JP6495117B2 - CMP polishing apparatus and CMP polishing method - Google Patents

Description

  The present invention relates to a CMP polishing apparatus and a CMP polishing method for polishing a wafer while supplying a slurry.

  In CMP (Chemical Mechanical Polishing) polishing, a wafer is sucked and held on a holding table, and a slurry is supplied with the polishing pad pressed against the wafer to polish the wafer. The holding surface of the holding table is formed of a porous body with poor heat escape, and there is a problem that the polishing rate is changed by warming the slurry by storing processing heat on the holding surface. For this reason, a CMP polishing apparatus is known that polishes a wafer while controlling the temperature during the polishing process (see, for example, Patent Document 1). The CMP polishing apparatus described in Patent Document 1 detects frictional heat during polishing using a temperature sensor, and controls polishing according to changes in frictional heat.

JP 2004-14999 A

  By the way, in the CMP polishing apparatus described in Patent Document 1, the temperature during polishing is controlled. However, if there is a deviation in parallelism between the polishing surface of the polishing pad and the surface of the wafer, the wafer is made uniform. It cannot be polished. For this reason, it has been important to adjust the parallelism between the polishing surface of the polishing pad and the holding surface of the holding table. Further, since the wafer is sucked and held on the holding table, a protective tape must be attached to the back surface of the wafer so that the wafer is not damaged by contact with the holding table. For this reason, there is a problem that the number of work steps and the material cost increase by the amount of use of the protective tape.

  The present invention has been made in view of the above points, and provides a CMP polishing apparatus and a CMP polishing method capable of polishing a wafer satisfactorily without adjusting parallelism and without increasing work man-hours and material costs. The purpose is to provide.

  The CMP polishing apparatus of the present invention includes a holding table having a holding surface facing the lower surface of the wafer, holding the wafer, a ring-shaped retainer ring having an inner diameter larger than the outer diameter of the wafer, and a wafer held by the holding table. An elevating mechanism that raises and lowers the retainer ring in the elevating direction that is perpendicular to the holding surface on the outside, a rotating means that rotates the wafer held by the holding table around the center of the wafer, and a polishing pad that polishes the wafer can be rotated Polishing means to be mounted on the surface, processing feed means for processing and feeding the polishing means and the holding table in directions approaching and separating from each other, slurry supply means for supplying slurry to the upper surface of the wafer and the polishing surface of the polishing pad, The holding table is provided with a spout for ejecting liquid from the holding surface, and is ejected from the spout along the holding surface. The wafer is carried toward the holding surface in a state of flowing through the body and filled with liquid, and the wafer flows in a gap between the lower surface of the wafer and the holding surface and is discharged from the outer periphery of the wafer to hold the wafer in a non-contact manner. To polish.

  According to this configuration, the liquid is interposed between the holding surface of the holding table and the lower surface of the wafer inside the retainer ring, and the wafer is held on the holding table in a non-contact manner. At the time of polishing, the wafer is pushed up by the liquid and pressed so that the upper surface of the wafer follows the polishing surface of the polishing pad. For this reason, even if there is a deviation in the parallelism between the holding surface of the holding table and the polishing surface of the polishing pad, the wafer can be satisfactorily polished without adjusting the parallelism. Further, since the lower surface of the wafer does not come into contact with the holding surface of the holding table and is damaged during polishing, it is not necessary to attach a protective tape to the lower surface of the wafer. Therefore, work man-hours and material costs can be reduced as much as the protective tape is not used.

  The CMP polishing apparatus further includes temperature adjusting means for adjusting the temperature of the liquid ejected from the ejection port.

  The CMP polishing method of the present invention is a CMP polishing method for polishing a wafer using the above-described CMP polishing apparatus, and is applied to a holding surface in a state filled with liquid by flowing a liquid along a holding surface and ejecting from a jet port. The wafer is carried in, the liquid flows through the gap between the lower surface of the wafer and the holding surface and is discharged from the outer periphery of the wafer, and the holding mechanism holds the wafer, and the lifting mechanism is used outside the wafer held in the holding process. A CMP polishing step in which after the retainer ring is raised, the polishing surface of the polishing pad is pressed against the retainer ring by the processing feed means and pressed onto the upper surface of the wafer, and the slurry is supplied by the slurry supply means to polish the wafer. It consists of

  In the CMP polishing method, in the CMP polishing step, the wafer is polished while adjusting the temperature of the liquid ejected from the ejection port to a predetermined temperature using the temperature adjusting means.

  According to the present invention, the liquid is interposed between the holding surface of the holding table and the lower surface of the wafer, and the wafer is held on the holding table in a non-contact manner. Therefore, the wafer can be polished satisfactorily without adjusting the parallelism between the holding surface of the holding table and the polishing surface of the polishing pad, and the work man-hours and material costs can be reduced by the amount not using the protective tape. it can.

1 is a perspective view of a CMP polishing apparatus according to a first embodiment. It is explanatory drawing of general CMP grinding | polishing. It is a perspective view which shows the periphery structure of the holding table which concerns on 1st Embodiment. It is explanatory drawing of the CMP grinding | polishing method which concerns on 1st Embodiment. It is explanatory drawing of the CMP grinding | polishing method which concerns on 2nd Embodiment. It is a perspective view which shows the periphery structure of the holding table which concerns on a modification.

  Hereinafter, a CMP polishing apparatus will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of a CMP polishing apparatus according to the first embodiment. Note that the CMP polishing apparatus according to the present embodiment is not limited to a polishing-dedicated apparatus as shown in FIG. 1, and is, for example, a fully automatic type in which a series of processes such as grinding, polishing, and cleaning are performed automatically. It may be incorporated in the processing apparatus.

  As shown in FIG. 1, the CMP polishing apparatus 1 causes the slurry to enter between the wafer W on the holding table 15 and the polishing pad 45, and polishes the wafer W by chemical mechanical polishing (CMP). It is configured. The wafer W may be a semiconductor substrate such as silicon or gallium arsenide, or may be an inorganic material substrate such as sapphire or silicon carbide. The wafer W may be a semiconductor wafer in which semiconductor devices such as IC and LSI are formed on a semiconductor substrate, or an optical device wafer in which optical devices such as LEDs are formed on an inorganic material substrate.

  A rectangular opening extending in the X-axis direction is formed on the upper surface of the base 10 of the CMP polishing apparatus 1, and this opening is covered with a table cover 11 movable together with the holding table 15 and a bellows-shaped waterproof cover 12. It has been broken. Below the waterproof cover 12, a moving means 20 for moving the holding table 15 in the X-axis direction and a rotating motor 25 as a rotating means for rotating the wafer W about the Z-axis are provided. As will be described later, a holding surface 16 that holds the wafer W in a non-contact manner is formed on the surface of the holding table 15. A retainer ring 30 for restricting excessive polishing on the wafer W is provided around the holding table 15 so as to be movable up and down.

  The moving means 20 includes a pair of guide rails 21 arranged on the base 10 and parallel to the X-axis direction, and a motor-driven X-axis table 22 slidably installed on the pair of guide rails 21. Yes. A nut portion (not shown) is formed on the back side of the X-axis table 22, and a ball screw 23 is screwed to the nut portion. Then, when the drive motor 24 connected to one end of the ball screw 23 is rotationally driven, the holding table 15 is moved along the pair of guide rails 21 in the X-axis direction. The rotation motor 25 is provided on the X-axis table 22 and is connected to a rotation base 52 provided below the holding table 15.

  The column 13 on the base 10 is provided with a processing feed means 35 for processing and feeding the polishing means 40 and the holding table 15 in the Z-axis direction relatively approaching and separating. The processing feed means 35 includes a pair of guide rails 36 arranged in the column 13 and parallel to the Z-axis direction, and a motor-driven Z-axis table 37 slidably installed on the pair of guide rails 36. . A nut portion (not shown) is formed on the back side of the Z-axis table 37, and a ball screw 38 is screwed to the nut portion. The ball screw 38 is rotationally driven by a drive motor 39 connected to one end of the ball screw 38, whereby the polishing means 40 is processed and fed along the guide rail 36.

  The polishing means 40 is attached to the front surface of the Z-axis table 37 via a housing 41, and is configured by rotatably mounting a polishing pad 45 on the lower part of the spindle unit. The spindle unit 42 is provided with a flange 43, and the polishing means 40 is supported on the housing 41 via the flange 43. A lower part of the spindle unit 42 is a mount 44, and a polishing pad 45 for polishing the wafer W is attached to the lower surface of the mount 44. The polishing pad 45 is formed of a foam material, fiber, or the like, and is mounted on the mount 44 so that the center of the polishing pad 45 and the center of the rotation shaft are aligned.

  A slurry supply means 61 for supplying slurry to the upper surface 71 of the wafer W and the polishing surface 46 of the polishing pad 45 is connected to the upper portion of the spindle unit 42. By supplying the slurry from the slurry supply means 61, the slurry is fixed to the polishing surface 46 through the flow path in the spindle unit 42. The slurry is an alkaline aqueous solution or an acidic aqueous solution containing abrasive grains, and contains, for example, abrasive grains of green carborundum, diamond, alumina, cerium oxide, and CBN (cubic boron nitride). The alkaline slurry is preferably used for polishing a silicon wafer, and the acidic slurry is preferably used for polishing an inorganic material wafer.

  The CMP polishing apparatus 1 is provided with a control unit (not shown) that controls each part of the apparatus. The control unit is configured by a processor, a memory, and the like that execute various processes. The memory is composed of one or a plurality of storage media such as a ROM (Read Only Memory) and a RAM (Random Access Memory) depending on the application. In the CMP polishing apparatus 1 configured as described above, the polishing pad 45 approaches the holding table 15 while being rotated about the Z axis. Then, the upper surface 71 of the wafer W is polished by the polishing pad 45 being in rotational contact with the wafer W while the slurry is supplied.

  By the way, in a general CMP polishing apparatus as shown in FIG. 2, the protective tape T is stuck to the lower surface 72 of the wafer W, and the wafer W is sucked and held on the holding table 15 via the protective tape T. It is polished with. In this case, since the upper surface 71 of the wafer W is deformed following the holding surface 16 of the holding table 15, the wafer W is moved when the polishing surface 46 of the polishing pad 45 and the holding surface 16 of the holding table 15 are not parallel. It is difficult to process uniformly. Further, since the protective tape T is attached to the lower surface 72 of the wafer W, the number of work steps such as attaching the protective tape T and removing the protective tape T increase, and the material cost increases.

  Therefore, in the present embodiment, the ejection port 17 (see FIG. 1) connected to the liquid supply source 62 (see FIG. 1) is provided in the holding table 15, and the holding surface 16 and the wafer of the holding table 15 are connected from the ejection port 17. By supplying a liquid to the lower surface 72 of W, the wafer W is held on the holding table 15 in a non-contact manner. As a result, the wafer W can be uniformly polished without adjusting the parallelism of the holding surface 16 of the holding table 15 and the polishing surface 46 of the polishing pad 45, and the work man-hours and material costs can be reduced by the amount not using the protective tape T. Reduced. Since the lower surface 72 of the wafer W is liquid-cleaned during polishing, the polishing debris does not adhere to the lower surface 72 of the wafer W.

  In CMP polishing, the wafer W is mechanically polished by the abrasive grains in the slurry while being etched by the chemical components of the slurry. The chemical components of the slurry vary in the degree of activation depending on the temperature, resulting in a difference in the amount of progress of etching with respect to the wafer W. For this reason, it is preferable that the slurry is supplied to the wafer W in a temperature-controlled state so as to achieve an appropriate polishing rate (polishing amount per unit time). For this reason, in the present embodiment, the temperature of the liquid ejected from the ejection port 17 is adjusted by the temperature adjusting means 63 (see FIG. 1), so that the temperature of the slurry is indirectly adjusted by the liquid.

  Hereinafter, the peripheral configuration of the holding table will be described with reference to FIG. FIG. 3 is a perspective view showing a peripheral configuration of the holding table according to the first embodiment.

  As shown in FIG. 3, the holding table 15 has a holding surface 16 that faces the lower surface 72 of the wafer W, and is configured to hold the wafer W in a non-contact manner on the holding surface 16. The holding table 15 is formed with an annular jet 17 for ejecting liquid from the holding surface 16, and a liquid supply source 62 for supplying liquid is connected to the jet 17. The liquid ejected from the ejection port 17 flows along the holding surface 16 so that the holding surface 16 is filled with the liquid. When the wafer W is loaded toward the holding surface 16, the liquid flows into the gap between the lower surface 72 of the wafer W and the holding surface 16 of the holding table 15, and is discharged from the outer peripheral side of the wafer W. The wafer W is held in contact with 16.

  In this case, since the retainer ring 30 is lowered during conveyance and the flow velocity is high, a negative pressure is generated on the holding surface 16 of the holding table 15 by the Bernoulli effect, and the wafer W is sucked and held (see FIG. 4A). On the other hand, during the polishing, the retainer ring 30 is raised and the flow velocity is reduced. Therefore, the wafer W is pressed against the polishing pad 45 by the liquid, so that the wafer W is held against the holding surface 16 in a non-contact manner (see FIG. 4C). As shown in FIG. 6, even during polishing, an escape passage 33 is formed in the retainer ring 30 so as not to decrease the flow rate of the liquid, and the wafer W is not in contact with the holding surface 16 by the Bernoulli effect as in the case of conveyance. It may be held. When the retainer ring 30 is provided with a liquid escape path 33, when the retainer ring 30 is raised during the transportation and the liquid is ejected from the ejection port 17, the wafer W is horizontally moved from the holding surface 16 by the liquid ejected from the ejection port 17. Even if it moves to, there is no fear of falling from the holding surface 16. The escape passage 33 is a groove formed on the upper surface of the retainer ring 30, and is formed so as to cross the upper surface of the retainer ring 30 obliquely so as to follow the flow of liquid from the ejection port 17.

  Around the holding table 15, a ring-shaped retainer ring 30 having an inner diameter larger than the outer diameter of the wafer W is provided. A flat portion 31 that can be engaged with an orientation flat 73 of the wafer W is formed on the inner peripheral surface of the retainer ring 30. Below the retainer ring 30, there are a plurality of (four in the present embodiment) lift mechanisms that raise and lower the retainer ring 30 in the lift direction that is perpendicular to the holding surface 16 outside the wafer W (holding table 15). Cylinder 32 is provided. By raising the retainer ring 30, excessive polishing of the wafer W by the polishing pad 45 (see FIG. 4C) is restricted on the upper surface of the retainer ring 30.

  The holding table 15 is supported by a cylindrical support column 51, and a rotation base 52 is provided so as to surround the support column 51. The rotation base 52 is configured by rotatably mounting a ring-shaped movable base 54 on a ring-shaped fixed base 53. Around the rotation base 52, a rotation motor 25 is arranged as a rotation means for rotating the wafer W around the center of the wafer W. The main drive gear 26 of the rotary motor 25 is meshed with a driven gear 55 formed on the outer peripheral surface of the movable table 54, and the retainer ring 30 is rotated via the movable table 54 by the driving force of the rotary motor 25.

  At the time of polishing the wafer W, the retainer ring 30 is raised in a state where the space between the lower surface 72 of the wafer W and the holding surface 16 of the holding table 15 is filled with liquid. When the rotary motor 25 is rotated, the retainer ring 30 is rotated via the movable base 54. As described above, the flat portion 31 is formed on the inner peripheral surface of the retainer ring 30, and the wafer W rotates with the retainer ring 30 by engaging the flat portion 31 of the retainer ring 30 with the orientation flat 73. In this state, the polishing surface 46 of the rotated polishing pad 45 is brought into rotational contact with the upper surface 71 of the wafer W to polish the wafer W.

  During this polishing, the wafer W is held on the holding table 15 in a non-contact manner so that the upper surface 71 of the wafer W is pressed against the polishing surface 46 of the polishing pad 45. Therefore, regardless of the parallelism of the holding surface 16 of the holding table 15 and the polishing surface 46 of the polishing pad 45, uniform polishing is possible without causing a thickness difference between the inner and outer peripheral sides of the wafer W ( (See FIG. 4C). Further, the retainer ring 30 restricts excessive polishing of the polishing pad 45 with respect to the wafer W, so that only the outer peripheral side of the wafer W is not excessively polished. Further, since the wafer W can be held without sticking the protective tape T (see FIG. 2), it is possible to reduce the work man-hours and material costs.

  Further, at the time of polishing, the polishing rate changes according to the temperature of the slurry between the wafer W and the polishing pad 45, so the temperature of the slurry is indirectly adjusted by the temperature adjusting means 63. In this case, the temperature of the liquid supplied from the liquid supply source 62 is adjusted by the temperature adjusting means 63, and the temperature of the slurry is adjusted via the wafer W in contact with the liquid. The polishing rate is appropriately controlled by adjusting the temperature of the slurry through the liquid by the temperature adjusting means 63 while detecting the thickness of the wafer W with a thickness sensor (not shown). For example, in the early stage of polishing, the temperature of the slurry is raised and the polishing rate is controlled to be high, and the temperature of the slurry is lowered toward the final stage of polishing and the polishing rate is controlled to be low.

  The CMP polishing method will be described in detail with reference to FIG. FIG. 4 is an explanatory diagram of the CMP polishing method according to the first embodiment. 4A shows the holding process, and FIGS. 4B and 4C show the CMP polishing process.

  As shown in FIG. 4A, a holding step is first performed. In the holding step, the retainer ring 30 is lowered by the cylinder 32, and the liquid is ejected from the ejection port 17 at the center of the holding surface 16 at a high flow rate and discharged from the outer peripheral side of the holding surface 16 to the outside. As a result, a liquid flow from the center of the holding surface 16 toward the outer peripheral side is formed, and a liquid layer is formed so as to cover the entire surface of the holding surface 16. When the wafer W is carried into the holding surface 16 filled with the liquid, a negative pressure is generated by the liquid flowing between the lower surface 72 of the wafer W and the holding surface 16 of the holding table 15, and the wafer W is held on the holding surface 16. 16 is adsorbed by Bernoulli and held without contact. As shown in FIG. 6, when the retainer ring 30 includes the escape passage 33, the liquid is not discharged from the escape passage 33 and the flow rate of the liquid ejected from the ejection port 17 is not reduced. The wafer W is Bernoulli adsorbed to the holding surface 16 and held in a non-contact manner.

  As shown in FIG. 4B, a CMP polishing step is performed after the holding step. In the CMP polishing step, the wafer W is transported to just below the polishing means 40 with the wafer W adsorbed on the holding surface 16 of the holding table 15. The retainer ring 30 is raised by the cylinder 32, and the retainer ring 30 is positioned around the wafer W. Since the liquid flow is partially blocked by the retainer ring 30, the liquid flow is slowed and the Bernoulli adsorption is released. Even in the state where the Bernoulli adsorption is released, the wafer W is pushed up by the liquid, and the wafer W is held on the holding surface 16 in a non-contact manner inside the retainer ring 30.

  As shown in FIG. 4C, when the rotation of the rotary motor 25 is transmitted to the retainer ring 30 via the rotation base 52, the wafer W inside the retainer ring 30 is rotated along with the rotation of the retainer ring 30. Further, the rotated polishing pad 45 is processed and fed toward the wafer W by the processing feeding means 35, and the retainer ring 30 is pressed and the wafer W is pressed by the polishing surface 46 of the polishing pad 45. While the slurry is supplied from the slurry supply means 61 between the polishing surface 46 of the polishing pad 45 and the upper surface 71 of the wafer W, the polishing surface 46 of the polishing pad 45 and the upper surface 71 of the wafer W are rotationally contacted and polished. .

  At this time, the upper surface 71 of the wafer W is pressed by the liquid so as to follow the polishing surface 46 of the polishing pad 45. Since the upper surface 71 of the wafer W is in contact with the polishing surface 46 of the polishing pad 45 in parallel, the wafer W is uniformly polished on the inside and outside of the wafer W. During polishing, the lower surface 72 of the wafer W does not come into contact with the holding surface 16 of the holding table 15, and the lower surface 72 of the wafer W is always washed with liquid. There is nothing to do. Furthermore, since the lower surface 72 of the wafer W does not come into contact with the holding surface 16 and is not damaged, it is not necessary to attach the protective tape T (see FIG. 2) to the lower surface 72 of the wafer W.

  In such CMP polishing, the thickness of the wafer W is detected in real time by the thickness sensor, and the polishing rate is controlled by adjusting the temperature of the slurry according to the thickness of the wafer W. For example, in the early stage of polishing, the target temperature of the slurry is set to the first target temperature having a high polishing rate, and the temperature of the liquid is adjusted to be high by the temperature adjusting means 63. The heat of the liquid is transferred to the slurry via the wafer W, so that the wafer W is polished relatively coarsely by the warmed slurry. This rough polishing is continued until the thickness of the wafer W at the end of polishing is detected by the thickness sensor.

  At the final stage of polishing, the target temperature of the slurry is switched to the second temperature having a low polishing rate, and the temperature of the liquid is adjusted to be low by the temperature adjusting means 63. The temperature of the slurry is lowered to the second target temperature due to the temperature drop of the liquid, and the wafer W is polished at a normal polishing rate. Thereby, the activation of the chemical components of the slurry is suppressed by the decrease in the target temperature, and the wafer W is prevented from being excessively polished in the finishing stage. In this way, by increasing the polishing rate at the beginning of polishing and decreasing the polishing rate at the end of polishing, it is possible to reduce the polishing processing time without reducing the polishing accuracy.

  As described above, in the CMP polishing apparatus 1 according to the first embodiment, liquid is interposed between the holding surface 16 of the holding table 15 and the lower surface 72 of the wafer W inside the retainer ring 30, and the holding table 15. The wafer W is held in a non-contact manner. During polishing, the wafer W is pushed up by the liquid, and the upper surface 71 of the wafer W is pressed so as to follow the polishing surface 46 of the polishing pad 45. For this reason, even if the parallelism between the holding surface 16 of the holding table 15 and the polishing surface 46 of the polishing pad 45 is deviated, the wafer W can be satisfactorily polished without adjusting the parallelism. Further, since the lower surface 72 of the wafer W does not come into contact with the holding surface 16 of the holding table 15 and is not damaged during polishing, it is not necessary to attach the protective tape T (see FIG. 2) to the lower surface 72 of the wafer W. Therefore, work man-hours and material costs can be reduced as much as the protective tape T is not used.

  Next, a CMP polishing apparatus according to the second embodiment will be described with reference to FIG. The CMP polishing apparatus according to the second embodiment is different from the first embodiment in that the holding table rotates together with the retainer ring. Therefore, only differences from the first embodiment will be described, and description of common configurations will be omitted as much as possible. The same components as those in the first embodiment will be described with the same reference numerals. FIG. 5 is an explanatory diagram of a CMP polishing method according to the second embodiment.

  As shown in FIG. 5, in the CMP polishing apparatus according to the second embodiment, the shaft portion 18 protrudes directly below the center of the lower surface of the holding table 15, and the shaft portion 18 projects from the support base 56 on the X-axis table 22. Is rotatably supported via a bearing 57. An annular flange 58 is fixed to the lower surface of the holding table 15, and a plurality of (four in the present embodiment) cylinders 32 are provided on the flange 58 as lifting mechanisms for lifting and lowering the retainer ring 30. ing. A rotation motor 25 is connected to the shaft portion 18 of the holding table 15 as a rotating means for rotating the retainer ring 30 together with the holding table 15.

  Also in the CMP polishing apparatus configured as described above, the same CMP polishing method as that of the CMP polishing apparatus 1 according to the first embodiment is performed. As shown in FIG. 5A, in the holding step, the retainer ring 30 is lowered by the cylinder 32, the liquid is ejected from the ejection port 17 of the holding table 15 at a high flow velocity, and the wafer W is adsorbed on the holding surface 16 and is not absorbed. Held in contact. As shown in FIG. 5B, in the CMP polishing process, when the wafer W is conveyed to just below the polishing means 40, the retainer ring 30 is raised by the cylinder 32, and the inner side of the retainer ring 30 is released in a state where the Bernoulli adsorption is released. Thus, the wafer W is held on the holding surface 16 in a non-contact manner.

  As shown in FIG. 5C, the retainer ring 30 is rotated together with the holding table 15 by the rotation motor 25, and the wafer W is rotated around the retainer ring 30. Further, the polishing pad 45 is processed and fed toward the wafer W by the processing feeding means 35 while rotating, and the retainer ring 30 is pressed and the wafer W is pressed by the polishing surface 46 of the polishing pad 45. Then, while the slurry is supplied from the slurry supply means 61, the polishing surface 46 of the polishing pad 45 and the upper surface 71 of the wafer W are rotationally contacted and polished. At this time, as in the first embodiment, the polishing rate may be controlled while adjusting the temperature of the liquid.

  As described above, also in the CMP polishing apparatus according to the second embodiment, the liquid is interposed between the holding surface 16 of the holding table 15 and the lower surface 72 of the wafer W, so that the wafer W does not contact the holding table 15. Retained. Therefore, as in the first embodiment, the wafer W can be satisfactorily polished without adjusting the parallelism between the holding surface 16 of the holding table 15 and the polishing surface 46 of the polishing pad 45, and the protective tape T The number of work steps and material costs can be reduced by the amount of not using. Further, the lower surface 72 of the wafer W can be polished while being washed.

  In addition, this invention is not limited to the said embodiment, It can change and implement variously. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the first and second embodiments described above, the annular ejection port 17 is provided on the holding surface 16 of the holding table 15, but the present invention is not limited to this configuration. The spout 17 may have any shape that creates a liquid flow from the center of the holding surface 16 toward the outer periphery, and the shape is not particularly limited. Further, a plurality of jets 17 may be formed on the holding surface 16 of the holding table 15 instead of the single jets 17.

  In the first and second embodiments described above, the plurality of cylinders 32 are exemplified as the lifting mechanism, but the present invention is not limited to this configuration. The raising / lowering mechanism should just be the structure which raises / lowers the retainer ring 30 in the raising / lowering direction, for example, may be comprised by the electric actuator.

  In the first and second embodiments described above, the polishing feed unit 35 is processed and fed in the direction in which the polishing unit 40 approaches and separates from the holding table 15 by the processing feed unit 35. However, the configuration is limited to this configuration. Not. The process feeding means 35 may be configured to process and feed the holding table 15 toward and away from the polishing means 40.

  Further, in the first and second embodiments described above, the flat portion 31 is formed on the inner peripheral surface of the retainer ring 30 corresponding to the orientation flat 73 of the wafer W. It is not limited. An engagement portion that engages with a notch portion of the wafer W may be formed on the inner peripheral surface of the retainer ring 30. For example, when the notch is formed in the wafer W, the retainer ring 30 has a notch. A protrusion may be formed on the inner peripheral surface as an engaging portion corresponding to the notch. Further, as long as the wafer W can be rotated with the retainer ring 30, the engaging portion may not be formed on the inner peripheral surface of the retainer ring 30.

  In the first and second embodiments described above, the slurry is indirectly heated by adjusting the temperature of the liquid. However, the present invention is not limited to this configuration. The temperature of the slurry may be adjusted by heating the slurry directly with the slurry supply means 61 and absorbing the heat of the slurry by the liquid. For example, the temperature of the liquid may be increased at the beginning of polishing to suppress the decrease in the temperature of the slurry, and the temperature of the liquid may be decreased at the end of polishing to decrease the temperature of the slurry. In the first and second embodiments, the temperature of the slurry may not be adjusted.

  In the first and second embodiments described above, the CMP polishing apparatus 1 is described as an example. However, the CMP polishing apparatus 1 is a fully automatic type process in which a series of processes are performed fully automatically. It may be incorporated into the device.

  In the first and second embodiments described above, the configuration in which the polishing pad 45 is positioned above the holding table 15 and the wafer W is polished from the upper side has been described. However, the present invention is not limited to this configuration. The holding surface 16 of the holding table 15 may be directed downward, the polishing pad 45 may be positioned below the holding table 15, and the wafer W may be polished from below.

  As described above, the present invention has an effect that the wafer can be satisfactorily polished without adjusting the parallelism and without increasing the work man-hours and the material cost. However, it is useful for a CMP polishing apparatus and a CMP polishing method for polishing a wafer.

DESCRIPTION OF SYMBOLS 1 CMP polishing apparatus 15 Holding table 16 Holding surface 17 Jet outlet 25 Rotation motor (rotating means)
30 Retainer ring 32 Cylinder (elevating mechanism)
35 Process Feeding Unit 40 Polishing Unit 45 Polishing Pad 46 Polishing Surface of Polishing Pad 61 Slurry Supplying Unit 63 Temperature Control Unit 71 Wafer Upper Surface 72 Wafer Lower Surface W Wafer

Claims (4)

A holding table having a holding surface facing the lower surface of the wafer and holding the wafer, a ring-shaped retainer ring having an inner diameter larger than the outer diameter of the wafer, and perpendicular to the holding surface outside the wafer held by the holding table A lifting mechanism that lifts and lowers the retainer ring in a lifting direction, a rotating means that rotates the wafer held by the holding table about the center of the wafer, and a polishing that rotatably mounts a polishing pad that polishes the wafer Means, processing feed means for processing and feeding the polishing means and the holding table relatively in the approaching and separating directions, slurry supply means for supplying slurry to the upper surface of the wafer and the polishing surface of the polishing pad, With
The holding table includes a jet outlet for ejecting liquid from the holding surface,
The liquid is ejected from the ejection port and flows along the holding surface, and the wafer is loaded toward the holding surface filled with the liquid. The liquid flows through the gap between the lower surface of the wafer and the holding surface. A CMP polishing apparatus for polishing a wafer while holding the wafer in a non-contact manner by discharging it from the outer periphery of the wafer.   The CMP polishing apparatus according to claim 1, further comprising temperature adjusting means for adjusting a temperature of the liquid ejected from the ejection port. A CMP polishing method for polishing a wafer using the CMP polishing apparatus according to claim 1 or 2,
The liquid is ejected from the ejection port and flows along the holding surface, and the wafer is loaded toward the holding surface filled with the liquid. The liquid flows through the gap between the lower surface of the wafer and the holding surface. A holding step for holding the wafer by discharging it from the outer periphery of the wafer;
After the retainer ring is lifted by using the lifting mechanism outside the wafer held in the holding step, the polishing surface of the polishing pad is pressed against the retainer ring by the processing feeding means, and the upper surface of the wafer is CMP polishing step of pressing and further polishing the wafer by supplying slurry by the slurry supply means;
A CMP polishing method comprising:   4. The CMP polishing method according to claim 3, wherein, in the CMP polishing step, the wafer is polished while adjusting the temperature of the liquid ejected from the ejection port to a predetermined temperature using temperature control means.

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