Semiconductor manufacturing apparatus and method of manufacturing semiconductor device

Abstract

Embodiments provide a semiconductor manufacturing apparatus capable of performing detailed temperature distribution control in a wafer in-plane, and a manufacturing method of a semiconductor device capable of improving in-plane uniformity of a polishing rate. The semiconductor manufacturing apparatus of the embodiments is a semiconductor manufacturing apparatus that polishes a surface of a polishing object held by a polishing head. The semiconductor manufacturing apparatus of the embodiments has a plurality of laser irradiation sections in the polishing head. In the semiconductor manufacturing apparatus of the embodiments, at least one of the laser irradiation sections is a laser irradiation section that irradiates a laser beam to a back surface side of the polishing object.

Description

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS]

[0002] This application claims priority to Japanese Patent Application No. 2022-036600 (Filing date: March 9, 2022). This application incorporates by reference the entire contents of the base application. TECHNICAL FIELD

[0003] Embodiments relate to a semiconductor manufacturing apparatus and a manufacturing method of a semiconductor device. BACKGROUND

[0004] In a CMP apparatus (chemical mechanical polishing apparatus), in order to promote a chemical reaction, control a polishing rate, a technique of heating a polishing surface to perform temperature control is being put into practical use. So far, a method of providing a heat exchanger on a polishing pad, a mechanism of spraying high-temperature vapor on a polishing pad are being put into practical use.

[0005] In the related art, there is a problem that detailed temperature distribution control in a wafer surface cannot be performed, and in-plane uniformity of a polishing rate is deteriorated. In addition, in the related art, temperature control is performed by heat exchange, so there is also a problem that temperature cannot be rapidly increased. Furthermore, in the related art, while slurry is supplied to a polishing stage, a wafer is pressed against the polishing stage by a polishing pad to perform polishing, but there is a problem that slurry inflow is hindered or slurry concentration is reduced, and thus polishing characteristics are greatly changed. SUMMARY

[0006] An object of the present application is to provide a semiconductor manufacturing apparatus and a manufacturing method of a semiconductor device capable of performing detailed temperature distribution control in a wafer surface, and capable of improving in-plane uniformity of a polishing rate.

[0007] The semiconductor manufacturing apparatus of the embodiment is a semiconductor manufacturing apparatus that polishes a surface of a polishing target held by a polishing head. The semiconductor manufacturing apparatus of the embodiment has a plurality of laser irradiation sections in the polishing head. In the semiconductor manufacturing apparatus of the embodiment, at least one of the laser irradiation sections is a laser irradiation section that irradiates a laser beam to a back surface side of the polishing target. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a cross-sectional schematic view showing a first embodiment of a polishing apparatus.

[0009] Figure 2 is a cross-sectional schematic view showing a first embodiment of a polishing apparatus. Figure 1 is a cross-sectional schematic view showing a first embodiment of a polishing apparatus.

[0010] Figure 3 is a cross-sectional schematic view showing a first embodiment of a polishing apparatus.Figure 1 Fig. 2 is a plan view of the laser irradiation section of the polishing apparatus shown in Fig. 1.

[0011] Figure 4 Fig. 3 is a graph showing an example of frequency dependence of the extinction coefficient of silicon with respect to water.

[0012] Figure 5 Fig. 4 is a conceptual view showing an example of a state in which the wafer is heated by laser irradiation.

[0013] Figure 6 Fig. 5 is a configuration view showing a second embodiment of the polishing apparatus.

[0014] Figure 7 Fig. 6 is a configuration view showing a third embodiment of the polishing apparatus.

[0015] Figure 8 Fig. 7 is a cross-sectional schematic view showing an example of a polishing target object before polishing.

[0016] Figure 9 Fig. 8 is a cross-sectional schematic view showing an example of the polishing target object in the middle of polishing.

[0017] Figure 10 Fig. 9 is a cross-sectional schematic view showing an example of the polishing target object after polishing. DETAILED DESCRIPTION

[0018] "First Embodiment"

[0019] Hereinafter, a polishing apparatus according to a first embodiment will be described with reference to the drawings. In the following description, the same reference numerals are assigned to components having the same or similar functions. Moreover, the repeated description of those components will be omitted at times. In the present specification, the term "adjacent" is not limited to the case where the components are adjacent to each other, but includes the case where other components are present between the two components that are the objects. In the present specification, the term "xx is provided on yy" is not limited to the case where xx is in contact with yy, but includes the case where other components are interposed between xx and yy. In the present specification, the terms "parallel" and "orthogonal" respectively include the cases of "substantially parallel" and "substantially orthogonal".

[0020] Further, first, the X direction, the Y direction, and the Z direction will be defined. The X direction and the Y direction are directions along the flat upper surface of the circular plate-shaped stage 1 described below. The Y direction is a direction that intersects (e.g., is orthogonal to) the X direction. The Z direction is a direction that intersects (e.g., is orthogonal to) the X direction and the Y direction, and is the thickness direction of the circular plate-shaped stage 1, which is equivalent to the vertical direction. In the present specification, the "+Z direction" will be referred to as "up", and the "-Z direction" will be referred to as "down". The +Z direction and the -Z direction are directions that differ by 180°.

[0021] Figure 1is a sectional view of a semiconductor manufacturing apparatus (polishing apparatus) A of Embodiment 1.

[0022] The semiconductor manufacturing apparatus A has a circular plate-shaped rotatable stage 1 arranged horizontally, and a polishing pad 2 arranged on the upper surface of the stage 1. A slurry nozzle 3 is arranged above the polishing pad 2, and a desired amount of slurry 4 can be supplied from the slurry nozzle 3 to the polishing pad 2. The polishing pad 2 is formed in a circular sheet shape having substantially the same diameter as the upper surface of the stage 1. The polishing pad 2 is formed of, for example, a foamed urethane resin or the like. The polishing pad 2 is attached to the upper surface of the stage 1 in a detachable manner in this example.

[0023] A rotation shaft 1A extending in the Z direction is attached to the central portion of the lower surface of the stage 1, and the stage 1 is rotatably supported about the rotation shaft 1A. A drive device including a motor or the like that rotates the rotation shaft 1A is arranged below the rotation shaft 1A, but the drive device is omitted in Figure 1 , and only the upper end portion of the rotation shaft 1A is depicted.

[0024] The slurry nozzle 3 is arranged in a vertically downward manner with the front end portion 3a of the slurry nozzle 3 arranged at a specific interval above the center of the stage 1. Since the stage 1 and the polishing pad 2 rotate simultaneously, the slurry 4 dropped from the slurry nozzle 3 to the center of the upper surface of the polishing pad 2 can flow in a manner that gradually spreads along the upper surface of the polishing pad 2 in the circumferential direction of the polishing pad 2 by the centrifugal force. In addition, Figure 1 The slurry nozzle 3 is one example, and the slurry nozzle 3 can be arranged at any position and in any direction as long as the slurry 4 can be supplied to the upper surface of the polishing pad 2.

[0025] The slurry 4 is a viscous liquid formed by dispersing a desired amount of particles of a polishing material used for polishing in a liquid such as a solvent.

[0026] In Figure 1 , above the stage 1 and between the position at which the slurry nozzle 3 is arranged and the outer periphery of the stage 1, a circular plate-shaped wafer (semiconductor substrate) 5, a circular plate-shaped pocket 7, and a circular plate-shaped polishing head 6 are arranged in this order from the lower side. In Figure 1 the example shown, the polishing head 6 is formed to have a diameter slightly smaller than the radius of the stage 1, and the wafer 5 and the pocket 7 are formed to have diameters slightly smaller than the diameter of the polishing head 6. The diameter of the wafer 5 is formed to be substantially equal to the diameter of the pocket 7. In Figure 1 the example shown, the polishing head 6, the wafer 5, and the pocket 7 are arranged on the -X direction side (left side) from the center of the stage 1.

[0027] The wafer 5 is disposed substantially horizontally on the upper surface of the polishing pad 2 with its surface (bottom surface) 5a in contact with the upper surface of the polishing pad 2. The polishing head 6 is disposed horizontally on the back surface (upper surface) 5b of the wafer 5 with the disc-shaped bag 7 interposed therebetween. The polishing head 6 has a circular plate-shaped main body portion 6A with a rotary shaft 6B extending in the Z direction mounted at the center of the upper surface side thereof.

[0028] The rotary shaft 6B is connected to a rotary drive mechanism provided with a motor or the like in Figure 1 The rotary drive mechanism is omitted from the description. The rotary drive mechanism is capable of rotating the rotary shaft 6B independently of the rotation of the stage 1, so the stage 1 and the polishing head 6 are rotated individually. In addition, the polishing head 6 and the rotary shaft 6B are supported by a support mechanism (not shown) in the space above the stage 1 so as to be movable in the Z direction and the XY direction, and are configured so as to be capable of approaching and separating the polishing head 6 from the upper surface of the polishing pad 2 and being positioned at an arbitrary position.

[0029] A plurality of laser irradiation portions 9 are assembled on the main body portion 6A of the polishing head 6 from the center of the lower surface of the main body portion 6A toward the outer peripheral portion of the lower surface. A retaining ring 8 is mounted on the outer peripheral edge portion of the main body portion 6A outside the region in which the laser irradiation portions 9 are disposed. The retaining ring 8 includes a ring body having the same height as the polishing head 6.

[0030] A downwardly extending annular groove portion 6C is formed on the outer peripheral edge portion of the lower surface of the polishing head 6, and the retaining ring 8 is disposed along the groove portion 6C. The retaining ring 8 is mounted in such a manner that the upper side of the retaining ring 8 is housed in the deep side of the groove portion 6C and the lower side of the retaining ring 8 protrudes downward from the lower surface opening portion of the groove portion 6C by a certain length. An annular elastic member 10 is interposed between the upper side of the retaining ring 8 and the inner deep side of the groove portion 6C. The lower end portion of the retaining ring 8 protrudes downward from the lower surface of the polishing head 6 by a certain length, and the wafer 5 and the bag 7 are disposed inside the retaining ring 8 that protrudes downward from the polishing head 6.

[0031] The inner peripheral side of the lower end of the retaining ring 8 is disposed so as to surround the outer peripheral side of the wafer 5 and the bag 7 with a slight gap. As described below, in the case of polishing the wafer 5, the retaining ring 8 suppresses the wafer 5 and the bag 7 from jumping out to the outside.

[0032] The laser irradiation portions 9 assembled on the polishing head 6 are Figure 1 are omitted in the cross section shown. As shown in the plan view of the bottom surface of the polishing head 6 Figure 3 are omitted in the cross section shown. As shown in the plan view of the bottom surface of the polishing head 6

[0033] The laser irradiation portions 9 assembled on the polishing head 6 are Figure 3In the example shown, on the bottom surface of the grinding head 6, a plurality of laser irradiation portions 9 are arranged relatively closely, such that the interval between the laser irradiation portions 9, 9 that are closest to each other in the radial and circumferential directions on the bottom surface is smaller than the diameter of each laser irradiation portion 9. Furthermore, the arrangement of the plurality of laser irradiation portions 9 is not limited to... Figure 3 As shown in the example, any configuration can be selected as long as it allows each laser irradiation unit 9 to be arranged close together. The front end faces of all laser irradiation units 9 are arranged such that they are approximately flush with the bottom surface 6D of the grinding head 6.

[0034] also, Figures 1-3 Each laser irradiation unit 9 shown is connected to an infrared laser source (IR source, omitted in the accompanying drawings) via a transmission path such as an optical fiber. This configuration allows the laser beam (infrared light) transmitted from the laser source (omitted in the drawings) via the transmission path to exit from the front end of each laser irradiation unit 9. Furthermore, although omitted in the drawings, a focusing optical system, such as a focusing lens, is assembled at the front end of each laser irradiation unit 9, enabling the laser beam (IR light) to exit from the front end of the laser irradiation unit 9. Figure 2 The illustrated focused laser beam is emitted in front of the laser irradiation unit 9.

[0035] exist Figure 2 The text indicates a downward-facing configuration of the laser irradiation unit 9, depicted as a downward-facing laser beam gradually narrowing and the optical path width of the laser beam gradually decreasing. Additionally, as... Figure 1 and Figure 2 As shown, with the grinding head 6 in place, the aperture of the laser beam is set so that the focal position of the laser beam is approximately aligned with the slurry 4 or the grinding pad 2.

[0036] Furthermore, ideally, the wavelength of the laser beam irradiated from the laser irradiation unit 9 is in the range of 2.5 μm to 3.5 μm, or in the range of 5.5 μm to 6.5 μm, or in the range of 10 μm or more. Examples of laser elements capable of emitting laser beams with these wavelengths include YAG lasers (yttrium aluminum garnet lasers), YSGG lasers (yttrium scandium gallium garnet lasers), ZBLAN lasers (fluoride glass lasers), YLF lasers (yttrium lithium fluoride lasers), and CO2 lasers.

[0037] Bag 7 is a bag made of a thin film of infrared (IR)-transmitting silicone rubber, such as silicone rubber without silica particles. A fluid injection device (air injection device, not shown in the diagram) is connected to bag 7 to inject fluid such as air into the interior of bag 7, thus adjusting the thickness of bag 7. If it is a thin film such as silicone rubber without silica particles, then the transmittance is over 90% for a wide wavelength range of light in the infrared region, which is ideal.

[0038] Therefore, by adjusting the thickness (bulging amount) of the bag 7, it is possible to press the upper surface of the bag 7 against the bottom surface 6D of the polishing head 6 and press the lower surface of the bag 7 against the upper surface of the wafer 5. Thus, it is possible to press the lower surface of the wafer 5 against the upper surface of the polishing pad 2 with a specific pressure. That is, by adjusting the amount of fluid supplied to the bag 7, it is possible to adjust the pressing force of the bag 7 against the surface 5a of the wafer 5 in the case where the bag 7 is pressed against the polishing pad 2.

[0039] Further, the force with which the bag 7 presses the wafer 5 against the polishing pad 2 does not need to be fixed all the time but can be changed as appropriate, for example, as the polishing progresses.

[0040] Further, it is also possible to form a configuration in which the inside of the bag 7 is partitioned into a plurality of regions. By being partitioned into a plurality of regions, it is possible to adjust the fluid pressure for each of the partitioned regions and adjust the pressing force against the wafer 5 for each region. Thus, for example, in the case where the lower surface of the wafer 5 is pressed against the upper surface of the polishing pad 2, in the case where the lower surface of the wafer 5 is inclined with respect to the upper surface of the polishing pad 2, the fluid pressure of each of the plurality of regions is adjusted in such a way as to correct the inclination, and thus it is possible to correct the inclination.

[0041] The wafer 5 is composed of, for example, a semiconductor substrate such as a silicon substrate that is transparent to infrared rays (IR light). Therefore, the wavelength of the laser beam R is a wavelength that is transparent to the semiconductor substrate and is in the infrared region.

[0042] In the case where the bag 7 and the wafer 5 are composed of the material, if a laser beam of the wavelength is used as the laser beam, the laser beam that is irradiated to the back surface 5b side of the wafer 5 can surely reach the slurry 4 or the polishing pad 2 through the bag 7 and the wafer 5. Thus, the laser beam can heat the slurry 4 or the polishing pad 2.

[0043] In order to perform polishing of the wafer 5 using the semiconductor manufacturing apparatus A, the rotation of the stage 1 is stopped so as to become Figure 1 The wafer 5 and the bag 7 are stacked on the upper surface of the polishing pad 2 in the state shown in the drawing, and the retaining ring 8 is positioned so as to surround the periphery thereof. The polishing head 6 that is positioned above the wafer 5 and the bag 7 is lowered so as to surround the wafer 5 and the bag 7 on the lower side of the retaining ring 8, and the lower surface of the wafer 5 is pressed against the upper surface of the polishing pad 2 by the bag 7 to which a specific fluid pressure is applied. The slurry for polishing is supplied to the upper surface of the polishing pad 2 from the slurry nozzle 3, the stage 1 is rotated, and the polishing head 6 is also rotationally driven.

[0044] By the above operation, the surface 5a of the wafer 5 can be pressed against the upper surface of the polishing pad 2 and held by the polishing head 6 while the slurry 4 is supplied between the wafer 5 and the polishing pad 2, and the wafer 5 is relatively slid with respect to the polishing pad 2. Since the polishing material is contained in the slurry 4, the surface of the wafer 5 can be polished.

[0045] In addition, the laser beams are introduced to the respective laser irradiation sections 9 from a laser light source not shown via a transmission path, and the laser beams R are irradiated to the wafer 5 as a polishing target from the front end side of the laser irradiation sections 9 as shown in FIG. 6. The laser beams R are transmitted through the pouch 7 and the wafer 5, and the region where the laser beams R are focused is irradiated to the upper surface of the slurry 4 and the polishing pad 2. Figure 2

[0046] Since the infrared light (IR light) is used as the laser beams R, the pouch 7 and the wafer 5 can not be heated, and the slurry 4 and the polishing pad 2 can be mainly heated, and the temperature of the polishing surface of the wafer 5 can be adjusted to the target polishing temperature. For example, the polishing surface of the wafer 5 and the slurry 4 adjacent to the polishing surface can be heated to the target temperature of 40°C to 70°C.

[0047] By heating the polishing surface of the wafer 5 to the target temperature, the chemical reaction between the slurry 4 and the polishing surface of the wafer 5 during polishing is promoted, and the polishing rate is improved. In addition, by relatively moving the laser irradiation sections 9 in the rotational direction with respect to the wafer 5 as a polishing target during polishing, the region irradiated with the laser beams R can be relatively moved with respect to the wafer 5, and thus a local temperature difference can be prevented.

[0048] Figure 4 The frequency dependence of the extinction coefficient K of silicon (Si) and water (H2O) is shown.

[0049] As shown in FIG. 5, silicon shows high transparency in the infrared region (IR region), and in contrast, water has an absorption wavelength with respect to light near a wavelength of 3 μm (3000 nm) and near a wavelength of 6 μm (6000 nm). In addition, the absorption rate of water gradually increases with respect to light exceeding a wavelength of 10 μm (10000 nm), and shows a relatively high absorption wavelength at a wavelength of 15 μm (15000 nm). Figure 4 Therefore, as described above, it is desirable that the laser beams emitted from the laser irradiation sections 9 are selected from the range of 2.5 μm or more to 3.5 μm or less, or the range of 5.5 μm or more to 6.5 μm or less, or the wavelength of 10 μm or more (IR light).

[0050]

[0051] is a graph showing the frequency dependence of the extinction coefficient K of silicon (Si) and water (H2O). Figure 5 Figure 2 ​​A schematic diagram illustrating the temperature distribution in the case where the plurality of laser irradiation sections 9 irradiate the slurry 4 or the polishing pad 2 with laser beams, and the surface 5a of the wafer 5 is heated.

[0052] In Figure 5 , for example, the power of the laser beam RA irradiated to the center portion in the surface 5a of the wafer 5 is set to be the lowest, and the power of the laser beam RB irradiated to the outer side of the center portion and the outermost periphery is set to be the largest. Further, the power of the laser beam RC irradiated to the region between the outer side of the center portion and the outermost periphery is set to be intermediate. As described above, since the laser power can be used separately, all the laser irradiation sections 9 can individually control the power. By setting the laser power as described above, the laser power can be adjusted in a manner that uniform heating with high in-plane uniformity is achieved on the surface (polishing surface) 5a.

[0053] In addition, the central region where the laser beams from the laser irradiation sections 9 are condensed in a dot shape is a region heated to the highest temperature, and the quasi-heating regions where the heating temperature is sequentially lower are sequentially generated in a concentric circle shape around the high-temperature heating region. For example, in Figure 5 , in the region RA heated by the laser beam irradiated to the center portion, the center portion RA1 thereof becomes a region heated to the highest temperature, RA2 is a region of the 2nd highest temperature, and RA3 is a region of the 3rd highest temperature. In addition, in the region RB heated by the laser beam irradiated to the outermost periphery, the center portion RB1 thereof becomes a region heated to the highest temperature, RB2 is a region of the 2nd highest temperature, and RB3 is a region of the 3rd highest temperature.

[0054] Further, in Figure 5 , outside the regions of the 3rd highest temperature RA3 and RB3, although not particularly described, the regions outside thereof also become regions heated to a temperature slightly lower than the regions of the 3rd highest temperature RA3 and RB3.

[0055] Since the plurality of laser irradiation sections 9 are densely arranged as shown in Figure 3 , the quasi-heating regions based on the adjacent laser irradiation sections 9 overlap each other or are close to each other, whereby uniform heating with high in-plane uniformity can be achieved on the surface (polishing surface) 5a of the wafer 5.

[0056] Further, in order to further improve the heating temperature uniformity of the wafer surface, a mechanism that swings the polishing head 6 is additionally provided to the wafer 5, and it is preferable that the polishing head 6 be configured to be able to relatively swing with respect to the wafer 5.

[0057] The semiconductor manufacturing apparatus A according to the first embodiment can rapidly heat the surface (polishing surface) 5a of the wafer 5 without affecting the inflow or concentration of the slurry. In addition, by individually controlling the power or irradiation time of each laser irradiation section 9, it is possible to control the temperature distribution in the wafer 5 surface during polishing. In addition, by relatively oscillating the laser irradiation section 9 with respect to the wafer 5 as the polishing target, it is possible to prevent the generation of a localized temperature difference. As a result, it is possible to improve the in-plane uniformity of the polishing characteristics, such as improving the uniformity of the polishing rate or eliminating the step difference after polishing.

[0058] The laser irradiation section 9 can achieve individual power control, and can also control the irradiation time, so it is possible to achieve localized in-plane temperature control in the surface of the wafer 5, and it is also possible to improve the temperature responsiveness during heating.

[0059] Furthermore, in the configuration of the present embodiment, the polishing head 6 is rotated by providing a not-illustrated moving mechanism that relatively moves in the rotation direction with respect to the wafer 5 as the polishing target. However, a configuration can also be adopted in which the moving mechanism is omitted, the moving direction is not limited to the rotation direction, and the surface (polishing surface) 5a of the wafer 5 is polished only by the relative sliding of the polishing pad 2 and the wafer 5.

[0060] "Second Embodiment"

[0061] Figure 6 A semiconductor manufacturing apparatus (polishing apparatus) B according to the second embodiment is shown. The semiconductor manufacturing apparatus B according to the second embodiment has the following feature in addition to the same configuration as the semiconductor manufacturing apparatus A according to the first embodiment, that is, a cooling mechanism 11 is provided above the polishing pad 2.

[0062] The semiconductor manufacturing apparatus B has the stage 1, the polishing pad 2, the slurry nozzle 3, the slurry 4, the polishing head 6, the bag 7, the retaining ring 8, and the laser irradiation section 9, and also has the cooling mechanism 11.

[0063] The cooling mechanism 11, for example, includes a three-dimensional shaped tank that can accommodate a cooling liquid such as water, and a mechanism can be adopted in which the cooling mechanism 11 approaches the polishing pad 2 from above after coming into contact with the liquid surface of the slurry 4 or the upper surface of the polishing pad 2 to rob heat from the polishing pad 2 to cool the polishing pad 2. As the cooling mechanism 11, a cooling slider or the like that comes into contact with the slurry 4 or the polishing pad 2 can be adopted. It is desirable to form a configuration in which a pipe for circulating the cooling liquid is connected to the cooling mechanism 11 to circulate the cooling liquid.

[0064] The semiconductor manufacturing apparatus B of the second embodiment can obtain the same effects as the semiconductor manufacturing apparatus A of the first embodiment described above, and can directly cool the slurry 4 or the polishing pad 2 by providing the cooling mechanism 11. The slurry 4 cooled by the cooling mechanism 11 is rotated in contact with any of the wafers 5 and the polishing pad 2, so the wafer 5 can be indirectly cooled by the cooling mechanism 11 via the slurry 4 or the polishing pad 2.

[0065] The semiconductor manufacturing apparatus B of the second embodiment can heat the wafer 5 by the plurality of laser irradiation sections 9 and cool the wafer 5 by the cooling mechanism 11, so the configuration in which the heating device for the wafer 5 and the cooling device for the wafer 5 are provided separately is obtained. By adopting the temperature and cooling separation configuration in which the heating device and the cooling device for the wafer 5 are provided separately, the thermal responsiveness in the case of polishing the wafer 5 can be improved. In addition, if the thermal responsiveness of the heating and cooling of the wafer 5 is improved, in the case of polishing the wafer 5, the reactivity of the slurry 4 can be controlled in detail, the in-plane uniformity of the polishing characteristics can be improved, for example, the uniformity of the polishing rate or the removal of the step difference after polishing can be improved.

[0066] "Third Embodiment"

[0067] Figure 7 A semiconductor manufacturing apparatus (polishing apparatus) C of the third embodiment is shown. The semiconductor manufacturing apparatus C of the third embodiment has the same configuration as the semiconductor manufacturing apparatus A of the first embodiment, and has the following feature, that is, the cooling mechanism 11 is provided above the polishing pad 2.

[0068] The semiconductor manufacturing apparatus B has the stage 1, the polishing pad 2, the slurry nozzle 3, the slurry 4, the polishing head 6, the bag 7, the holding ring 8, and the laser irradiation section 9, and has the cooling mechanism 11.

[0069] The cooling mechanism 11 has, for example, a three-dimensional shaped tank 11A that can accommodate a cooling liquid such as water, and a plurality of jet nozzles 11B formed on the lower surface of the tank 11A. The cooling mechanism 11 can adopt a mechanism in which the cooling liquid 12 such as water is supplied from the plurality of jet nozzles 11B to the upper surface of the polishing pad 2 to take heat from the polishing pad 2, and the polishing pad 2 is cooled. It is desirable that a configuration in which the cooling liquid is supplied is obtained by forming the cooling mechanism 11 to which a pipe for supplying the cooling liquid is connected.

[0070] The semiconductor manufacturing apparatus C of the third embodiment can achieve the same operating effect as the semiconductor manufacturing apparatus A of the first embodiment described above, and the slurry 4 or the polishing pad 2 can be directly cooled by providing a cooling mechanism 11 with a jet nozzle 11B. Since the slurry 4 cooled by the cooling mechanism 11 rotates with the polishing pad 2 and comes into contact with any one of the wafers 5, the wafers 5 can be indirectly cooled by the cooling mechanism 11 via the slurry 4 or the polishing pad 2.

[0071] The semiconductor manufacturing apparatus C of the third embodiment can heat the wafer 5 using multiple laser irradiation units 9 and cool the wafer 5 using a cooling mechanism 11, thus having a structure in which the heating device and the cooling device of the wafer 5 are separately provided. By adopting such a temperature and cold separation structure that separates the heating device and the cooling device of the wafer 5, the thermal responsiveness during the polishing of the wafer 5 can be improved. In addition, if the thermal responsiveness of the heating and cooling of the wafer 5 is improved, the reactivity of the slurry 4 can be controlled in detail during the polishing of the wafer 5, and the in-plane uniformity of the polishing characteristics can be improved, such as improving the uniformity of the polishing rate or eliminating the step difference after polishing.

[0072] "The structure of the object being ground"

[0073] Figure 8 A schematic cross-section of the grinding object 13, which is the grinding object of the semiconductor manufacturing apparatus (grinding apparatus) A, B, and C in the first to third embodiments described above.

[0074] On a semiconductor substrate SW, such as a silicon wafer, on which components (not shown in the figure) are formed, an insulating film 14, including a silicon oxide film, is formed, for example, with a thickness of 150 nm. Within the insulating film 14, a plurality of wiring grooves 15 with rectangular cross-sections are formed to a depth of 100 nm.

[0075] A barrier film 16 comprising tantalum (Ta) with a thickness of 10 nm is formed by partially filling the wiring trough 15 and covering the insulating film 14 around the wiring trough 15. In addition, a wiring metal film 17 comprising copper (Cu) with a thickness of 500 nm is formed by filling the wiring trough 15 and covering the upper surface side of the barrier film 16.

[0076] also, Figure 8 The grinding object 13 shown is actually a thin circular plate, capable of grinding with... Figure 1 The wafer 5 shown is similarly mounted on the upper surface of the polishing pad 2. When applied to... Figure 1 When the semiconductor manufacturing apparatus A shown is being ground, it can be configured to... Figure 8 The upper surface of the wiring metal film 17 shown serves as the grinding surface of the grinding object 13, and the grinding surface is in contact with the upper surface of the grinding pad 2.

[0077] "First Manufacturing Method for Semiconductor Devices"

[0078] right Figure 8 The object to be ground, 13 shown, for example, is used... Figure 1 The semiconductor manufacturing apparatus (grinding apparatus) A shown irradiates a laser beam R from a laser irradiation unit 9 at a surface temperature of 65°C immediately after the grinding process begins. The surface temperature is detected by an infrared monitor (not shown) and the power of the laser beam R is adjusted accordingly. To ensure uniform temperature within the wafer surface, it is preferable to reduce the power of the laser beam R irradiating the central portion of the wafer, where the temperature tends to rise, compared to the peripheral portion.

[0079] Next, the power of the laser beam R is adjusted while grinding is performed to maintain the temperature of the grinding surface at 65°C until the thickness of the wiring metal film 17 becomes 100nm.

[0080] Heat is generated by the friction between the wafer 5 and the polishing pad 2. Therefore, in order to maintain the temperature of the polishing surface at 65°C, the power of the laser beam R must be gradually reduced. During the irradiation of the laser beam R, by moving the laser irradiation part 9 relative to the polishing object 13 in the rotational direction, localized temperature differences can be prevented.

[0081] Next, if the eddy current monitor (not shown) or similar device detects that the thickness of the wiring metal film 17 has reached 100 nm, then the irradiation of the laser beam R is stopped, and the grinding continues until the wiring metal film 17 on the barrier film 16 disappears (see reference). Figure 9 Stopping the laser beam R is to prevent the wiring metal film 17 in the wiring trough 15 from dishing, and to prevent the high-density wiring area from being eroded by the dipping.

[0082] Next, use with Figure 1 Another semiconductor manufacturing apparatus (polishing apparatus) with the same structure (not shown) partially removes the barrier film 16, wiring metal film 17, and insulating film 14 by polishing. Polishing is performed until the wiring height reaches 50 nm, electrically separating the wiring between adjacent wiring slots, thereby forming a semiconductor device 20 with wiring structure 18 (see reference). Figure 10 ).

[0083] In the manufacturing method of the semiconductor device 20 described above, the grinding surface of the workpiece 13 can be rapidly heated using the laser irradiation unit 9 without affecting the flow or concentration of the slurry. Furthermore, by individually controlling the power or irradiation time of each laser irradiation unit 9, temperature distribution within the grinding surface can be controlled during the grinding process. Moreover, by moving the laser irradiation unit 9 relative to the workpiece 13 (or wafer 5), localized temperature differences can be prevented.

[0084] As a result, in-plane uniformity of polishing properties, such as uniformity of polishing rate or elimination of step difference after polishing, can be improved, and generation of residues of the wiring metal film 17 on the barrier film 16, generation of dishing and erosion due to excessive polishing in local areas in the plane can be prevented.

[0085] "Second manufacturing method of semiconductor device"

[0086] The polishing target in the second manufacturing method is the same as the polishing target 13 used in the first manufacturing method. In this embodiment, the semiconductor manufacturing device (polishing device) B of the second embodiment shown in FIG. 6 is used. Figure 6 The laser beam R is irradiated from the laser irradiation section 9 so that the polishing surface temperature becomes 65°C from the start of polishing in the semiconductor manufacturing device (polishing device) B of the second embodiment shown in FIG. 6. At the same time, the slurry 4 and the polishing pad 2 are cooled on the downstream side of the polishing surface using the cooling mechanism 11.

[0087] Next, polishing is performed so that the temperature of the polishing surface is maintained at 65°C until the thickness of the wiring metal film 17 becomes 100 nm. Next, after the thickness of the wiring metal film 17 is detected to have reached 100 nm, the irradiation of the laser beam R is stopped, and polishing is performed until the wiring metal film 17 on the barrier film 16 disappears while the polishing surface temperature is 40°C by cooling using the cooling mechanism 11.

[0088] Next, the barrier film 16 and the wiring metal film 17, the insulating film 14 are partially removed by another semiconductor manufacturing device (polishing device) of the same configuration as that of the first embodiment shown in FIG. 3 to form the wiring structure 18 shown in FIG. 5, and the semiconductor device 20 is formed. Figure 2 Figure 9 Figure 10

[0089] In the manufacturing method of the semiconductor device 20 described above, the inhomogeneity of the temperature distribution on the polishing pad 2 due to heat generated by friction or chemical reactions during polishing can be eliminated. Furthermore, the temperature distribution in the polishing surface can be controlled to be more uniform than in the first manufacturing method described above. In addition, compared to the first manufacturing method, generation of residues of the wiring metal film 17 on the barrier film 16, generation of dishing and erosion due to excessive polishing in local areas in the plane can be prevented.

[0090] [Explanation of symbols]

[0091] A semiconductor manufacturing device (polishing device)

[0092] R laser beam

[0093] 1 stage

[0094] 2 polishing pad

[0095] ​​​3 slurry nozzle

[0096] 4 slurry

[0097] 5 wafer (semiconductor substrate)

[0098] 6 polishing head

[0099] 7 pocket

[0100] 8 holding ring

[0101] 9 laser irradiation section

[0102] 13 polishing object

[0103] SW semiconductor substrate

[0104] 15 wiring groove

[0105] 16 potential barrier film

[0106] 17 wiring metal film

[0107] 18 wiring structure

[0108] 20 semiconductor device

Claims

1. A semiconductor manufacturing apparatus comprising: a polishing head that holds a polishing object having a first surface and a second surface, the first surface being a surface to be polished, the second surface being opposite to the first surface, the polishing head having a lower surface facing the second surface, the lower surface having a central portion and a peripheral portion, and the polishing head having a plurality of laser irradiation units assembled in the polishing head in a region from the central portion to the peripheral portion, and at least one of the plurality of laser irradiation units irradiating a laser beam to the second surface of the polishing object.

2. The semiconductor manufacturing apparatus according to claim 1, wherein the polishing object is a semiconductor substrate, the at least one of the plurality of laser irradiation units irradiates a laser beam having a wavelength identical to a transmission wavelength of the polishing object.

3. The semiconductor manufacturing apparatus according to claim 1, wherein the at least one of the plurality of laser irradiation units irradiates a laser beam having a wavelength in an infrared wavelength range.

4. The semiconductor manufacturing apparatus according to claim 1, wherein the at least one of the plurality of laser irradiation units irradiates a laser beam of at least one of light having a wavelength of 2.5 μm or more and 3.5 μm or less, light having a wavelength of 5.5 μm or more and 6.5 μm or less, and light having a wavelength of 10 μm or more.

5. The semiconductor manufacturing apparatus according to claim 1, wherein the at least one of the plurality of laser irradiation units includes one of a YAG laser, a YSGG laser, a ZBLAN laser, a YLF laser, and a CO2 laser.

6. The semiconductor manufacturing apparatus according to claim 1, wherein an emission power of each of the at least one of the plurality of laser irradiation units is individually controllable.

7. The semiconductor manufacturing apparatus according to claim 1, further comprising: a polishing pad that polishes the first surface of the polishing object, and a cooling mechanism that cools the polishing pad.

8. The semiconductor manufacturing apparatus according to claim 1, further comprising: a bag of a film through which the laser beam is transmitted, the bag being provided in the polishing head, and the bag is inflatable by injection of a fluid to pressurize the polishing object.

9. The semiconductor manufacturing apparatus according to claim 8, wherein the film is composed of silicone rubber that does not contain silica particles.

10. The semiconductor manufacturing apparatus according to claim 1, further comprising: a moving mechanism that moves the plurality of laser irradiation units relative to the polishing object.

11. A method of manufacturing a semiconductor device using the semiconductor manufacturing apparatus according to claim 1, the method comprising: polishing the first surface of the polishing object held by the polishing head, and causing the at least one of the plurality of laser irradiation units to irradiate the laser beam to the second surface of the polishing object.

12. The method of manufacturing a semiconductor device according to claim 11, wherein the polishing object is a semiconductor substrate, a wavelength of the laser beam is within a transmission wavelength of the polishing object.

13. The method for manufacturing a semiconductor device according to claim 11, wherein the power of the laser beam is varied in the polishing.

14. The method for manufacturing a semiconductor device according to claim 11, further comprising: cooling a polishing pad that polishes the first surface of the polishing object using a cooling mechanism while the at least one of the plurality of laser beam irradiation units irradiates the laser beam to the second surface of the polishing object.

15. The method for manufacturing a semiconductor device according to claim 11, further comprising: moving the at least one of the plurality of laser beam irradiation units relative to the polishing object using a moving mechanism while the polishing head polishes the first surface of the polishing object.

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