WO2020077649A1

WO2020077649A1 - Cmp wafer cleaning apparatus

Info

Publication number: WO2020077649A1
Application number: PCT/CN2018/111386
Authority: WO
Inventors: 顾海洋; 张志军; 古枫; 王东辉
Original assignee: 杭州众硅电子科技有限公司
Priority date: 2018-10-15
Filing date: 2018-10-23
Publication date: 2020-04-23
Also published as: CN208938938U; CN109524330A

Abstract

Disclosed is a CMP wafer cleaning apparatus, comprising a sequentially arranged cleaning input unit, megasonic cleaning unit, first scrubbing unit, second scrubbing unit, and drying unit. A transfer manipulator and a flipping manipulator are located above the cleaning apparatus. The transfer manipulator comprises a horizontal movement shaft, a vertical movement shaft, and a wafer gripping device, and is capable of transferring a wafer between the units. The flipping manipulator fetches and flips the wafer in the gripping device. In addition, the apparatus further comprises a buffer unit located in front of the cleaning input unit and capable of temporarily storing a wafer. The apparatus further comprises a wafer polishing channel located between the cleaning input unit and the megasonic cleaning unit, and facilitates passage of a wafer through the cleaning apparatus when entering a polishing region prior to a CMP step. The buffer unit of the present invention is introduced so as to store a polished wafer in a safe manner when a failure of the CMP wafer cleaning apparatus occurs, thereby effectively resolving the issue of safely storing wafers at procedure transitions.

Description

CMP wafer cleaning equipment

Technical field

The invention belongs to the technical field of wafer grinding or polishing technology, and relates to a CMP wafer cleaning device applied to the field of wafer cleaning after CMP.

Background technique

With the rapid development of the semiconductor industry, the feature sizes of integrated circuits have continued to be miniaturized, and semiconductor chips have continuously developed towards small size, high circuit density, fast, and low power consumption. Integrated circuits have now entered ULSI sub-micron technology stage. With the gradual increase in the diameter of silicon wafers, the width of the reticle in the element gradually decreases, and the number of metal layers increases. Therefore, the high flatness of the surface of the semiconductor thin film has an important impact on the high performance, low cost, and high yield of the device. As a result, the requirements for the flatness of the surface of silicon wafers will become increasingly strict.

At present, as the only planarization technology chemical mechanical polishing technology that can obtain a global planarization effect, CMP (Chemical Mechanical Planarization) has developed into a chemical machinery that integrates online measurement, online end point detection, cleaning and other technologies. Polishing technology is the product of the development of integrated circuits towards miniaturization, multi-layering, thinning and planarization. At the same time, it is also a necessary process technology for the wafer to transition from 200mm to 300mm or even larger diameters, to improve productivity, reduce manufacturing costs, and globally flatten the substrate. After the wafer is subjected to CMP processing, processed removals and polishing liquid will remain on the wafer surface. In order to remove contaminants on the wafer surface in time, the CMP equipment needs to be used with cleaning equipment.

At present, the configuration of mainstream cleaning equipment includes a wafer vertical mode and a wafer horizontal mode, and the configuration of the cleaning unit of each equipment is different. The vertical cleaning unit can save equipment space, and the process consistency of megasonic cleaning and brushing is better. However, due to the influence of gravity during the drying process, the drying effect is not as good as the horizontal mode, and the horizontal cleaning unit is not conducive to pollutants in time. Remove the wafer surface. Therefore, according to the characteristics of the cleaning unit and the spin-drying unit, it is necessary to comprehensively consider the placement method of the wafer and how to implement the conversion of the wafer placement method. In addition, once the CMP wafer cleaning equipment fails, how to ensure the safe storage of the wafers that have completed the polishing process so that the cleanliness of the wafer surface is not affected is also a problem that needs to be considered and resolved.

Summary of the invention

The purpose of the present invention is to provide corresponding transmission methods for different configurations of various cleaning units, and how to ensure safe storage of polished wafers when the CMP wafer cleaning equipment fails during the existing wafer cleaning process Proposed a solution that can effectively solve the problem of safe storage of wafers between program conversions.

For this purpose, the technical solution proposed by the present invention is a CMP wafer cleaning equipment, including a cleaning input unit, a megasonic cleaning unit, a first brushing unit, a second brushing unit, a spin-drying unit, a transfer robot and a flip The manipulator is located above the cleaning equipment. The transfer manipulator includes a horizontal movement axis, a vertical movement axis, and a wafer gripping device, which can transfer wafers between the units, and the flipping robot grips the wafers in the gripping device. And flip. In addition, it also includes a buffer unit, which is located in front of the cleaning input unit and can temporarily store wafers.

The above equipment also includes a polishing wafer channel, which is located between the cleaning input unit and the megasonic cleaning unit, so that the wafer before the CMP step passes through the cleaning equipment when it enters the polishing area.

The wafer trays in the polished wafer channel and the cleaning input unit can be moved out simultaneously or separately to facilitate wafer loading operations.

A water spray device is provided in the buffer unit to prevent the wafer from drying without cleaning.

Preferably, 2-10 wafers can be temporarily stored in the buffer unit.

Preferably, the wafer is in a vertical direction during cleaning and brushing, and the wafer is in a horizontal direction during spin-drying.

When the process requirements of vertical spin-drying can meet the processing requirements, the wafers are in the vertical direction during the cleaning, brushing, and spin-drying processes.

The transition of the wafer from the horizontal to the vertical state is reversed by the transfer robot, or it can be realized by an independent flip robot.

The transfer robot includes a wafer grabbing device 1 and a wafer grabbing device 2 in the direction of cleaning the input unit to the spin-drying unit.

Under the condition that the cleaning capacity allows, the wafer grasping device one (603) near the spin-drying unit side can bring its own wafer turning function to save a turning manipulator.

Compared with the prior art, the present invention has the following beneficial technical effects:

1. The buffer unit introduced by the present invention can make the entire cleaning equipment more fault-tolerant. During the wafer cleaning process, when the CMP wafer cleaning equipment fails, it can achieve safe storage for the polished wafers and can also be effective. Solve the problem of safe storage of wafers between program conversions.

2. In order to use the space of the equipment more effectively in the present invention, the CMP wafer cleaning equipment may further include a polishing wafer channel, which is located between the cleaning input unit and the megasonic cleaning unit, so that the wafers before the CMP step enter the polishing area Cleaning equipment.

3. According to the different requirements of the wafer cleaning process, each cleaning unit may be in a vertical mode, or the spin-drying unit may be changed to a horizontal mode.

4. The transmission manipulator improves transmission efficiency by adopting a design that integrates two sets of gripping devices on a set of horizontal motion shafts, and avoids the potential collision hazards that may exist in the design of multiple sets of horizontal shafts.

BRIEF DESCRIPTION

1 is a structural diagram of a wafer cleaning device of the present invention;

Figure 2 is a perspective view of the wafer cleaning equipment;

3 is a three-dimensional effect diagram of the first embodiment;

4 is a stereoscopic effect diagram of the second embodiment;

Fig. 5 is a perspective view of the third embodiment.

detailed description

The present invention will be described in further detail below with reference to the drawings.

As shown in FIGS. 1 and 2, the wafer cleaning device for post-CMP cleaning provided by the present invention includes a buffer unit 8, a cleaning input unit 1, a polishing wafer channel 10, a megasonic cleaning unit 2, a brushing unit 3, and a brushing unit 4. Drying unit 5, transmission manipulator 6 and turning manipulator 7.

The buffer unit 8, the cleaning input unit 1, the polishing wafer channel 10, the megasonic cleaning unit 2, the scrubbing unit 3, the scrubbing unit 4 and the spin-drying unit 5 in the CMP wafer cleaning apparatus are arranged in a row in sequence. A group of transfer robots 6 is provided above the cleaning unit. The transfer manipulator 6 includes a horizontal movement axis 601, a vertical movement axis 602, a wafer gripping device one 603 and a wafer gripping device two 604.

In order to facilitate the wafer before CMP to pass through the cleaning unit when entering the polishing area, a polishing wafer channel 10 is provided in the cleaning unit. The polished wafer needs to be cleaned immediately. The wafer 9 to be cleaned is first put into the cleaning input unit 1. In order to prevent the wafer 9 from drying out in the waiting process, the cleaning input unit 9 is designed with a water spray device.

After the next cleaning unit Megasonic Cleaning Unit 2 finishes processing, the wafer picking device 2 604 of the transfer robot 6 picks up the wafer 9 in the cleaning input unit 1 along the vertical motion axis 602, and the wafer picking device 1 603 and The wafer picking device two 604 is transferred to the megasonic cleaning unit 2 along the horizontal movement axis 601, and the wafer picking device one 603 picks the wafer 9 in the megasonic cleaning unit 2 along the vertical movement axis 602. The device two 604 places the wafer 9 into the megasonic cleaning unit 2 along the vertical movement axis 602.

After the processing of the next cleaning unit brush unit 3 is completed, the wafer picking device one 603 and the wafer picking device two 604 are transferred to the top of the brush cleaning unit 3 along the horizontal movement axis 601, and the wafer picking device two 604 is along the vertical movement axis 602 picks up the wafer 9 in the scrubbing unit 3, and the wafer picking device 603 places the wafer 9 into the scrubbing unit 3 along the vertical movement axis 602.

After the processing of the next cleaning unit brush unit 4 is completed, the wafer picking device one 603 and the wafer picking device two 604 are transferred along the horizontal movement axis 601 to the brush cleaning unit 4, and the wafer picking device one 603 is along the vertical movement axis 602 picks up the wafer 9 in the scrubbing unit 4, and the wafer picking device two 604 places the wafer 9 into the scrubbing unit 4 along the vertical movement axis 602.

After the next cleaning unit spin-drying unit 5 finishes processing, the turning manipulator 7 grabs the wafer 9 in the grasping device 603 and turns it into the spin-drying unit 5. After the wafer 9 is processed in the spin-drying unit 5, the entire cleaning process is completed, and the wafer 9 is taken away by other equipment robots. In this way, the wafer 9 is cleaned.

When one or more of the cleaning units fails, the wafer 9 in the cleaning input unit 1 will be put into the buffer unit 8 by the gripping device 604. The buffer unit can be designed to accommodate 2 to 10 wafers 9 according to the capacity of the polishing equipment.

In addition, the CMP wafer cleaning equipment of the present invention generally also integrates a CMP polishing equipment and an equipment front end unit module (EFEM). Between the CMP wafer cleaning device and the CMP polishing device, a robot hand for transferring wafers is provided.

After the wafer is processed in the CMP polishing equipment, it is transferred by the robot to the cleaning input unit 1 of the present invention. With the participation of the transfer robot 6 and the flip robot 7, the wafer 9 passes through the megasonic cleaning unit 2 and the brush cleaning unit 3 in sequence The brushing unit 4 and the spin-drying unit 5 complete the entire cleaning process, and the robot in the EFEM finally removes the wafer 9 in the spin-drying unit 5.

The integrated CMP polishing device can simultaneously polish more than two wafers with different amounts. In order to prevent the CMP wafer cleaning device of the present invention from malfunctioning, the polished wafers cannot be safely stored. In the CMP wafer of the present invention A buffer unit 8 is designed in the cleaning equipment. According to the different processing capacity of the integrated CMP polishing equipment, the buffer unit 8 can temporarily store 2 to 10 wafers, and a water spray device is designed in the buffer unit 8 to prevent the wafers from drying without cleaning.

As an embodiment, as shown in FIG. 3, the cleaning input unit 1 and the polishing wafer channel 10 may be designed to be movable. When there is a wafer in the CMP polishing equipment that needs to be cleaned, the wafer carrier 11 in the cleaning input unit 1 is moved out of the tank to perform the wafer loading operation. After the wafer carrier 11 loads the wafer, it returns to the cleaning input unit 1 . Similarly, the wafer to be polished is placed on the wafer carrier 12 in the polishing wafer channel 10 from the EFEM unit, and the wafer carrier 12 can be moved out a corresponding distance to facilitate the removal of the wafer by the robot of the CMP polishing device. The movement of the cleaning wafer carrier 11 and the channel wafer carrier 12 may be simultaneous or may be designed to move independently of each other. This design can shorten the stroke of the manipulator in the CMP polishing equipment and reduce the area of the equipment.

As a second embodiment, as shown in FIG. 4, the wafer pick-up device 603 can be designed to have a wafer turning function. This can save a flip manipulator, but the transmission time will increase. This example can be used if the cleaning capacity allows.

As a third embodiment, as shown in FIG. 5, all cleaning units are designed in a vertical manner, so that the wafer 9 is prevented from turning over when entering the spin-drying unit 5. The wafer transmission unit has a simple mechanical structure and high transmission efficiency. This embodiment can be used when the process requirements of vertical spin-drying can meet the processing requirements.

The above description of specific embodiments is not intended to limit the present invention, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

A CMP wafer cleaning equipment includes a cleaning input unit (1), a megasonic cleaning unit (2), a first scrubbing unit (3), a second scrubbing unit (4), and a spin-drying unit (5) arranged in sequence, The transfer robot (6) and the flip robot (7) are located above the cleaning equipment. The transfer robot (6) includes a horizontal movement axis (601), a vertical movement axis (602), and a wafer gripping device, which can place the wafer in the Transfer between units, and the flip robot (7) grabs and flips the wafers in the wafer gripping device, characterized in that it further includes a buffer unit (8), which is located in the cleaning input unit In front of (1), wafers can be temporarily stored.
The CMP wafer cleaning device according to claim 1, characterized by comprising a polishing wafer channel (10), located between the cleaning input unit (1) and the megasonic cleaning unit (2), to facilitate Chemical mechanically polished wafers pass through the cleaning equipment when entering the polishing area.
The CMP wafer cleaning device according to claim 2, characterized in that both the polishing wafer channel (10) and the wafer carrier in the cleaning input unit (1) can be moved out simultaneously or separately to facilitate wafer loading operations.
The CMP wafer cleaning device according to claim 1, characterized in that a water spray device is provided in the buffer unit (8) to prevent the wafer from drying without cleaning.
The CMP wafer cleaning device according to claim 1, characterized in that several wafers can be temporarily stored in the buffer unit (8).
The CMP wafer cleaning device according to claim 1, wherein the wafer is in a vertical direction during cleaning and brushing, and the wafer is in a horizontal direction during spin-drying.
The CMP wafer cleaning device according to claim 1, wherein the wafers are in a vertical direction during cleaning, brushing, and spin-drying.
The CMP wafer cleaning apparatus according to claim 1, wherein the conversion of the wafer between the horizontal and vertical states is achieved by a transfer robot or an independent flip robot.
The CMP wafer cleaning apparatus according to claim 1, wherein the transfer robot includes a wafer picking device one (603) and a wafer picking device two (604).
The CMP wafer cleaning device according to claim 9, characterized in that a wafer grasping device (603) near the spin-drying unit side has a wafer turning function to save the turning manipulator.