WO2007004782A1

WO2007004782A1 - Pad conditioner and error detecting apparatus for the same

Info

Publication number: WO2007004782A1
Application number: PCT/KR2006/001058
Authority: WO
Inventors: Oh Su Kim
Original assignee: Oh Su Kim
Priority date: 2005-07-04
Filing date: 2006-03-23
Publication date: 2007-01-11

Abstract

Disclosed are a pad conditioner and an error detecting apparatus for the same. The pad conditioner according to the present invention includes a housing; a rotational body located on the inner side of the housing, in which a positioning portion is formed on the upper surface thereof; a rotational force transfer member engaged with the rotational body and connected to a drive unit for transferring a power; a rotational shaft engaged with the rotational force transfer member, to which a conditioning disc for optimizing a surface of a polishing pad for a semiconductor substrate is fixed; a nozzle for introducing air into a space portion formed in the interior of the rotational shaft; and a diaphragm cap for sealing the upper surface of the rotational body. A sealing member is provided between the rotational body and the rotational shaft. Further, the present invention provides an error detecting apparatus for detecting an error generated while conditioning the polishing pad of the pad conditioner.

Description

PAD CONDITIONER AND ERROR DETECTING APPARATUS

FOR THE SAME

[1] Technical Field

[2] The present invention relates to chemical mechanical polishing equipment, and more particularly to a pad conditioner which can maintain the surface roughness of a polishing pad constantly. Further, the present invention relates to an error detecting apparatus for a pad conditioner, and more particularly to an error detecting apparatus for a pad conditioner for applying an alarm signal to main equipment if an error is generated, by detecting up/down movement of a polishing head of the pad conditioner, a rotational speed, and a downward force when washing is performed in a clean cup.

[3] Background Art

[4] A semiconductor device manufacturing process includes a depositing process for forming thin film layers on a wafer and an etching process for forming a minute circuit pattern on the thin layers. The process is repeated until the circuit pattern required on the wafer is formed, and a great number of prominences are formed on the surface of the wafer. Recently, as semiconductor devices become highly integrated, the structures thereof have multi-layers and the number of the prominences on surfaces of wafers and the height differences between the prominences increase. However, since the unflatness of surfaces of wafers causes problems such as defocus and the like in photolithography processes, the surfaces of the wafers should be periodically polished to flatten them.

[5] There are various surface flattening technologies for flattening surfaces of wafers.

Among them, since chemical and mechanical polishing equipment can obtain an excellent flattening degree in flattening a wide area as well as a small area, it is widely used.

[6] The chemical mechanical polishing equipment polishes a surface of a wafer, on which tungsten or an oxide is coated, not only by using mechanical frictions but also by using an abrasive, and can make the surface of the wafer very minute. The mechanical method polishes the surface of the wafer by applying a pressure on the wafer and rotating the wafer with the polishing pad, which is a rotating polishing plate and thus by using frictions between a polishing pad and the surface of the wafer. On the other hand, the chemical method polishes the surface of the wafer by using a chemical abrasive of slurry which is supplied between the polishing pad and the wafer.

[7] General chemical mechanical polishing (hereinafter, referred to as CMP) equipment includes a polishing head absorbing a wafer by using vacuum and rotated by a motor, and a platen located at a lower portion of the polishing head, to which a polishing pad for polishing the wafer is attached. For more efficient polishing process, the surface roughness of the polishing pad should be maintained constantly. Namely, if the CMP equipment is continuously driven, the surface roughness of the polishing pad lowers and the polishing efficiency of the polishing pad decreases. Therefore, a pad conditioner is used to maintain the roughness of the polishing pad constantly.

[8] A conventional pad conditioner used in semiconductor manufacturing equipment includes a disc in which diamonds are uniformly disposed on the bottom surface thereof. The pad conditioner is rotated on its axis and is swung on a polishing pad at the same time. The interior of the pad conditioner is vacuumed, and the pad conditioner is moved up and down vertically by about 12 mm. This is because the pad conditioner is minutely moved up and down to maintain the horizontal state of a disc when the disc polishes a wafer.

[9] On the other hand, the conventional pad conditioner blocks the air discharged outside by using a thin rubber pad, in order to maintain the interior thereof in a vacuumed state. However, when the disc is rotated, the rubber pad is easily abraded. So, the conventional pad conditioner has a problem in that the rubber pad should be exchanged approximately once or twice a week. Therefore, the conventional pad conditioner requires a human power and a cost for maintaining and repairing it.

[10] Further, the conventional pad conditioner has no alarm system for informing an operator of generation of an error when up/down position errors generated while conditioning the polishing pad rotated on a platen, a break of a belt, and a change of a down force while moving down the conditioning head in a clean cup, or has no separate function for turning off main equipment and thus enabling an operator to recognize the generation of an error.

[11] Disclosure of the Invention

[12] Therefore, the present invention has been made in view of the above-mentioned problems, and it is the first object of the present invention to provide a pad conditioner in which a sealing member installed in the interior thereof, for maintaining a vacuumed state thereof, is constituted in a cylinder type.

[13] It is the second object of the present invention to minimize the error rate due to malfunction of equipment by detecting up/down position when a wafer is polished.

[14] It is the third object of the present invention to provide an error detecting apparatus for a pad conditioner, for detecting various errors which can be generated by a pad conditioner when a polishing pad performs conditioning and for transferring error signals corresponding to the errors to main equipment.

[15] It is the fourth object of the present invention to provide an error detecting apparatus for a pad conditioner, for visually and auditorily informing an operator of generation of an error in a pad conditioner.

[16] According to one aspect of the present invention, there is provided a pad conditioner comprising: a housing; a rotational body located on the inner side of the housing, in which a positioning portion is formed on the upper surface thereof; a rotational force transferring member engaged with the rotational body and connected to a drive unit for transferring a power; a rotational shaft engaged with the rotational force transferring member, to which a conditioning disc for optimizing a surface of a polishing pad for a semiconductor substrate is fixed; a nozzle for introducing air into a space portion formed in the interior of the rotational shaft; a diaphragm cap for sealing the upper surface of the rotational body; and a sealing member provided between the rotational body and the rotational shaft.

[17] The sealing member can comprise: a flat plate portion adhered along the inner side wall of the diaphragm cap; and a horizontal portion integrally formed with the flat plate portion and protruding downwardly. A groove is formed along the outer peripheral surface of the flat plate portion. An air blocking member can be provided in the groove.

[18] The present invention can further comprise: a plate surrounding a portion of the rotational shaft and engaged with the lower side of the housing; and a sensor installed on the inner side wall of the plate, for detecting up/down positions of the rotational shaft.

[19] A magnetic body can be installed at the rotational shaft adjacently to the sensor.

[20] According to other aspect of the present invention, there is provided an error detecting apparatus for detecting an error of a pad conditioner comprising a conditioning head for performing conditioning while making contact with a polishing pad used during a chemical mechanical polishing process, a rotational shaft for rotating the conditioning head, a support portion for supporting the rotational shaft, a driving motor for applying a rotational force to the rotational shaft, a pulley, and a belt, the error detecting apparatus comprising: a down-sensor unit for detecting whether the conditioning head is moved down toward the polishing head by more than a predetermined distance and for generating an error signal if the conditioning head is moved down toward the polishing head by more than the predetermined distance; an up-sensor unit for detecting whether the conditioning head is moved up toward the opposite side of the polishing head by more than a predetermined distance and for generating an error signal if the conditioning head is moved up toward the opposite side of the polishing head by more than the predetermined distance; a rotational speed detecting sensor unit for detecting the rotational speed of the pulley driving the rotational shaft for rotating the conditioning head and for generating an error signal if the rotational speed of the pulley is deviated from a predetermined rotational speed range; and a control unit for receiving the error signals from the down-sensor unit and the up-sensor unit and applying alarm signals corresponding to the error signals to main equipment, and for displaying the rotational speed through the detection signal applied from the rotational speed detecting sensor unit, and for applying an alarm signal to the main equipment if the detected rotational speed is rapidly lowered.

[21] The up-sensor unit can comprise: a first magnetic installed at the rotational shaft; and a first magnetic sensor installed at a lower portion of the support portion so as to detect the first magnetic.

[22] The down-sensor unit can comprise: a second magnetic installed on the inner side of the conditioning head; and a second magnetic sensor installed at a lower portion of the support portion so as to detect the second magnetic.

[23] The rotational speed detecting sensor unit can comprise: a flag installed at a position adjacent to the pulley; and a sensor for detecting whether there is the flag.

[24] The present invention can further comprise: a load cell installed at a clean cup, for detecting the pressure of the conditioning head moved down into the clean cup as the pad conditioner is moved to the clean cup to wash the conditioner pad, and the control unit can receive an analog pressure signal detected by the load cell, can convert the analog pressure signal to a digital pressure signal, can display the digital pressure signal, and can apply the digital pressure signal to the main equipment.

[25] The present invention can further comprise: a display panel for displaying signals applied from the down-sensor unit, the up-sensor unit, the rotational speed detecting sensor unit, and the load cell.

[26] The present invention can further comprise: an alarm means for alarming an operator on the basis of error signals applied from the down-sensor unit, the up-sensor unit, the rotational speed detecting sensor unit, and the load cell. In this case, it is preferable that the alarm means is a buzzer and/or an LED lamp.

[27] Brief Description of the Drawings

[28] The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

[29] FIG. 1 is a cross-sectional view for showing a pad conditioner according to the present invention;

[30] FIG. 2 is an exploded perspective view for showing a pad conditioner according to the present invention;

[31] FIG. 3 is a partially cutaway perspective view for showing a sealing member of a pad conditioner according to the present invention;

[32] FIG. 4 is a schematic block diagram for showing an error detecting apparatus for a pad conditioner according to the present invention; [33] FlG. 5 is a schematic perspective view for showing an error detecting apparatus for a pad conditioner according to the present invention; [34] FlG. 6 is a schematic view for describing a state in which sensors of an error detecting apparatus for a pad conditioner according to the present invention are installed at the pad conditioner; [35] FlG. 7 is a schematic view for describing a state in which a pad conditioner according to the present invention is moved down into a clean cup; [36] FlG. 8 is a flow chart for describing an error detecting process performed by a down-sensor unit of an error detecting apparatus for a pad conditioner according to the present invention; [37] FlG. 9 is a flow chart for describing an error detecting process performed by an up- sensor unit of an error detecting apparatus for a pad conditioner according to the present invention; [38] FlG. 10 is a flow chart for describing an error detecting process performed by a rotational speed detecting sensor unit of an error detecting apparatus for a pad conditioner according to the present invention; and [39] FlG. 11 is a flow chart for describing an error detecting process performed by a load cell of an error detecting apparatus for a pad conditioner according to the present invention.

[40] Best Mode for Carrying Out the Invention

[41] Hereinafter, the constitution and operation of a pad conditioner of a semiconductor substrate polishing device according to the present invention will be described with reference to the accompanying drawings. [42] FlG. 1 is a cross-sectional view for showing a pad conditioner according to the present invention, FlG. 2 is an exploded perspective view for showing a pad conditioner according to the present invention, and FlG. 3 is a partially cutaway perspective view for showing a sealing member of a pad conditioner according to the present invention. [43] As shown in FlGs. 1 to 3, the pad conditioner 100 according to the present invention includes a housing 10, a rotational body 20, a disc 30, a rotational shaft 40, a rotational force transferring member 50, a nozzle 60, a diaphragm cap 70, and a sealing member 80. [44] The housing 10 has a cylindrical outer surface so that the outer surface has a same radius from the central portion thereof. An upwardly opened receiving portion 11 is formed in the interior of the housing 10. A through-hole 12 is communicated with the lower side of the receiving portion 11 and extends to the lower end of the housing 10.

The housing 10 has the external shape of the pad conditioner. [45] The rotational body 20 is installed in the receiving portion 11. The central portion of the rotational body 20 is penetrated from the upper end thereof to the lower end thereof, like the central portion of the housing 10. A positioning portion 21 is formed on the upper surface of the rotational body 20. An insertion groove 22 is formed on the lower end surface of the rotational body 20 along the circumference of the rotational body 20. A bearing 23 is mounted into the insertion groove 22 so that the rotational body 20 can be rotated with respect to the housing 10. At least two sealing groove 21a and 21b are formed on the positioning portion 21 along the circumference of the positioning portion 21. The sealing groove 21a and 21b are adhered to the diaphragm cap 70 and the sealing member 80, which are described later, respectively. On the other ha nd, the rotational body 20 is connected to a drive unit (not shown) so that a rotational force can be transferred to the rotational body 20.

[46] Diamond particles are provided on the lower end surface of the disc 30. The disc

30 maintains the constant surface roughness of the polishing pad. The disc 30 is well known in the field of manufacturing a semiconductor and the detailed explanation thereof will be omitted.

[47] The rotational shaft 40 is connected to the central portion of the disc 30, and the lower end of the rotational shaft 30 is sealed. A space portion 41 is formed in the interior of the rotational shaft 30, and the rotational shaft 30 is opened to the upper end thereof. The space portion is connected to the rotational force transferring member 50, which is described later, by using a bush. A lower portion of the rotational body 20 is formed adjacently to the through-hole 12 of the housing 10. The rotational body 20 has a diameter from a central portion to an upper portion thereof, which is smaller than that of a lower portion thereof. Therefore, a chamber is formed between the rotational shaft 40 and the rotational body 20.

[48] The rotational force transferring member 50 is engaged with a pulley connected to a drive motor (not shown) by means of a V-belt. The rotational force transferring member 50 extends vertically to the space portion provided in the interior of the rotational shaft.

[49] The nozzle 60 is connected to an air injection unit (not shown). The tip end of the nozzle 60 is located in the space portion 41 formed in the rotational shaft 40. It is more preferable that the tip end of the nozzle 60 is adjacent to the lowest position of the space portion 41. Air is injected through the nozzle 60 from the air injection unit provided outside. The nozzle 60 maintains the horizontal state of the disc 30 so that the surface roughness of the polishing pad can be constant.

[50] The diaphragm cap 70 is located on the positioning portion 21 formed in the rotational body 20. The diaphragm cap 70 prevents the air introduced into the rotational shaft 40 and the rotational body 20 from being leaked outward so that a predetermined pressure is maintained in the rotational shaft 40. [51] The sealing member 80 is installed between the rotational shaft 40, and the rotational body 20 and the diaphragm cap 70. The sealing member 80 includes a flat plate portion 81 and a vertical portion 82. The side surface of the flat plate portion 81 is adhered along the inner side wall of the diaphragm cap 70. The lower surface of the flat plate portion 81 is adhered to the positioning portion formed in the rotational body 20. The vertical portion 82 is located between the rotational shaft 40 and the rotational body 20.

[52] The sealing member 80 has at least two grooves 81a and 82a. One 81a of the grooves is formed along the outer peripheral side surface of the flat plate portion 81, and the other 82a of the grooves is formed along the circumference of the lower end surface of the vertical portion 82. Air blocking members 83, which are O-rings, are installed in the grooves 81a and 82a so as to prevent the air introduced through the nozzle 60 and the space portion 41 from being discharged outside, thereby maintaining a predetermined pressure of the pad conditioner.

[53] A plate 90 is engaged with the lower side of the housing 10. The interior of the plate 90 is penetrated so that the rotational shaft 40 is located in the plate 90. The plate 90 is engaged with the housing 10, surrounding a portion of the housing 10. Further, a sensor 91 is installed on the inner side wall of the plate 90. The sensor 91 detects up/ down positions of the rotational shaft 40.

[54] A magnetic body 92 is installed at the rotational shaft 40 at a position adjacent to the sensor 91 in order to more accurately recognize the up/down positions of the rotational shaft 40.

[55] Hereinafter, the operation of the pad conditioner of the semiconductor substrate polishing device according to the present invention will be described in detail.

[56] A drive force is applied to the pad conditioner 100 of the substrate polishing device in order to polish a surface of a wafer according to semiconductor manufacturing processes. The drive force is operated by a drive motor (not shown) and transfers a rotational force to the rotational body 20 by using a V-belt. The rotational body 20 to which the rotational force is transferred is rotated in one direction in the interior of the housing 10. Then, the housing 10 is in a fixed state, and the rotational body 20 is rotated by itself with respect to the housing 10 due to a bearing. Further, the rotational shaft 40 connected to the rotational body 20 and the conditioning disc 30 are rotated together. Further, in the air injection unit, air is injected through the nozzle 60. The air introduced through the nozzle 60 is supplied into the space portion 41 formed in the interior of the rotational shaft 40.

[57] The air introduced into the space portion 41 is moved into the diaphragm cap 70, and the nozzle 60 introduces air continuously. Then, the grooves 81a and 82a, the sealing grooves 21a and 21b, and the air blocking member 83 installed in the insertion groove 22 prevents a minute amount of air from being discharged outside. Therefore, the sealing member 80 applies a pressure to the rotational shaft 40 by using a force toward the lower side thereof. In this state, the disc 30 polishes the upper surface of a wafer. Therefore, when a wafer is polished, the disc 30 is prevented from being moved minutely. Further, in the case of a malfunction of a device, the sensor 91 recognizes the movement of the magnetic body 92 and transfers a signal to a separate control unit (not shown) to stop the operation of the device.

[58] Hereinafter, the constitution of an error detecting apparatus for a pad conditioner according to the present invention will be described in detail with reference to FIGs. 4 to 7.

[59] FIGs. 4 and 5 are a schematic block diagram and a schematic perspective view for showing the error detecting apparatus for the pad conditioner according to the present invention, respectively. FIG. 6 is a schematic view for describing a state in which sensors of the error detecting apparatus for the pad conditioner according to the present invention are installed at the pad conditioner. FIG. 7 is a schematic view for describing a state in which the pad conditioner according to the present invention is moved down into a clean cup.

[60] As shown in FIG. 4, the error detecting apparatus 110 according to the present invention includes a down-sensor unit 120 for detecting whether the disc 30 of the pad conditioner 100 is moved down by more than a predetermined distance, an up-sensor unit 130 for detecting whether the disc 30 of the pad conditioner 100 is moved up by more than a predetermined distance, a rotational speed detecting sensor unit 140, and a load cell 150, on the input side thereof. The error detecting apparatus 110 includes a control unit 111 to which detection signals are applied from the sensor units. Further, the error detecting apparatus 110 includes a pressure switch 190 for controlling the pressure of the nozzle 50 for supplying the air of the pad conditioner 100 and for maintaining the pad conditioner 100 in a vacuumed state.

[61] As shown in FIGs. 5 and 6, the down-sensor unit 120 includes a first magnetic 123 installed at the rotational shaft 40 of the pad conditioner 100 and a down-sensor 121 for detecting the strength of the magnetic force of the first magnetic 123 moved down as the rotational shaft 40 and the disc 30 are moved down by the air injected through the nozzle 60 when the polishing pad 500 is conditioned.

[62] If the disc 30 is moved down by more than a predetermined distance toward the polishing pad (not shown) disposed on the lower side of the disc 30, the down-sensor unit 120 detects it and generates an error signal.

[63] As shown in FIGs. 5 and 6, the up-sensor unit 120 includes a second magnetic 133 installed on the inner side of the disc 30 of the pad conditioner 100 and an up-sensor 121 for detecting the strength of the magnetic force of the second magnetic 133 moved up as the rotational shaft 40 and the disc 30 are moved up by the vacuumed state of the nozzle 60 when the polishing pad 500 is conditioned.

[64] If the disc 30 is moved up by more than a predetermined distance toward the opposite side of the polishing pad (not shown) disposed on the lower side of the disc 30, the up-sensor unit 130 detects it and generates an error signal.

[65] Further, as shown in FIGs. 5 and 6, the error detecting apparatus according to the present invention includes the rotational speed detecting sensor unit 140 for detecting the rotational speed of the pulley 14 for driving the rotational shaft 40 by using a V- belt (not shown).

[66] The rotational speed detecting sensor unit 140 detects the rotational speed of the pulley 14 through a flag 141 disposed adjacently to the pulley 14. If the rotational speed of the pulley 14 is deviated from a predetermined rotational speed range, for example, in the case in which the rotational speed rapidly decreases as the belt breaks, the rotational speed detecting sensor unit 140 generates a rotational speed error signal.

[67] Further, the load cell 150 is installed in a clean cup 300 for washing the disc 30.

[68] If the disc 30 is moved down into the clean cup 300 by the air injected into the nozzle 60 and a pressure applied to the disc 30, the load cell 150 applies a pressure signal detected by the disc 30 to the control unit 111. Then, if the load cell 150 applies an analog signal to the control unit 111, the control unit 111 converts the analog signal to a digital signal.

[69] The error detecting apparatus 110 according to the present invention includes a display panel 160 for informing an operator of signals applied from the down-sensor unit 120, the up-sensor unit 130, the rotational speed detecting sensor unit 140, and the load cell 150, on the output side thereof. It is preferable that the display panel 160 is a touch screen.

[70] Further, the error detecting apparatus 110 includes an alarm means such as a buzzer

170 and an LED lamp 180, for alarming an operator on the basis of the error signals applied from the down-sensor unit 120, the up-sensor unit 130, the rotational speed detecting sensor unit 140, and the load cell 150. The reference numeral 400 represents a drive motor for rotating the pulley.

[71] Hereinafter, the error detecting processes of the pad conditioner according to the present invention will be described in detail with reference to FIGs. 8 to 11.

[72] FIG. 8 is a flow chart for describing an error detecting process performed by a down-sensor unit of an error detecting apparatus for a pad conditioner according to the present invention. FIG. 9 is a flow chart for describing an error detecting process performed by an up-sensor unit of an error detecting apparatus for a pad conditioner according to the present invention. FIG. 10 is a flow chart for describing an error detecting process performed by a rotational speed detecting sensor unit of an error detecting apparatus for a pad conditioner according to the present invention. FlG. 11 is a flow chart for describing an error detecting process performed by a load cell of an error detecting apparatus for a pad conditioner according to the present invention.

[73] First, as shown in FlG. 8, if the pressure switch (not shown) of main equipment 20

(refer to FlG. 4) is turned on, air is injected through the nozzle 60 of the pad conditioner 100. In this case, if air is not injected or the pressure is not set to a predetermined value, the pressure switch 190 (refer to FlG. 6) is checked.

[74] If the rotational shaft 40 is moved down by the pressure of the air injected through the nozzle 60 and the disc 30 is moved to a down position, the first magnetic 123 is also moved to the down position.

[75] Accordingly, the down-sensor 121 starts down-position sensing. Then, if the disc

30 is moved down below a predetermined down-position, the control unit 111 checks a value applied from the down-sensor 121 to determine an error, transfers an alarm signal to the main equipment 200, and enables the main equipment 200 to promptly perform an operation for coping with the error, for example, by turning the pad conditioner 100 off.

[76] On the other hand, the control unit 111 informs an operator of the error through the buzzer 170 and the LED lamp 180 so that the operator can promptly cope with the error.

[77] Further, as shown in FlG. 9, if the pressure switch (not shown) of the main equipment 200 is turned on, the air is discharged through the nozzle 60 of the pad conditioner 100 to form a vacuumed state. In this case, if the vacuumed state is not formed, the pressure switch 190 (refer to FlG. 6) is checked.

[78] If the rotational shaft 40 is moved up and the disc 30 is moved to an up position as the air introduced through the nozzle 60 is discharged, the second magnetic 133 is also moved to the up position.

[79] Accordingly, the up-sensor starts up-position sensing. Then, if the disc 30 is moved up above a predetermined up-position, the control unit 111 checks a value applied from the up-sensor 131 to determine an error, transfers an alarm signal to the main equipment 200, and enables the main equipment 200 to promptly perform an operation for coping with the error, for example, by turning the pad conditioner 100 off.

[80] On the other hand, as in the down-sensing process, the control unit 111 informs an operator of the error through the buzzer 170 and the LED lamp 180 so that the operator can promptly cope with the error.

[81] As shown in FlG. 10, in order to detect the rotational speed of the disc 30 of the pad conditioner 100, the rotational speed detecting sensor unit 130 is operated if the disc 30 is deviated from an initial position of the clean cup 300.

[82] In other words, the rotational speed detecting sensor unit 140 detects the rotational speed of the pulley 14 through the flag 141 disposed adjacently to the pulley 14. If the rotational speed of the pulley 14 is deviated from a predetermined rotational speed range, for example, in the case in which the rotational speed rapidly decreases as the belt (not shown) breaks, the control unit 111 determined the pulley 14 to be in an error state.

[83] Accordingly, the control unit 111 transfers an alarm signal to the main equipment and enables the main equipment 200 to promptly perform an operation for coping with the error, for example, by turning the pad conditioner 100 off. In this case, the control unit 111 informs an operator of the error through the buzzer 170 and the LED lamp 180 so that the operator can promptly cope with the error.

[84] Of course, the control unit 111 displays the rotational speed of the disc 30 on the display panel 160 connected to the output side of the error detecting apparatus, so that an operator can recognize the rotational speed in real time.

[85] Further, as shown in FIG. 11, in the error detecting process performed by the load cell 150, if the disc 30 is located at the initial position of the clean cup 300, the rotational speed detecting sensor unit 140 is turned off and an initializing sensor (not shown) of the clean cup 300 is turned on.

[86] Thereafter, if a pressure is applied to the nozzle 60, the disc 30 is moved down into the clean cup 300. Then, a pressure is applied to the load cell 150 mounted into the clean cup 300 and an analog pressure signal is applied to the control unit 111.

[87] Accordingly, the control unit 111 compares the pressure signal with a predetermined pressure range. Then, if the pressure signal is determined to be deviated from the pressure range, the control unit 111 transfers an alarm signal to the main equipment 200 and enables the main equipment 200 to promptly perform an operation for coping with the error, for example, by turning the pad conditioner 100 off.

[88] Of course, even in this case, the control unit 111 informs an operator of the error through the buzzer 170 and the LED lamp 180 so that the operator can promptly cope with the error, and displays a down force value applied to the load cell 150 through the display panel 160.

[89] According to the present invention, since various errors generated by the pad conditioner are detected in advance, an error time can be reduced, thereby improving the overall working efficiency.

[90] While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiment and the drawings, but, on the contrary, it is intended to cover various modifications and variations within the spirit and scope of the appended claims.

[91] Industrial Applicability [92] The effects of the pad conditioner of the semiconductor polishing device according to the present invention are as follows.

[93] First, air is introduced into the space portion formed in the interior of the rotational shaft through the nozzle, and the diaphragm cap maintains the interior of the pad conditioner in a vacuumed state. Therefore, when a wafer is polished, the disc is prevented from being moved minutely.

[94] Second, the sealing member is provided between the rotational shaft and the rotational body, and the air blocking member, which is an O-ring, is installed at the sealing member. Therefore, the continuously introduced air applies a pressure to the sealing member downward to prevent minute movements of the rotational shaft and the disc. Further, the air blocking member prevents a minute amount of air from being discharged outside, thereby maintaining the interior of the pad conditioner in a vacuumed state.

[95] Third, since the magnetic body is installed at the rotational shaft and the sensor is provided in the plate engaged with the housing, the rotational shaft is prevented from being deviated from a predetermined malfunction range when the rotational shaft is moved up and down. Therefore, a process line due to a malfunction of the pad conditioner can be automatically and promptly controlled while polishing a wafer.

Claims

[ 1 ] A pad conditioner comprising : a housing; a rotational body located on the inner side of the housing, in which a positioning portion is formed on the upper surface thereof; a rotational force transferring member engaged with the rotational body and connected to a drive unit for transferring a power; a rotational shaft engaged with the rotational force transferring member, to which a conditioning disc for optimizing a surface of a polishing pad for a semiconductor substrate is fixed; a nozzle for introducing air into a space portion formed in the interior of the rotational shaft; a diaphragm cap for sealing the upper surface of the rotational body; and a sealing member provided between the rotational body and the rotational shaft.

[2] A pad conditioner according to claim 1, wherein the sealing member comprises: a flat plate portion adhered along the inner side wall of the diaphragm cap; and a horizontal portion integrally formed with the flat plate portion and protruding downwardly, a groove is formed along the outer peripheral surface of the flat plate portion, and an air blocking member is provided in the groove.

[3] A pad conditioner according to claim 1, further comprising: a plate surrounding a portion of the rotational shaft and engaged with the lower side of the housing; and a sensor installed on the inner side wall of the plate, for detecting up/down positions of the rotational shaft.

[4] A pad conditioner according to claim 3, wherein a magnetic body is installed at the rotational shaft adjacently to the sensor.

[5] An error detecting apparatus for detecting an error of a pad conditioner comprising a conditioning head for performing conditioning while making contact with a polishing pad used during a chemical mechanical polishing process, a rotational shaft for rotating the conditioning head, a support portion for supporting the rotational shaft, a driving motor for applying a rotational force to the rotational shaft, a pulley, and a belt, the error detecting apparatus comprising: a down-sensor unit for detecting whether the conditioning head is moved down toward the polishing head by more than a predetermined distance and for generating an error signal if the conditioning head is moved down toward the polishing head by more than the predetermined distance; an up-sensor unit for detecting whether the conditioning head is moved up toward the opposite side of the polishing head by more than a predetermined distance and for generating an error signal if the conditioning head is moved up toward the opposite side of the polishing head by more than the predetermined distance; a rotational speed detecting sensor unit for detecting the rotational speed of the pulley driving the rotational shaft for rotating the conditioning head and for generating an error signal if the rotational speed of the pulley is deviated from a predetermined rotational speed range; and a control unit for receiving the error signals from the down-sensor unit and the up-sensor unit and applying alarm signals corresponding to the error signals to main equipment, and for displaying the rotational speed through the detection signal applied from the rotational speed detecting sensor unit, and for applying an alarm signal to the main equipment if the detected rotational speed is rapidly lowered.

[6] An error detecting apparatus according to claim 5, wherein the up-sensor unit comprises: a first magnetic installed at the rotational shaft; and a first magnetic sensor installed at a lower portion of the support portion so as to detect the first magnetic.

[7] An error detecting apparatus according to claim 5, wherein the down-sensor unit comprises: a second magnetic installed on the inner side of the conditioning head; and a second magnetic sensor installed at a lower portion of the support portion so as to detect the second magnetic.

[8] An error detecting apparatus according to claim 5, wherein the rotational speed detecting sensor unit comprises: a flag installed at a position adjacent to the pulley; and a sensor for detecting whether there is the flag.

[9] An error detecting apparatus according to claim 5, further comprising: a load cell installed at a clean cup, for detecting the pressure of the conditioning head moved down into the clean cup as the pad conditioner is moved to the clean cup to wash the conditioner pad, wherein the control unit receives an analog pressure signal detected by the load cell, converts the analog pressure signal to a digital pressure signal, displays the digital pressure signal, and applies the digital pressure signal to the main equipment.

[10] An error detecting apparatus according to one of claims 5 to 9, further comprising: a display panel for displaying signals applied from the down-sensor unit, the up- sensor unit, the rotational speed detecting sensor unit, and the load cell. [11] An error detecting apparatus according to one of claims 5 to 9, further comprising: an alarm means for alarming an operator on the basis of error signals applied from the down-sensor unit, the up-sensor unit, the rotational speed detecting sensor unit, and the load cell. [12] An error detecting apparatus according to claim 11, wherein the alarm means is a buzzer and/or an LED lamp.