Chemical mechanical polishing equipment with polishing fluid heating device

Abstract

The utility model provides chemical mechanical grinding equipment with a grinding fluid heating device, which comprises a grinding table, a grinding pad, a grinding head and a grinding fluid supply pipe arranged in a grinding fluid supply arm, one end of the grinding fluid supply pipe is a fluid outlet, a heating pipe is arranged at the tail end of the fluid outlet, and the grinding fluid heating device is arranged on the grinding table. The heating pipe is located above the grinding pad and used for heating grinding liquid and conveying the grinding liquid to the grinding pad. According to the CMP device, the rapid heating device is additionally arranged at the tail end of the liquid outlet, and the CMP device is simple in structure, convenient to transform, high in heating efficiency and capable of recovering positive film production at any time.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor manufacturing, and particularly to a chemical mechanical polishing equipment with a polishing liquid heating device. Background Art

[0002] Chemical mechanical polishing (CMP) is the most commonly used method for wafer surface planarization. In the chemical mechanical polishing process, after the machine tool is idle, the temperature of the polishing pad will drop. For the first few wafers of the subsequent lot, due to insufficient and unstable polishing temperature, that is, the so-called slot effect, the inline performance will be unstable. To eliminate the slot effect in the chemical mechanical polishing process, usually several dummy wafers need to be run first after the machine tool is idle to raise the polishing temperature, and then the products are run. This inevitably causes waste of polishing liquid and production capacity.

[0003] Therefore, someone proposed to install a polishing liquid heating system in the existing chemical mechanical polishing device. Usually, a heating component is wrapped or wound outside the polishing liquid supply pipe (Slurry Arm) to heat the polishing liquid in the polishing liquid supply pipe, so as to increase the initial polishing temperature and ensure the polishing efficiency.

[0004] However, the above solutions still have some problems. First, the polishing liquid supply pipe in the chemical mechanical polishing device is usually made of corrosion-resistant materials. Common material selections include: polytetrafluoroethylene (PTFE), polyethylene (PE), polyurethane (PU), etc. These materials have poor thermal conductivity, resulting in low heating efficiency for the polishing liquid. Second, it is rather cumbersome to install a heating component outside the polishing liquid supply pipe and it is not easy to transform. Third, the polishing liquid supply pipe is relatively long. When the dummy wafers are finished and normal processing is to be resumed, the polished liquid that has been heated and remains in the pipeline cannot be quickly cooled to the corresponding temperature. It will cause certain adverse consequences due to the temperature difference at the initial stage of polishing the product wafers. Sometimes, the high-temperature polished liquid remaining in the polishing liquid pipeline needs to be discharged before processing the product wafers, which will further cause a large amount of polishing liquid waste. Summary of the Utility Model

[0005] In order to solve all or part of the above-mentioned problems in the prior art, the utility model provides a chemical mechanical polishing equipment with a polishing liquid heating device, so as to provide a chemical mechanical polishing device with a simple structure, convenient transformation, high heating efficiency and can resume normal wafer production at any time.

[0006] To achieve the above object, the utility model provides a chemical mechanical polishing equipment with a polishing liquid heating device, which includes a polishing table, a polishing pad, a polishing head, and a polishing liquid supply pipe arranged in a polishing liquid supply arm. One end of the polishing liquid supply pipe is a liquid outlet, and a heating pipe is arranged at the end of the liquid outlet. The heating pipe is located above the polishing pad and is used to heat the polishing liquid and transport it to the polishing pad. Installing the heating component at the end of the liquid outlet has a simple structure, is convenient for transformation, the heating pipe heats quickly, has high heating efficiency, and is convenient to stop heating at any time to prevent adverse effects on the production of positive films caused by high-temperature polishing liquid.

[0007] The heating pipe has a double-layer structure inside and outside. The inner layer of the heating pipe is a delivery pipe, which is a hollow tubular structure, and the outer layer of the heating pipe is a heating layer. The inner pipeline is used for transporting the polishing liquid, and the outer layer is used to provide a heat source to heat the polishing liquid.

[0008] The delivery pipe is a corrosion-resistant metal pipe. The polishing liquid has a certain corrosiveness, and the corrosion resistance can ensure the service life of the delivery pipe, while the metal material can improve the heat conduction efficiency and achieve rapid heating.

[0009] The delivery pipe is a copper pipe. Copper has both good corrosion resistance and a high thermal conductivity coefficient, and can achieve rapid heating of the polishing liquid.

[0010] The heating layer is a tubular structure tightly sleeved outside the delivery pipe, and a resistance wire for heating is arranged inside the tubular structure.

[0011] The heating layer is a resistance wire wound outside the delivery pipe.

[0012] The heating pipe is embedded at the end of the liquid outlet for connection. The connection is very convenient and is convenient for transformation, disassembly, and loading.

[0013] The delivery pipe of the heating pipe is embedded at the end of the liquid outlet, and the heating layer does not contact the liquid outlet. Not directly contacting can prevent possible potential damage to the liquid outlet during heating.

[0014] The delivery pipe of the heating pipe is sleeved at the end of the liquid outlet for connection. The connection is very convenient and is convenient for transformation, disassembly, and loading.

[0015] A temperature control device is also provided. The temperature control device includes a temperature sensor and a controller. The temperature sensor is arranged near the outlet of the heating pipe, and the controller is respectively connected to the temperature sensor and the heating layer to control the temperature of the polishing liquid. The temperature control device can achieve precise control of the temperature of the polishing liquid to adapt to different products.

[0016] Compared with the prior art, the main beneficial effects of the present utility model are as follows: The heating component is installed at the end of the liquid outlet. Compared with the prior art, the structure is simple and the transformation is convenient; a metal material is used as the delivery pipe, and in cooperation with resistance wire heating, rapid heating can be achieved, and the heating efficiency is high; when the processing of the accompanying wafer is completed, heating can be stopped at any time, and there will be no residual high-temperature abrasive slurry in the abrasive slurry supply pipe as in the prior art, preventing the adverse effects of high-temperature abrasive slurry on the production of the positive wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the specific embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following-described drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 Schematic diagram of a chemical mechanical polishing apparatus in the prior art provided by the present utility model.

[0019] Figure 2 Schematic diagram of a chemical mechanical polishing apparatus with an abrasive slurry heating device provided by the present utility model.

[0020] Figure 3 Schematic diagram of a heating pipe structure provided by the present utility model.

[0021] Figure 4 Test results of the prior art and the improved chemical mechanical polishing apparatus provided by the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] Regarding the foregoing and other technical contents, features and effects of the present utility model, they will be clearly presented in the following detailed description of a preferred embodiment in conjunction with the reference drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only with reference to the directions of the attached drawings. Therefore, the directional terms used are for illustration and not for limiting the present utility model.

[0023] As Figure 1Shown is a chemical mechanical polishing apparatus in the prior art, including a polishing table 300, a polishing pad 400, a polishing head 500, and a polishing liquid supply arm (not shown in the figure). Among them, the polishing pad 400 is attached to the polishing table 300, and the polishing head 500 is located above the polishing pad 400. A polishing liquid supply pipe 100 is provided inside the polishing liquid supply arm. One end of the polishing liquid supply pipe 100 is connected to a polishing liquid supply system (not shown in the figure), and the other end of the polishing liquid supply pipe 100 is a liquid outlet 110, which is located above the polishing pad 400 and is used to supply the polishing liquid 200 to the polishing pad 400.

[0024] When performing chemical mechanical polishing, first attach the surface to be polished of the silicon wafer downward to the polishing head 500, then apply a downward pressure through the polishing head 500 to tightly press the surface to be polished of the silicon wafer against the polishing pad 400. Then, the polishing table 300 and the polishing pad 400 attached to its surface rotate around the central axis driven by a motor, and the polishing head 500 also rotates around its central axis. While the polishing head 500 and the polishing table 300 are rotating, the polishing liquid 200 is transported to the polishing pad 400 through the polishing liquid supply pipe 100 and is evenly distributed on the polishing pad 400 under the action of the centrifugal force generated by the rotation of the polishing table 300.

[0025] In production practice experience, we found that when the chemical mechanical polishing machine tool stands by, the temperature of its polishing disk will drop, and the first few wafers of subsequent batches show unstable online performance due to insufficient and unstable polishing temperature. In order to eliminate the first wafer effect in the chemical mechanical polishing process, we usually run several dummy wafers first after the machine tool stands by to raise the polishing temperature and then run the products, but this inevitably causes waste of polishing liquid and production capacity. According to our research, during the chemical mechanical polishing process, the polishing temperature is an important factor affecting the polishing effect. Generally speaking, as the polishing temperature increases, the polishing rate increases accordingly. And the polishing temperature is related to both the polishing liquid temperature and the polishing disk temperature.

[0026] For this reason, someone proposed to heat the polishing disk, but the relevant transformation is relatively troublesome. There are also some patent documents mentioning improving the polishing temperature by heating the polishing liquid. They usually wrap or wind a heating component outside the polishing liquid supply pipe to heat the polishing liquid, but there are still problems such as low heating efficiency, cumbersome transformation, and difficulty in restoring at any time. For this reason, we propose a new technical solution.

[0027] As Figure 2 shown is a schematic diagram of a chemical mechanical polishing device with a polishing liquid heating device provided in this embodiment.

[0028] A chemical mechanical polishing equipment with a polishing liquid heating device, comprising a polishing table 300, a polishing pad 400, a polishing head 500 and a polishing liquid supply arm (not shown in the figure). Among them, the polishing pad 400 is attached to the polishing table 300, and the polishing head 500 is located on the polishing pad 400. A polishing liquid supply pipe 100 is arranged in the polishing liquid supply arm. One end of the polishing liquid supply pipe 100 is connected to the polishing liquid supply system, and the other end of the polishing liquid supply pipe 100 is an outlet 110. A heating pipe 120 is arranged at the end of the outlet 110. The heating pipe 120 is located above the polishing pad 400, and the heating pipe 120 can instantaneously heat the flowing polishing liquid 200 and transport it to the polishing pad 400.

[0029] As Figure 3 shown is a schematic diagram of a heating pipe provided in this embodiment.

[0030] In this embodiment, the provided heating pipe 120 has a double-layer structure inside and outside. Its inner layer pipe is a delivery pipe 121, and the outer layer is a heating layer 122. The delivery pipe 121 is a hollow tubular structure, and the material is a corrosion-resistant metal material (the corrosion-resistant metal can include elemental metal materials or alloy materials). In this embodiment, the delivery pipe 121 is a copper pipe because copper not only has good corrosion resistance but also has a high thermal conductivity coefficient, which can achieve rapid heating of the polishing liquid. In other embodiments, metals or alloy materials such as nickel, titanium, aluminum, and stainless steel can also be selected.

[0031] In this embodiment, the heating layer 122 is a tubular structure tightly sleeved outside the delivery pipe 121. A resistance wire for heating is arranged inside the tubular structure. Based on the principle of resistance heating, by applying current, the heating layer 122 can quickly generate a large amount of heat and conduct it to the inner delivery pipe 121 to further heat the polishing liquid 200 in the delivery pipe 121. Since the heating layer 122 can quickly generate a large amount of heat and the delivery pipe 121 has good thermal conductivity, the polishing liquid 200 can be heated in a very short time, that is, instant heating is achieved.

[0032] In other embodiments, in order to simplify the structure, the heating layer 122 can be simplified and does not necessarily require a tubular structure. That is, the above-mentioned heating pipe 120 still has a double-layer structure inside and outside, the inner layer pipe is still the delivery pipe 121, and the outside of the delivery pipe 121 is set as the heating layer 122, and the heating layer 122 can be formed by winding the resistance wire around the outer layer of the delivery pipe 121. By this method, instant heating of the polishing liquid 200 can also be achieved.

[0033] As described above, the heating pipe 120 is connected to the end of the liquid outlet 110. It should be noted that in a chemical mechanical polishing machine table, the above-mentioned liquid outlet 110 is actually a hollow pipe structure, and the internal space is used for the transportation of the polishing liquid 200. The material of the liquid outlet 110 is generally an elastic material such as plastic or Teflon (polytetrafluoroethylene). Therefore, the end of the liquid outlet 110 can be selected to be reamed, and then one end of the inner pipeline of the heating pipe 120, that is, the delivery pipe 121, is embedded into the end of the liquid outlet 110 for a certain distance to achieve the connection between the two. In this connection method, attention should be paid to controlling the size of the heating layer 122 to avoid direct contact between the heating layer 122 and the liquid outlet 110 and prevent damage to the liquid outlet 110 during heating; similarly, in other embodiments, the delivery pipe 121 can also be sleeved on the end of the liquid outlet 110 to achieve the connection. In this application, the connection method between the two is not strictly limited.

[0034] In this embodiment, in order to further control the temperature of the polishing liquid 200, a temperature control device is also provided. The temperature control device is composed of two parts: a temperature sensor and a controller (not shown in the figure). The temperature sensor is arranged near the outlet of the heating pipe 120 and can measure the temperature of the polishing liquid 200 flowing out of the heating pipe 120. The controller controls the heating layer 122 according to the temperature measured by the temperature sensor so that the temperature of the polishing liquid 200 is maintained at a certain set temperature.

[0035] The specific operation method of the temperature control device is as follows: The controller (the controller can specifically be an existing PID temperature controller) is respectively connected to the temperature sensor and the heating layer 122 (here it can be connected through wires or signal connection). A preset temperature can be set in the controller. The temperature sensor arranged near the outlet of the heating pipe 120 can collect the temperature of the flowing polishing liquid 200 in real time, transmit it to the controller and compare it with the preset temperature. When the measured temperature of the polishing liquid 200 is lower than the preset temperature, the controller controls the heating layer 122 to heat the polishing liquid 200 in the pipe. When the measured temperature of the polishing liquid 200 is higher than the preset temperature, the controller controls the heating layer 122 to stop heating. Repeat the above process until the collected temperature of the polishing liquid 200 is equal to the preset temperature.

[0036] By installing the heating pipe 120 at the end of the liquid outlet 110, rapid heating of the polishing liquid can be achieved. Through the temperature control device, precise control of the temperature of the polishing liquid can be achieved. The heating pipe 120 can be enabled only during dummy polishing and can be turned off during normal wafer processing, so that the output polishing liquid 200 is at the temperature during normal production, and there is no need to worry about the problem of residual high-temperature polishing liquid.

[0037] The chemical mechanical polishing device of the prior art and the improved chemical mechanical polishing device provided in this embodiment were tested, and the results are as Figure 4 shown. Figure 4 A is the result under the prior art. It is necessary to run 6 pieces of dummy wafers to ensure that the polishing temperature during the production of the main wafer can be reached. Figure 4 B is the result under the improved technology of this embodiment. Only 2 pieces of dummy wafers need to be run to ensure the stability of the polishing temperature during the subsequent production of the main wafer.

Claims

1. A chemical mechanical polishing device with a polishing liquid heating device, characterized in that: The invention comprises a grinding table (300), a grinding pad (400), a grinding head (500), and a grinding liquid supply pipe (100) arranged in a grinding liquid supply arm, wherein one end of the grinding liquid supply pipe (100) is a liquid outlet (110), a heating pipe (120) is arranged at the end of the liquid outlet (110), and the heating pipe (120) is located above the grinding pad (400). The heating pipe (120) is used to heat the grinding liquid (200) and transport it to the grinding pad (400).

2. The chemical mechanical polishing equipment with a polishing liquid heating device according to claim 1, characterized in that: The heating tube (120) is a double-layer structure with inner and outer layers. The inner layer of the heating tube (120) is a delivery tube (121), the delivery tube (121) is a hollow tubular structure, and the outer layer of the heating tube (120) is a heating layer (122).

3. The chemical mechanical polishing equipment with a polishing liquid heating device according to claim 2, characterized in that: The delivery pipe (121) is a corrosion-resistant metal pipe.

4. The chemical mechanical polishing equipment with a polishing liquid heating device according to claim 3, characterized in that: The delivery pipe (121) is a copper pipe.

5. The chemical mechanical polishing equipment with a polishing liquid heating device according to claim 2, characterized in that: The heating layer (122) is a tubular structure tightly sleeved on the outside of the delivery pipe (121), and a resistance wire for heating is arranged inside the tubular structure.

6. The chemical mechanical polishing equipment with a polishing liquid heating device according to claim 2, characterized in that: The heating layer (122) is a resistance wire wound around the outside of the conveying tube (121).

7. The chemical mechanical polishing equipment with a polishing liquid heating device according to claim 2, characterized in that: The heating tube (120) is embedded in the end of the liquid outlet (110) for connection.

8. The chemical mechanical polishing equipment with a polishing liquid heating device according to claim 7, characterized in that: The delivery pipe (121) of the heating pipe (120) is embedded in the end of the liquid outlet (110), and the heating layer (122) does not contact the liquid outlet (110).

9. The chemical mechanical polishing equipment with a polishing liquid heating device according to claim 2, characterized in that: The delivery pipe (121) of the heating pipe (120) is sleeved on the end of the liquid outlet (110) for connection.

10. The chemical mechanical polishing equipment with a polishing liquid heating device according to claim 2, characterized in that: A temperature control device is also provided, the temperature control device comprising a temperature sensor and a controller, the temperature sensor being provided near the outlet of the heating tube (120), and the controller being connected to the temperature sensor and the heating layer (122) respectively to control the temperature of the grinding liquid (200).

Images