Method for replacing dispersion pipe in LPCVD furnace body in high-temperature state
Technical Field
The invention relates to a method for replacing a dispersion pipe in an LPCVD furnace body at a high temperature.
Background
Silicon materials are the main substrate materials for manufacturing very large scale integrated circuits, and with the rapid development of the semiconductor industry, the requirements on equipment are higher and stricter. Maintenance and repair of equipment has also become an important part of the silicon wafer industry. The equipment can be operated more quickly and effectively in the aspect of equipment maintenance, which is one of important ways for improving the yield, because a large amount of polycrystalline silicon is adhered to the surface of a cavity dispersion pipe in the process of depositing the polycrystalline silicon by LPCVD (low pressure chemical vapor deposition), so that large stress is generated, and the stress is gradually increased along with the continuous increase of the thickness of the polycrystalline silicon layer, the dispersion pipe is damaged due to the fact that the dispersion pipe is cooled when the dispersion pipe is used in the middle stage, so that the whole set of dispersion pipe needs to be replaced, the production cost is greatly increased, and the production efficiency is reduced.
The traditional method for replacing the dispersion tube is to slowly cool the dispersion tube from 600 ℃ to room temperature for replacement, wherein the replacement comprises replacing TC, then heating to 600 ℃, and further carrying out process verification and cavity purification, so that the next replacement of one set of dispersion tube needs about 48 hours or even longer, and other dispersion tubes which are not damaged can be damaged in the heating process after the replacement is finished.
Disclosure of Invention
The invention aims to provide a method for replacing a dispersion pipe in an LPCVD furnace body in a high-temperature state, which can effectively improve the replacement efficiency of the dispersion pipe and greatly reduce the replacement cost of the dispersion pipe.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for replacing a dispersion tube in an LPCVD furnace body in a high-temperature state is characterized in that a dispersion tube clamping device is used, the dispersion tube clamping device is provided with two clamping arms, the two clamping arms are hinged to form two clamping front arms and two handheld rear arms, the end parts of the clamping front arms are respectively connected with a clamping head, and the end parts of the handheld rear arms are respectively connected with a handle; the two clamping arms can rotate around the hinged part, and the loosening and the clamping of the clamping heads are controlled according to the lever principle; the method comprises the following steps:
(1) opening the LPCVD furnace, taking out the accessory parts comprising the quartz boat and the base, taking out the damaged dispersion tube from the dispersion tube support frame by using a dispersion tube clamping device, and then reinstalling a new dispersion tube on the dispersion tube support frame by using the dispersion tube clamping device;
(2) adjusting the distance between the dispersion pipe and the furnace tube to enable the dispersion pipe to be tightly attached to the inner pipe;
(3) installing accessory parts comprising a quartz boat and a base, and checking whether the quartz boat rubs with the dispersion tube support frame;
(4) the furnace body is subjected to ultimate vacuum detection and leakage rate detection, and can be directly produced after being confirmed to be correct.
Preferably, the gripping head of the dispersion tube gripper is a movable gripping head, and the gripping head is connected with the gripping forearm through a movable head pin and can move relative to the gripping forearm.
Preferably, the gripping head of the dispersion tube gripper has a dispersion tube fixing portion in contact with the dispersion tube and a gripping head rotating shaft portion pinned to the movable head, and the dispersion tube fixing portion has an opening angle of 120 °.
The invention has the advantages that:
by adopting the method, whether the position of the dispersion tube is correct or not does not need to be noticed when the dispersion tube is taken, when a new dispersion tube is placed, the dispersion tube is clamped by the dispersion tube clamping device and then slowly goes deep into the inner tube of the back sealing furnace, and the dispersion tube is slowly placed on the dispersion tube support frame after the position is adjusted, so that the replacement process is simplified, and the cost and the time are saved.
In order to prevent the dispersion tube (the inner quartz tube and the outer quartz tube) from cracking or breaking due to the cooling of the furnace body, the whole process of replacing the dispersion tube by adopting the method of the invention does not need cooling, and the damage of other dispersion tubes caused by cooling before the service life is reached is avoided.
The invention utilizes the lever principle, the movable clamping head avoids the defect that the traditional lever only bears a little force, and the stability of the dispersion tube clamping device is greatly strengthened.
Drawings
Fig. 1 is a schematic view of the overall structure of the dispersion tube gripper.
Fig. 2 is a schematic structural diagram of a movable clamping head of the dispersion tube clamping device.
Fig. 3 is a schematic structural diagram of a dispersion tube gripper used for gripping the dispersion tube.
Detailed Description
The present invention is further illustrated by the following specific embodiments, which are not meant to limit the scope of the invention.
As shown in figure 1, the method of the invention uses a special dispersion tube gripper designed by the invention, and the dispersion tube gripper is provided with two gripping arms which are hinged to form two gripping front arms 2 and two handheld rear arms 3, wherein the ends of the gripping front arms are respectively connected with a gripping head 1, and the ends of the handheld rear arms are respectively connected with a handle 8; the two gripper arms are pivotable about a hinge point 4, which controls the release and the gripping of the gripper head 1 according to the lever principle. The clamping head 1 of the dispersion tube clamping device is connected with the clamping forearms 2 through movable head pins 9 and can move relative to the clamping forearms, namely the movable clamping head. As shown in fig. 2, the movable gripper head has a dispersion tube fixing portion 11 which is in contact with the dispersion tube and a gripper head rotating shaft portion 12 which is connected to the movable head pin 9; the opening angle of the dispersion tube fixing part 11 is 120 degrees, and the dispersion tube fixing part is designed to be 120 degrees, so that the dispersion tube is convenient to process, and is stressed more uniformly in the clamping process, and the dispersion tube is protected better. The part 12 of the clamping head rotating shaft connected with the movable head pin 9 can rotate around the movable head pin 9, and the main function of the device is to ensure that a dispersion tube can be always kept on the same straight line with the whole dispersion tube clamping device as long as a user clamps and fixes the dispersion tube, so that the user can replace the dispersion tube more conveniently.
As shown in FIG. 3, the process of replacing the dispersion tube in the LPCVD furnace body in a high-temperature state by using the dispersion tube gripper is as follows:
1. when the dispersion tube is damaged, the LPCVD furnace 7 is opened, the quartz boat, the base and the like are removed without cooling, the damaged dispersion tube is taken out by using the dispersion tube clamp designed by the invention, whether the position of the dispersion tube is correct or not is not required to be noticed when the dispersion tube is taken, at the moment, the furnace body is not cooled, the distance from the furnace mouth is required to be noticed, the dispersion tube clamp is correctly used, and a hand holds a handle 8 at the end part of a rear arm held by the dispersion tube; the damaged dispersion tube is taken out and cannot be directly contacted with the damaged dispersion tube by hands, and the damaged dispersion tube is placed at a safe position far away from inflammable substances by using a dispersion tube clamping device.
2. The method comprises the following steps of unsealing a new dispersion tube 6, clamping the bottom of the dispersion tube by using a dispersion tube clamping device, clamping the dispersion tube by using the dispersion tube clamping device, slowly penetrating into an inner tube of a back sealing furnace, slowly placing the dispersion tube on a dispersion tube support frame 5 after adjusting the position, and paying attention to whether the position of the dispersion tube completely falls into a base of the dispersion tube support frame 5. The movable clamping heads 1 are in clearance fit, the direction can be adjusted at will, and the dispersion tube 6 is more conveniently and stably arranged on the dispersion tube support frame 5 in the furnace body again.
3. After the quartz boat and the base are re-installed, vacuum detection is carried out, and production can be continued after the quartz boat and the base are confirmed to be correct.