A method for improving CVD particle defects and contamination defects

Abstract

The present invention relates to the field of mechanical technology. A method for improving CVD particle defects and contamination defects comprises the following steps: Step 1, placing a 6-inch film box in a transfer cleaning basket; the transfer cleaning basket comprises a front side plate and a rear side plate arranged front and back, and the front side plate and the rear side plate are connected by a connecting rod; slots for longitudinally inserting the film box are provided on the inner walls of the front side plate and the rear side plate; the left and right ends of the top of the front side plate and the left and right ends of the top of the rear side plate are detachably connected with a manipulator grabbing rod; Step 2, placing it in a liquid tank of an 8-inch cleaning device; Step 3, washing with pure water for 360S; Step 4, taking it out and putting it in a spin dryer; Step 5, taking it out of the spin dryer; Step 6, taking the 6-inch film box out of the transfer cleaning basket. The present invention avoids defects caused by manual film rewinding by optimizing the pre-CVD cleaning process.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, in particular to a cleaning method. Background Art

[0002] The CVD pre-cleaning process is achieved by a CVD pre-cleaning machine specially designed for cleaning 8-inch wafers. However, when 6-inch wafers need to undergo CVD pre-cleaning, the robot for grabbing the wafer cassette and the cleaning tank base of the cleaning machine are both compatible with the structure of the 8-inch wafer cassette. Therefore, the cassette containing 6-inch wafers cannot be directly placed into the CVD pre-cleaning machine specially designed for cleaning 8-inch wafers.

[0003] In traditional operations, the 6-inch wafers that need to be cleaned are first poured into a special cassette, and then placed into an 8-inch wafer cleaning machine for pre-CVD cleaning; after cleaning, the 6-inch wafers need to be poured into the 6-inch special cassette again. The 6-inch special cassette needs to be cleaned with pure water and dried in advance by the operator before it can be sent to the CVD machine for processing.

[0004] The above operation process has the following defects:

[0005] 1) The 6-inch wafer cassette needs to be manually cleaned with pure water and manually dried. If the cassette is not cleaned thoroughly, particles and contaminants (including metal contamination) are likely to remain in the grooves. Using them to hold cleaned wafers can easily bring contaminants to the wafer surface, causing particle defects and contamination defects on the wafers after processing.

[0006] 2) Because 8-inch cleaning machines cannot clean 6-inch cassettes containing 6-inch wafers, the 6-inch wafers currently need to be transferred to a transfer cassette. After cleaning, the 6-inch wafers are manually transferred to a dedicated 6-inch cassette. During this manual rewinding step, due to the large amount of particles and contaminants in the air, on the rewinder, and on people's sleeves and gloves, the wafer surface can easily become contaminated, ultimately leading to particle and contamination defects in the wafers after processing.

[0007] 3) Converting film boxes back and forth (rewinding the film), manually brushing the 6-inch film boxes, and manually drying the 6-inch film boxes waste a lot of manpower and take up a long working time. Summary of the Invention

[0008] In response to the problems existing in the prior art, the present invention provides a method for improving CVD particle defects and contamination defects, which has solved at least one of the above technical problems.

[0009] The technical solution of the present invention is: a method for improving CVD particle defects and contamination defects, characterized by comprising the following steps:

[0010] Step 1: Place the 6-inch film box into the transfer cleaning basket;

[0011] The transfer cleaning basket includes a front side plate and a rear side plate arranged in front and back, and the front side plate and the rear side plate are connected by a connecting rod;

[0012] The inner walls of the front side plate and the rear side plate are provided with slots for longitudinally inserting the film cassette;

[0013] The left and right ends of the top of the front side plate and the left and right ends of the top of the rear side plate are detachably connected with a manipulator grabbing rod;

[0014] Step 2: The robot grabs the transfer cleaning basket and places it in the 8-inch cleaning equipment's liquid tank. The cleaning solution in the tank includes ammonia and hydrogen peroxide, and the cleaning time is 360 seconds.

[0015] Step 3: The robot grabs the transfer cleaning basket and places it in the cleaning tank of the 8-inch cleaning equipment. It is then cleaned with pure water for 360 seconds.

[0016] Step 4: The robot grabs the transfer cleaning flower basket. The robot grabs the robot grabbing rod and takes the transfer cleaning flower basket out of the 8-inch cleaning device and puts it into the dryer. The speed is 700 RPM and the drying time is 300 seconds.

[0017] Step 5: The robot grabs the transfer cleaning flower basket with a robot grabbing rod to take the transfer cleaning flower basket out of the dryer;

[0018] Step 6: Take out the 6-inch film box from the transfer cleaning basket.

[0019] By optimizing the pre-CVD cleaning process, this invention allows 6-inch film cassettes to be cleaned directly using an 8-inch cleaning machine, eliminating the need for frequent manual cleaning of the cassettes and saving manpower, material resources, and time. This also eliminates defects caused by manual film rewinding and incomplete cleaning of the 6-inch film cassettes. CVD particle and contamination defects are significantly improved, with the particle defect rate controlled within 0.5% and the contamination defect rate within 0.01%.

[0020] More preferably, it further includes a limiting support sheet;

[0021] The bottoms of the front side plate and the rear side plate are provided with downwardly extending extension portions, and the extension portions are detachably connected to the position-limiting support pieces.

[0022] It is convenient to ensure the placement effect in the cleaning tank and the dryer.

[0023] Further preferably, the temperature of the cleaning solution in step 2 is 65°C;

[0024] In step 3, the water temperature is room temperature.

[0025] More preferably, after step six, a CVD process is performed.

[0026] Further preferably, the manipulator grabbing rod comprises a horizontally arranged crossbar portion and a vertically arranged vertical rod portion, and the top of the vertical rod portion is fixedly connected to the top of the crossbar portion;

[0027] The horizontal rod portion is formed by a mounting portion and a clamping portion which are adjacently arranged through the vertical rod portion;

[0028] The tops of the front side plate and the rear side plate are in close contact with the mounting portion of the manipulator grabbing rod and are connected by screws;

[0029] The inner sides of the front side plate and the rear side plate are in close contact with the vertical rod portion of the manipulator grabbing rod and are connected via screws.

[0030] Further preferably, a limiting groove is provided at the bottom of the clamping portion.

[0031] Further preferably, the front side plate and the rear side plate are both provided with countersunk holes for embedding screws, and the front and rear ends of the connecting rod are detachably connected to the front side plate and the rear side plate respectively by screws.

[0032] Easy to assemble.

[0033] Further preferably, a notch is provided in the center of the bottom of the front side plate and the rear side plate.

[0034] Easy to clean.

[0035] Further preferably, water holes are provided on the front side plate and the rear side plate.

[0036] Further preferably, the front side panel and the rear side panel are arranged in a front-to-back mirror-symmetrical manner;

[0037] The left and right sides of the front side plate are provided with protrusions protruding backwards;

[0038] The protrusion is provided with a step protruding backwards, and the step is connected to the connecting rod.

[0039] The inner sides of the steps on the left and right sides are used to contact the left and right sides of the film box. The protrusions are used to provide space for the reinforcing ribs on the front and back sides of the film box. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural diagram of a transfer cleaning flower basket in specific embodiment 1 of the present invention.

[0041] In the figure: 1 is the front side plate, 2 is the rear side plate, 3 is the manipulator grabbing rod, 4 is the connecting rod, and 5 is the limiting support plate. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the accompanying drawings.

[0043] See also Figure 1 Specific embodiment 1, a method for improving CVD particle defects and contamination defects, comprising the following steps:

[0044] Step 1: Place the 6-inch film box into the transfer cleaning basket;

[0045] Step 2: The robot grabs the transfer cleaning basket and places it in the 8-inch cleaning equipment's liquid tank. The liquid in the tank contains a cleaning solution with a concentration ratio of ammonia: hydrogen peroxide: water = 1:4:20, and the cleaning time is 360 seconds.

[0046] Step 3: The robot grabs the transfer cleaning basket and places it in the cleaning tank of the 8-inch cleaning equipment. It is then cleaned with pure water for 360 seconds.

[0047] Step 4: The robot grabs the transfer cleaning flower basket. The robot grabbing rod 3 takes the transfer cleaning flower basket out of the 8-inch cleaning device and puts it into the dryer. The speed is 700 RPM and the drying time is 300 seconds.

[0048] Step 5: The robot grabs the transfer cleaning flower basket using the robot grabbing rod 3 to take the transfer cleaning flower basket out of the dryer;

[0049] Step 6: Take out the 6-inch film box from the transfer cleaning basket.

[0050] This invention avoids problems caused by wafer rewinding by optimizing the pre-CVD cleaning process. CVD particle and contamination defects are significantly improved. The particle defect rate is controlled within 0.5%, and the contamination defect rate is controlled within 0.01%. Conventional particle defect rates are controlled at approximately 1.8%, and the contamination defect rate is around 1.2%.

[0051] The temperature of the cleaning solution in step 2 is 65°C;

[0052] In step 3, the water temperature is room temperature.

[0053] After step six, a CVD process is performed.

[0054] The transfer cleaning basket includes a front side panel 1 and a rear side panel 2, which are connected by a connecting rod 4. Slots for inserting film cassettes longitudinally are provided on the inner walls of the front side panel 1 and the rear side panel 2. Robot gripper rods 3 are detachably connected to the left and right ends of the top of the front side panel 1 and the left and right ends of the top of the rear side panel 2. A limiting support plate 5 is also included. The bottoms of the front side panel 1 and the rear side panel 2 are provided with downwardly extending extensions, which are detachably connected to the limiting support plate. This facilitates the placement of the basket in the washing tank and the spin dryer.

[0055] The manipulator gripping rod 3 includes a horizontally arranged crossbar portion and a vertically arranged vertical rod portion, the top of the vertical rod portion being fixedly connected to the top of the crossbar portion; the crossbar portion is divided into an adjacent mounting portion and a clamping portion through the vertical rod portion; the tops of the front side plate 1 and the rear side plate 2 are in close contact with the mounting portion of the manipulator gripping rod 3 and are connected by screws; the inner sides of the front side plate 1 and the rear side plate 2 are in close contact with the vertical rod portion of the manipulator gripping rod 3 and are connected by screws. A limiting groove is defined at the bottom of the clamping portion.

[0056] The front side panel 1 and the rear side panel 2 are both provided with countersunk holes for embedding screws, and the front and rear ends of the connecting rod 4 are detachably connected to the front side panel 1 and the rear side panel 2 respectively by screws. This facilitates assembly. A notch is provided in the center of the bottom of the front side panel 1 and the rear side panel 2. This facilitates cleaning. Water-permeable holes are provided on the front side panel 1 and the rear side panel 2. The front side panel 1 and the rear side panel 2 are arranged in a mirror-symmetrical manner front and back; the left and right sides of the front side panel 1 are provided with protrusions protruding backwards; the protrusions are provided with steps protruding backwards, and the steps are connected to the connecting rod 4. The inner sides of the steps on the left and right sides are used to contact the left and right sides of the film box. The protrusions are used to provide space for the reinforcing ribs on the front and back sides of the film box.

[0057] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for improving CVD particle defects and contamination defects, characterized in that: The steps include: Step 1: Place the 6-inch film box into the transfer cleaning basket; The transfer cleaning basket includes a front side plate and a rear side plate arranged in front and back, and the front side plate and the rear side plate are connected by a connecting rod; The inner walls of the front side plate and the rear side plate are provided with slots for longitudinally inserting a 6-inch film box; The left and right ends of the top of the front side plate and the left and right ends of the top of the rear side plate are detachably connected with a manipulator grabbing rod; The front side panels and the rear side panels are arranged in a front-to-back mirror-symmetrical manner; The left and right sides of the front side plate are provided with protrusions protruding backwards; The protrusion is provided with a step protruding backward, and the step is connected to the connecting rod; the inner sides of the steps on the left and right sides are used to contact the left and right sides of the film box; The protrusions are used to provide space for the reinforcing ribs on the front and back sides of the cassette; The manipulator grabbing rod comprises a horizontally arranged crossbar portion and a vertically arranged vertical rod portion, and the top of the vertical rod portion is fixedly connected to the top of the crossbar portion; The horizontal rod portion is formed by a mounting portion and a clamping portion which are adjacently arranged through the vertical rod portion; The tops of the front side plate and the rear side plate are in close contact with the mounting portion of the manipulator grabbing rod and are connected by screws; The inner sides of the front side plate and the rear side plate are in close contact with the vertical rod portion of the manipulator grabbing rod and are connected by screws; Step 2: The robot grabs the transfer cleaning basket and places it in the liquid tank of the 8-inch cleaning equipment. The cleaning solution in the liquid tank includes hydrogen peroxide and ammonia. The cleaning time is 360 seconds. Step 3: The robot grabs the transfer cleaning basket and places it in the cleaning tank of the 8-inch cleaning equipment. It is then cleaned with pure water for 360 seconds. Step 4: The robot grabs the transfer cleaning flower basket. The robot grabs the robot grabbing rod and takes the transfer cleaning flower basket out of the 8-inch cleaning device and puts it into the spin dryer. The spin dryer is spun at a speed of 700 RPM for 300 seconds. Step 5: The robot grabs the transfer cleaning flower basket with a robot grabbing rod to take the transfer cleaning flower basket out of the dryer; Step 6: Take out the 6-inch film box from the transfer cleaning basket; After step six, a CVD process is performed.

2. The method for improving CVD particle defects and contamination defects according to claim 1, wherein: Also includes a limiting support piece; The bottoms of the front side plate and the rear side plate are provided with downwardly extending extension portions, and the extension portions are detachably connected to the position-limiting support pieces.

3. The method for improving CVD particle defects and contamination defects according to claim 1, wherein: The temperature of the cleaning solution in step 2 is 65°C; In step 3, the water temperature is room temperature.

4. The method for improving CVD particle defects and contamination defects according to claim 1, wherein: A limiting groove is provided at the bottom of the clamping portion.

5. The method for improving CVD particle defects and contamination defects according to claim 1, wherein: The front side plate and the rear side plate are both provided with countersunk holes for embedding screws, and the front and rear ends of the connecting rod are detachably connected to the front side plate and the rear side plate respectively by screws.

6. The method for improving CVD particle defects and contamination defects according to claim 1, wherein: A notch is formed in the center of the bottom of the front side plate and the rear side plate.

7. The method for improving CVD particle defects and contamination defects according to claim 1, wherein: The front side plate and the rear side plate are provided with water-permeable holes.

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