KR100721756B1 - Apparatus for controlling temperature of polishing pad of chemical mechanical polishing equipment for wafer - Google Patents

Abstract

The present invention relates to a polishing pad temperature control apparatus for a wafer surface polishing equipment, the apparatus comprising: at least one spray nozzle disposed above the polishing pad and spraying a cooling material on the polishing pad; Cooling material supply pipe for supplying a cooling material to the injection nozzle; An internal rotating housing in communication with the cooling material supply pipe, the inner rotating housing rotating together with the carrier with the wafer held therein; An outer fixed housing formed in a shape surrounding the inner rotary housing, having an inlet through which cooling material is introduced, and a cooling material flow space communicating therewith with the cooling material supply pipe; A bearing installed between the inner rotary housing and the outer fixed housing; And a sealing member installed between the inner rotating housing and the outer fixed housing, so that the uniformity of polishing can be improved by uniform temperature control of the polishing pad, and the adhesion between the polishing pad and the platen is firm. It is possible to prevent the removal of the polishing pad by preventing the chemical reaction of the slurry to improve the polishing rate of the film layer, and to smoothly supply the cooling material from the upper side of the polishing pad to maintain a fast and efficient cooling performance. .

Polishing pad, spray nozzle, cooling material, housing, wafer

Description

Temperature control device for polishing pad of wafer surface polishing equipment {Apparatus for controlling temperature of polishing pad of chemical mechanical polishing equipment for wafer}

1 is a perspective view showing a conventional wafer surface polishing equipment.

Figure 2 is a perspective view showing a polishing pad temperature control device of the wafer surface polishing apparatus according to an embodiment of the present invention.

3 is a bottom view illustrating the polishing pad temperature control device of FIG. 2.

4 is a cross-sectional view taken along line IV-IV of FIG. 3.

5 is a partial cutaway cross-sectional view showing the polishing pad temperature control device of FIG.

Figure 6 is a conceptual diagram showing a polishing pad temperature control apparatus of the wafer surface polishing apparatus according to another embodiment of the present invention.

7 is a temperature distribution diagram of a polishing pad showing a temperature distribution according to a conventional polishing pad diameter position.

8 is a temperature distribution diagram of the polishing pad showing the temperature distribution according to the polishing pad diameter position when the polishing pad temperature control device of the wafer surface polishing apparatus of the present invention is applied.

<Description of Major Symbols in Drawing>

1: wafer 2: polishing pad

3: platen 4: wafer rotator

5: carrier 6: spindle

7: Conditioner 100: wafer surface polishing equipment

10, 30: polishing pad temperature controller 11: spray nozzle

12: cooling material 13: cooling material supply pipe

14: internal rotating housing 15: external fixed housing

16: bearing 17: sealing member

20: temperature measurement module 21: sensor knob

22: temperature sensor 23: wireless transmitter

24: contact terminal 31: wireless receiver

32: control unit 33: cooling material supply line

34: cooling material supply valve 35: injection nozzle valve

A: cooling material flow space

The present invention relates to a polishing pad temperature control apparatus of a wafer surface polishing equipment, and more particularly, by lowering the temperature of the polishing pad and improving the temperature uniformity by spraying a cooling material controlled according to the temperature of the polishing pad above the polishing pad. The present invention relates to a polishing pad temperature control device for a wafer surface polishing equipment.

In general, the semiconductor wafer process includes a plurality of processes such as ion implantation process, film deposition process, diffusion process, photographic process, surface polishing process, and cleaning process to form semiconductor elements in multiple layers on the surface of a wafer mainly made of silicon. Is done.

Among these processes, the wafer surface polishing equipment which performs the surface polishing process is generally a chemical-mechanical process that performs the fixing and planarization by removing the step between many wiring layers on the wafer surface through mechanical polishing and chemical reaction by the polishing liquid. CMP (Chemical Mechanical Polishing) equipment is widely used.

As shown in FIG. 1, the wafer surface polishing apparatus 100 is installed above the platen 3 to which the polishing pad 2 is attached and the polishing pad 2 to contact the polishing pad 2. And a wafer rotating device 4 for rotating and / or rotating the wafer 1, wherein the wafer rotating device 4 includes a carrier 5 for holding and rotating the wafer 1; And a spindle (6) for revolving the carrier (5), and a conditioner (7) for removing foreign matters and the like of the polishing pad.

Accordingly, as shown in FIG. 1, the conventional wafer surface polishing apparatus 100 is in contact with the polishing pad 2 supported by the platen 3, and the wafer 1 is in contact with the wafer ( 1) can rotate the surface of the wafer 1 in contact with the polishing pad 2 while rotating by the carrier 5 and processing by the spindle 6.

However, such a conventional wafer surface polishing apparatus 100, as shown in Figure 7, although the process of the wafer 1 and the wafer 1 during polishing, despite the temperature of the wafer 1 must be managed to 80 degrees Celsius or less in the process The frictional heat between the polishing pads 2 causes the temperature of the wafer 1 to rise above 100 degrees Celsius, particularly in the vicinity of the center of the polishing pads 2, thereby adversely affecting the polishing of the wafer film.

In addition, since the temperature distribution on the surface of the wafer 1 is unevenly polished as a result of uneven temperature rise of the polishing pad 2, the uniformity of polishing is greatly reduced, and the polishing pad is caused by the temperature rise of the polishing pad 2. The adhesive adhering the (2) and the platen 3 deteriorates and the adhesiveness decreases, resulting in a phenomenon that the polishing pad 2 is separated from the platen 3 during polishing.

In addition, the rapid temperature rise due to frictional heat during polishing of the wafer 1 causes chemical reactions with foreign substances such as slurry remaining after polishing, resulting in a change in components and a reduction in film removal rate (Removal-Rate).

On the other hand, even when a cooling device is installed on the platen 3 to cool the polishing pad 2, since the polishing pad 2 uses an insulator having a very low heat transfer rate, even if it is installed, the cooling effect is very low and the cooling time is low. There was such a problem as it takes a lot.

The present invention has been made to solve the above problems, the object of which is to manage the temperature of the wafer below 80 degrees Celsius can prevent adverse effects on the polishing of the wafer film layer due to frictional heat, Uniform temperature control can greatly improve the uniformity of polishing, and maintain the firm adhesion between the polishing pad and the platen to prevent the polishing pad from falling off and prevent the chemical reaction of the slurry to improve the film rate (Removal-Rate) The present invention provides a polishing pad temperature control device for a wafer surface polishing apparatus that can improve and maintain a quick and efficient cooling performance by smoothly supplying a cooling material from above the polishing pad.

The polishing pad temperature adjusting device of the wafer surface polishing apparatus of the present invention for achieving the above object, in the configuration of the polishing pad temperature control device of the wafer surface polishing equipment to adjust the temperature of the polishing pad, installed above the polishing pad At least one spray nozzle for spraying a cooling material on the polishing pad; Cooling material supply pipe for supplying a cooling material to the injection nozzle; An internal rotating housing in communication with the cooling material supply pipe, the inner rotating housing rotating together with the carrier with the wafer held therein; An outer fixed housing formed in a shape surrounding the inner rotary housing, having an inlet through which cooling material is introduced, and a cooling material flow space communicating therewith with the cooling material supply pipe; A bearing installed between the inner rotary housing and the outer fixed housing; And a sealing member installed between the inner rotary housing and the outer fixed housing.

In addition, according to the present invention, the cooling material is preferably a low-temperature clean dry air (CDA).

In addition, according to the present invention, it is preferable that the injection nozzle, the cooling material supply pipe, and the internal rotating housing are installed on a spindle for rotating a conditioner for holding the wafer and the conditioner for holding the wafer.

In addition, according to the present invention, it is possible to install a detachable temperature measuring module at the tip of the injection nozzle.

In addition, according to the present invention, the temperature measuring module includes a sensor node in contact with the polishing pad and made of a material having excellent heat transfer rate; A temperature sensor for measuring a temperature of heat transferred through the sensor node; A wireless transmitter which receives a temperature signal from the temperature sensor and converts the signal into a wireless form; And a contact terminal in contact with a probe pin connected to an external measuring device.

Meanwhile, according to the present invention, a real-time wired / wireless temperature signal is wirelessly applied from the temperature measuring module, and a cooling material supply valve installed in a cooling material supply line connected to a cooling material inlet of the external fixed housing in comparison with a reference value already input. The controller may further include a control signal for applying a control signal to the injection nozzle valve installed in the injection nozzle.

Hereinafter, a polishing pad temperature control apparatus for a wafer surface polishing apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, as shown in Figures 2 to 5, the polishing pad temperature control device 10 of the wafer surface polishing equipment according to an embodiment of the present invention, as to control the temperature of the polishing pad 2, The injection nozzle 11, the cooling material supply pipe 13, the inner rotary housing 14, the outer fixed housing 15, the bearing 16 and the sealing member 17 are constituted.

Here, as shown in FIG. 3, the spray nozzle 11 is installed above the polishing pad 2, and the polishing nozzle 12 may spray the cooling material 12 onto the polishing pad 2. A plurality of radiation is installed side by side in the outer direction from the center of the pad (2).

In addition, the cooling material supply pipe 13 is to supply the cooling material to the injection nozzle 11, so that the plurality of injection nozzles 11 are connected to each other.

4 and 5, the inner rotary housing 14 is in communication with the cooling material supply pipe 13 and rotates together with the carrier 5 in which the wafer 1 is held. The outer fixed housing 15 is formed in a shape surrounding the inner rotary housing 14, an inlet 18 through which cooling material is introduced is formed at one side thereof, and communicates with the cooling material supply pipe 13 therein. Cooling material flow space (A) is to be formed.

In particular, a bearing 16 is installed between the inner rotary housing 14 and the outer fixed housing 15 to enable rotation of the inner rotary housing 14 with respect to the outer fixed housing 15. A sealing member 17 is installed between the inner rotary housing 14 and the outer fixed housing 15 to prevent cooling material from leaking between the rotary housing 14 and the outer fixed housing 15.

Here, the cooling material 12 is preferably a low-temperature clean dry air (CDA) safe for processing the wafer 1 even if leaked to the outside, and a separate cooling air conditioner (not shown) may be installed to cool the CDA. Can be.

In addition, the injection nozzle 11, the cooling material supply pipe 13, and the internal rotating housing 14 may be provided with a conditioner 7 which maintains a state of the carrier 5 and the polishing pad 2 holding the wafer 1. It is installed on the spindle (6) to rotate the rotating pad with the wafer (1) above the polishing pad (2) to directly spray the cooling material 12 over the polishing surface of the polishing pad (2).

Here, as shown in FIG. 5, a detachable temperature measuring module 20 may be installed at the front end of the injection nozzle 11.

That is, the temperature measuring module 20 is in contact with the polishing pad 2 and measures the temperature of the heat transferred through the sensor node 21 and the sensor node 21 made of a material having excellent heat transfer rate. A probe pin (not shown) connected to a temperature sensor 22, a wireless transmitter 23 for receiving a temperature signal from the temperature sensor 22, converting it into a wireless form, and transmitting it to a wireless transmitter 23 and an external measuring device (not shown). It may be made including a contact terminal 24 in contact with.

Therefore, the operator can facilitate the replacement of the sensor node 21 or the replacement of the module by the temperature measuring module 20 detachably attached to the distal end of the injection nozzle 11, and often the external measuring equipment By using this, the normal operating state of the temperature sensor 22 can be checked.

On the other hand, the polishing pad temperature control apparatus 30 of the wafer surface polishing apparatus according to another embodiment of the present invention, the wireless receiving unit 31 that is wirelessly applied to the real-time wireless temperature signal from the temperature measuring module 20 and this The integrated control signal is applied to the cooling material supply valve 34 installed in the cooling material supply line 33 connected to the cooling material inlet 18 of the external fixed housing 15 compared to the reference value already input or the injection nozzle. It is possible to further include a control unit 32 for applying an individual control signal to the injection nozzle valve 35 provided in (11).

Here, although not shown, the wireless temperature signal may be transmitted by wire using a contact pin or the like.

Therefore, referring to the operation of the polishing pad temperature control device of the wafer surface polishing apparatus of the present invention, the cooling material 12 is a cooling material flow space (A) through the inlet 18 of the external fixed housing 15 Flows into the injection nozzle 11 through the cooling material supply pipe 13 of the inner rotary housing 14, and is sprayed at a high pressure on the polishing surface of the polishing pad 2.

At this time, the injection nozzle 11 is rotated together with the spindle 6, which can immediately cool the frictional heat of the polishing pad 2 while rotating with the revolution of the carrier 5 holding the wafer 1. will be.

In addition, when the sensor node 21 of the temperature measuring module 20 is in contact with the polishing pad 2 and the heat of the polishing pad 2 is transferred to the temperature sensor 22, the wireless transmitter 23 The temperature sensor 22 converts a temperature signal into a wireless form and transmits the temperature signal to the wireless receiver 31, and compares the control unit 32 with the reference value already input by the wireless receiver 31 to the external fixed housing. The control signal is applied to the cooling material supply valve 34 installed in the cooling material supply line 33 connected to the cooling material inlet 18 of the (15), or the injection nozzle valve 35 installed in the injection nozzle (11). By applying an individual control signal to the polishing pad 2 in real time or it is possible to adjust the individual temperature.

Here, the type of control signal applied to the cooling material supply valve 34 or the injection nozzle valve 35 may be wired or wireless.

Therefore, as shown in FIG. 8, even if the temperature distribution of the polishing pad 2 showing the temperature distribution according to the diameter position of the polishing pad 2 is uniform and flat, even in the center portion of the polishing pad 2, the temperature is in degrees Celsius. By keeping it below 80 degrees, the polishing of the optimum state becomes possible.

The present invention is not limited to the above-described embodiments, and of course, modifications may be made by those skilled in the art without departing from the spirit of the present invention.

For example, although the contact temperature sensor is illustrated in the embodiment of the present invention, the description of the design, form and type of the main components of the present invention may be applied to various types of contact and non-contact temperature sensors. Modifications and changes can be easily made by those skilled in the art without departing from the technical spirit.

Therefore, the scope of the claims in the present invention will not be defined within the scope of the detailed description, but will be defined by the following claims and the technical spirit thereof.

As described above, according to the polishing pad temperature control device of the wafer surface polishing apparatus of the present invention, it is possible to prevent adverse effects on the polishing of the wafer film layer due to frictional heat, and greatly improve the uniformity of polishing by uniform temperature control of the polishing pad. It maintains firm adhesion between the polishing pad and the platen to prevent separation of the polishing pad and prevent chemical reaction of the slurry to improve the film rate (Removal-Rate) and smooth the cooling material from above the polishing pad. It is to have the effect of maintaining a quick and efficient cooling performance by supplying the power.

Claims (6)

In constructing a polishing pad temperature control device of the wafer surface polishing equipment for controlling the temperature of the polishing pad, At least one spray nozzle disposed above the polishing pad and spraying a cooling material on the polishing pad; Cooling material supply pipe for supplying a cooling material to the injection nozzle; An internal rotating housing in communication with the cooling material supply pipe, the inner rotating housing rotating together with the carrier with the wafer held therein; An outer fixed housing formed in a shape surrounding the inner rotary housing, having an inlet through which cooling material is introduced, and a cooling material flow space communicating therewith with the cooling material supply pipe; A bearing installed between the inner rotary housing and the outer fixed housing; And A sealing member installed between the inner rotary housing and the outer fixed housing; Polishing pad temperature control apparatus of the wafer surface polishing equipment comprising a. The method of claim 1, The cooling material is a low temperature CDA (Clean Dry Air) polishing pad temperature control apparatus of the wafer surface polishing equipment, characterized in that. The method of claim 1, And the spray nozzle, the cooling material supply pipe, and the inner rotary housing are installed on a spindle for rotating a conditioner for maintaining a state of a carrier and a polishing pad for holding a wafer. The method of claim 1, A polishing pad temperature control apparatus for a wafer surface polishing apparatus, characterized in that a temperature measuring module is installed at a distal end of the spray nozzle. The method of claim 4, wherein The temperature measuring module, A sensor node in contact with the polishing pad; A temperature sensor for measuring a temperature of heat transferred through the sensor node; A wireless transmitter which receives a temperature signal from the temperature sensor and converts the signal into a wireless form; And A contact terminal in contact with a probe pin connected to an external measuring device; Polishing pad temperature control apparatus of the wafer surface polishing equipment comprising a. The method of claim 4, wherein The real-time wired and wireless temperature signal is wirelessly applied from the temperature measuring module, and a control signal is applied to a cooling material supply valve installed in a cooling material supply line connected to a cooling material inlet of the external fixed housing in comparison with a reference value already input. And a control unit for applying a control signal to an injection nozzle valve installed in the injection nozzle.

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