating water control: Utilizing the ultrasonic cavitation effect, submicron-level dust is efficiently removed from the particle surface. Combined with online turbidity feedback, water consumption is significantly reduced. After cleaning, the surface cleanliness of the particles can reach the SEMI standard F63-0210 level.

[0028] 3. Online particle size closed-loop control: For the first time, real-time particle size monitoring and PLC self-adjustment are introduced in the pretreatment stage to ensure that the output raw material particle size is strictly locked in the range of 0.5 to 3 mm, and the batch fluctuation is less than ±5%, providing a highly consistent feeding diameter for the subsequent two firing processes.

[0029] 4. Low-damage conveying and drying: Fluidized bed drying is used instead of traditional oven drying, ensuring uniform heating of particles without mechanical compression; all material contact parts are lined with polyurethane or ceramic to avoid metal contamination.

[0030] 5. Data traceability: The PLC system records the pretreatment process parameters for each batch (cleaning turbidity curve, drying temperature curve, particle size distribution trend), meeting the quality traceability requirements of semiconductor materials. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention; Detailed Implementation

[0033] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0034] Example 1

[0035] The equipment and method of this invention were used to pretreat crystalline yttrium oxide granules (purity 99.99%, initial particle size 0.1–10 mm) provided by a manufacturer. Equipment parameters: upper sieve 3 mm, lower sieve 0.5 mm; ultrasonic cleaning frequency 28 kHz, power density 0.5 W / cm², cleaning time 12 minutes; initial conductivity of deionized water 0.5 μS / cm; centrifugal dehydration speed 1200 r / min, dehydration time 3 minutes; fluidized bed drying inlet temperature 105℃, hot nitrogen flow rate 50 m³ / h, drying time 30 minutes; online laser particle size analyzer (MalvernInSite model), detection frequency 1 time / second. Sample testing after pretreatment: target particle size 0.5–3 mm yield 94.5%, D50 = 1.82 mm, fine powder content less than 0.5 mm 1.8%; no adhering dust observed on the particle surface by SEM, and surface carbon contamination detected by XPS was below the detection limit; oxygen content remained <50 ppm throughout the entire treatment process under nitrogen protection. The raw materials to be fired were directly used in the subsequent first stage firing, and the resulting granulated yttrium oxide final product had a purity of 99.98%, and the plasma corrosion rate was reduced by 22% compared with conventional pretreated raw materials.

[0036] Example 2

[0037] The procedure was basically the same as in Example 1, but the ultrasonic cleaning time was adjusted to 8 minutes and the drying temperature was increased to 115°C. After pretreatment, the target particle size yield was 93.2%, the fine powder content was 2.1%, and D50 was 1.75 mm. This indicates that stable pretreatment results can be achieved within a certain range of parameters.

[0038] Comparative Example 1

[0039] Traditional independent equipment was used: manual sieving, open washing tank, and forced-air drying oven, with the material exposed to air during transfer. The results showed that the fine powder content after pretreatment was as high as 8.7%, and there was obvious recontamination on the surface. The strength of the granulated particles decreased after subsequent firing, and pitting corrosion was observed in plasma testing.

[0040] Industrial Application Prospects

[0041] The raw material pretreatment equipment and method provided by this invention can be seamlessly integrated with existing yttrium oxide granulation production lines, and are particularly suitable for the manufacturing of high-end components for dry etching equipment used in 12-inch and larger wafer fabrication. The raw materials pretreated by this invention have intact crystal lattices, concentrated particle sizes, and clean surfaces, which can significantly improve the batch stability and plasma resistance of the final granulated yttrium oxide, and have broad prospects for industrial applications.

Claims

1. A raw material pretreatment device for granulation of yttrium oxide in dry etching equipment, characterized in that, include: Feeding unit: includes a hopper and a vibrating feeder; Multi-stage screening unit: includes at least two layers of vibrating screens with different apertures, the upper screen aperture is 3mm and the lower screen aperture is 0.5mm, used to cut out target particle size of 0.5mm to 3mm; Ultrasonic cleaning unit: includes a sealed cleaning tank, an ultrasonic generator, a deionized water circulation system, and an online turbidimeter; Centrifugal dehydration unit: including a variable frequency centrifugal dehydrator; Drying unit: including a fluidized bed dryer or a belt dryer, equipped with hot air circulation, humidity sensor and temperature controller; Inert gas protection system: Nitrogen or argon gas is introduced into the equipment to maintain a slight positive pressure; Online particle size monitoring module: including laser particle size analyzer or dynamic image analyzer; PLC control system: It is electrically connected to each of the aforementioned units and automatically adjusts according to preset parameters and real-time monitoring data; Discharge unit: includes a sealed storage tank and an automatic packaging device.

2. The raw material pretreatment equipment according to claim 1, characterized in that, In the ultrasonic cleaning unit, the ultrasonic frequency is 20-40kHz, the power density is 0.3-0.8W / cm², and the cleaning tank is equipped with a guide plate to make the particles move in a countercurrent.

3. The raw material pretreatment equipment according to claim 1, characterized in that, The moisture content of the particles exiting the centrifugal dehydration unit is less than 3%.

4. The raw material pretreatment equipment according to claim 1, characterized in that, The drying unit uses a fluidized bed dryer, with hot air being HEPA-filtered nitrogen gas at an inlet temperature of 90–120°C. After drying, the particle dew point is below -20°C.

5. The raw material pretreatment equipment according to claim 1, characterized in that, The inert gas protection system keeps the oxygen content inside the equipment below 100ppm, and all material channels are isolated by air curtains.

6. A raw material pretreatment method based on the equipment according to any one of claims 1 to 5, characterized in that... Includes the following steps: Step a: Multi-stage screening – Screen the yttrium oxide crystal particles to obtain particle sizes of 0.5mm to 3mm; Step b: Countercurrent ultrasonic cleaning – Ultrasonic cleaning is performed in a closed cleaning tank, and the cleanliness of the cleaning solution is controlled by an online turbidity meter; Step c: Centrifugation – Dehydrate until the moisture content is below 3%; Step d: Fluidized bed drying – drying to constant weight in a hot nitrogen atmosphere; Step e: Online particle size detection and feedback – Real-time monitoring of particle size distribution; the PLC system adjusts screening and feeding parameters based on the results. Step f: Inert gas protection and sealed discharge – nitrogen protection throughout the process, maintaining a sealed environment during discharge.

7. The raw material pretreatment method according to claim 6, characterized in that, In step b, the cleaning time is 5 to 15 minutes. When the turbidity is higher than the set threshold, fresh deionized water is automatically added.

8. The raw material pretreatment method according to claim 6, characterized in that, In step e, the target particle size range is 0.5–3 mm, the target D50 value is 1.5–2.0 mm, and the upper limit for fine powder content (<0.5 mm) is 3%.

9. The raw material pretreatment method according to claim 6, characterized in that, In step a, particles larger than 3 mm are returned to the sieve after being bypassed and crushed, while fine powder smaller than 0.5 mm is collected separately for the preparation of fine powder for interstitial filling.

10. The raw material pretreatment equipment according to claim 1, characterized in that, The surfaces of components that come into contact with materials are lined with polyurethane, ceramic, or Teflon coatings to prevent metal contamination.

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