Substrate processing method and substrate processing system

Abstract

The present invention provides a substrate processing method and a substrate processing system. Appropriately wet etching the substrate improves the in-plane uniformity of the substrate thickness. The substrate processing method is used to process a substrate, and the substrate processing method includes: a process of grinding one side of the substrate; a process of measuring the thickness of the substrate; a process of wet etching the one side; and a process of wet etching the other side of the substrate after flipping the substrate, during the wet etching process of the one side, the in-plane thickness of the substrate is made uniform based on the measurement result of the thickness, and during the wet etching process of the other side, the thickness of the substrate is reduced to a target thickness.

Description

Technical Field

[0001] The invention relates to a substrate processing method and a substrate processing system. Background Art

[0002] Patent Document 1 discloses an etching method for slicing a silicon single crystal ingot to obtain a wafer. In this etching method, a plurality of etching liquid supply nozzles are provided, and the etching amount within the wafer surface is controlled by changing the flow rate of the etching liquid supplied to the central portion and the peripheral portion of the upper surface of the wafer, thereby efficiently making the upper surface of the wafer highly flat.

[0003] Patent Document 1: International Publication No. 2007 / 088755 Summary of the invention

[0004] Problem that the invention aims to solve

[0005] The technology of the present invention appropriately performs wet etching on a substrate and improves the in-plane uniformity of the substrate thickness.

[0006] Solutions for solving problems

[0007] A technical solution of the present invention is a substrate processing method for processing a substrate, the substrate processing method comprising: a process of grinding one side of the substrate; a process of measuring the thickness of the substrate; a process of wet etching the one side; and a process of wet etching the other side of the substrate after flipping the substrate, during the wet etching process of the one side, the in-plane thickness of the substrate is made consistent based on the measurement result of the thickness, and during the wet etching process of the other side, the thickness of the substrate is reduced to a target thickness.

[0008] Effects of the Invention

[0009] According to the present invention, wet etching of a substrate can be appropriately performed, and the in-plane uniformity of the substrate thickness can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 FIG. 1 is a plan view schematically showing an example of the structure of a wafer processing system.

[0011] Figure 2 FIG. 1 is a side view schematically showing an example of the structure of a wafer processing system.

[0012] Figure 3 It is a plan view schematically showing an example of the structure of an etching device.

[0013] Figure 4 It is a side view schematically showing an example of the structure of an etching device.

[0014] Figure 5 It is a side view showing an example of the structure of the holding member.

[0015] Figure 6 This is a flowchart showing an example of main steps of wafer processing.

[0016] Figure 7 This is an explanatory diagram showing an example of main steps of wafer processing. DETAILED DESCRIPTION

[0017] In the manufacturing process of semiconductor devices, the following processing is usually performed: a wafer as a substrate obtained by cutting and slicing an ingot is formed into a device, and various processing is performed on the formed device wafer. In addition, in order to properly process the device wafer, a process is performed to flatten the surface of the wafer. There are various methods for flattening the surface of the wafer, for example, as disclosed in Patent Document 1, there is a method of supplying an etching solution to the upper surface of the wafer.

[0018] However, even when the upper surface of the wafer is flattened, the thickness of the wafer may be uneven within the surface, and the wafer cannot be properly processed. Patent Document 1 describes flattening the upper surface of a wafer obtained from an ingot, but does not describe improving the uniformity of the thickness within the surface. This viewpoint has room for improvement.

[0019] The technology of the present invention appropriately performs wet etching on a substrate and appropriately improves the in-plane uniformity of the substrate thickness. Hereinafter, a wafer processing system as a substrate processing system and a wafer processing method as a substrate processing method according to the present embodiment for improving the in-plane uniformity of the substrate thickness are described with reference to the accompanying drawings. In addition, in this specification and the accompanying drawings, elements having substantially the same functional structure are marked with the same reference numerals and repeated descriptions are omitted.

[0020] First, the configuration of a wafer processing system according to this embodiment will be described.

[0021] In the wafer processing system 1 of the present embodiment, a process for improving the in-plane uniformity of thickness is performed on the wafer W obtained by cutting from the ingot as described above. Hereinafter, the cut surface of the wafer W may be simply referred to as the front surface Wa and the back surface Wb.

[0022] like Figure 1 As shown, the wafer processing system 1 has a structure in which a loading and unloading station 2 and a processing station 3 are connected as one body. The loading and unloading station 2 and the processing station 3 are arranged in a row from the negative direction side of the X-axis to the positive direction side. The loading and unloading station 2 loads and unloads a box C capable of storing a plurality of wafers W between, for example, the outside. The processing station 3 has various processing devices for performing desired processing on the wafer W.

[0023] The delivery station 2 is provided with a cassette stage 10. In the illustrated example, a plurality of, for example, three cassettes C are freely placed in a row along the Y-axis direction on the cassette stage 10. The number of cassettes C placed on the cassette stage 10 is not limited to the present embodiment and can be arbitrarily determined.

[0024] In the delivery station 2, the wafer conveying area 20 is arranged on the positive direction side of the box mounting table 10 in a manner adjacent to the box mounting table 10. A wafer conveying device 22 that can move freely on a conveying path 21 extending in the Y-axis direction is provided in the wafer conveying area 20. The wafer conveying device 22 has two conveying arms 23, 23 that hold and convey the wafer W. Each conveying arm 23 is configured to move freely in the horizontal direction, in the vertical direction, around the horizontal axis and around the vertical axis. In addition, the structure of the conveying arm 23 is not limited to the present embodiment, and any structure can be adopted. Moreover, the wafer conveying device 22 is configured to be able to convey the wafer W relative to the box C of the box mounting table 10 and the conveying device 30 described later.

[0025] At the carrying in and out station 2, a conveying device 30 and a flipping device 31 are stacked on the positive side of the X-axis of the wafer conveying area 20. The conveying device 30 is adjacent to the wafer conveying area 20 and is used for transferring the wafer W. The flipping device 31 serves as a substrate flipping unit and is used for flipping the front and back sides of the wafer W.

[0026] For example, three processing modules G1 to G3 are provided in the processing station 3. The first processing module G1, the second processing module G2, and the third processing module G3 are arranged in order from the negative direction side of the X axis (the side of the carrying in and out station 2) to the positive direction side.

[0027] The first processing module G1 is provided with an etching device 40 as an etching unit, a cleaning device 41, and a wafer conveying device 50. The etching device 40 is provided in two rows in the X-axis direction and three layers in the vertical direction at a position close to the feeding and unloading station 2 of the first processing module G1. That is, in the present embodiment, six etching devices 40 are provided. The cleaning device 41 is provided in three layers stacked in the vertical direction on the X-axis positive direction side of the etching device 40. The wafer conveying device 50 is arranged on the Y-axis positive direction side of the etching device 40 and the cleaning device 41. The detailed structure of the etching device 40 will be described later. In addition, the number and arrangement of the etching device 40, the cleaning device 41, and the wafer conveying device 50 are not limited thereto.

[0028] The etching device 40 etches the cut surface, i.e., the surface Wa and the back surface Wb of the wafer W. For example, an etching liquid (chemical solution) is supplied to the surface Wa or the back surface Wb to wet-etch the surface Wa or the back surface Wb. For example, HF, HNO3, H3PO4, TMAH, Choline, KOH, etc. are used as the etching liquid.

[0029] The cleaning device 41 cleans the ground surface of the wafer W that has been ground in the processing device 80 described later. For example, the ground surface is brought into contact with a brush and the brush is used to clean the ground surface. In addition, a pressurized cleaning liquid may be used to clean the ground surface. In addition, the cleaning device 41 may also be configured to clean both the front and back surfaces of the wafer W at the same time when cleaning the wafer W.

[0030] The wafer conveying device 50 has two conveying arms 51, 51 for holding and conveying the wafer W. Each conveying arm 51 is configured to be movable in the horizontal direction, in the vertical direction, around the horizontal axis and around the vertical axis. In addition, the structure of the conveying arm 51 is not limited to the present embodiment, and any structure can be adopted. The wafer conveying device 50 is movable on a conveying path 52 extending in the X-axis direction. Moreover, the wafer conveying device 50 is configured to be able to convey the wafer W relative to each processing device of the conveying device 30, the flipping device 31, the first processing module G1 and the second processing module G2.

[0031] The second processing module G2 is provided with a conveyor 60 for delivering the wafer W, a flipping device 61 as a substrate flipping unit for flipping the front and back sides of the wafer W, and a wafer conveying device 70. The conveyor 60 and the flipping device 61 are stacked. The wafer conveying device 70 is arranged on the negative side of the Y axis of the conveyor 60 and the flipping device 61. In addition, the number and arrangement of the conveyor 60, the flipping device 61 and the wafer conveying device 70 are not limited to this.

[0032] The wafer conveying device 70 has two conveying arms 71, 71 for holding and conveying the wafer W. Each conveying arm 71 is configured to be movable in the horizontal direction, in the vertical direction, around the horizontal axis and around the vertical axis. In addition, the structure of the conveying arm 71 is not limited to the present embodiment, and any structure can be adopted. In addition, the number of conveying arms 71 of the wafer conveying device 70 is also not limited to the present embodiment, and any number of conveying arms 71 can be provided, for example, one can be provided. Moreover, it is configured to be able to convey the wafer W relative to each processing device of the first processing module G1 to the third processing module G3.

[0033] The third process module G3 is provided with a processing device 80 as a grinding unit. The processing device 80 includes a rotating table 81, a rough grinding unit 82, and a fine grinding unit 83.

[0034] The rotating table 81 is configured to be rotatable around a vertical rotation center line 84 by a rotating mechanism (not shown). Four chucks 85 for adsorbing and holding the wafer W are provided on the rotating table 81. The chucks 85 are evenly arranged on the same circumference as the rotating table 81, that is, every 90 degrees. The four chucks 85 can be moved to the handover position A0 and the processing positions A1 and A2 by the rotation of the rotating table 81. In addition, the chucks 85 are configured to be rotatable by a rotating mechanism (not shown).

[0035] The handover position A0 is a position on the side of the second processing module G2 (the negative direction side of the X axis and the negative direction side of the Y axis) of the rotating table 81, and is used to hand over the wafer W. A thickness measuring unit 86 for measuring the thickness of the wafer W held on the chuck 85 is arranged at the handover position A0. The first processing position A1 is a position on the positive direction side of the X axis and the negative direction side of the Y axis of the rotating table 81, and the rough grinding unit 82 is arranged at the first processing position A1. The second processing position A2 is a position on the positive direction side of the X axis and the positive direction side of the Y axis of the rotating table 81, and the fine grinding unit 83 is arranged at the second processing position A2.

[0036] The cut surface of the wafer W is roughly ground in the rough grinding unit 82. The rough grinding unit 82 has a first grinding section 82a, which has a rough grinding wheel (not shown) that is annular and rotatable. In addition, the first grinding section 82a is configured to be movable in the vertical direction along the support 82b. In addition, the chuck 85 and the grinding wheel are rotated respectively while the grinding surface of the wafer W held on the chuck 85 is in contact with the grinding wheel, and the cut surface is roughly ground.

[0037] The cut surface of the wafer W is finely ground in the fine grinding unit 83. The fine grinding unit 83 has a second grinding section 83a, which is provided with a fine grinding wheel (not shown) that is annular and rotatable. In addition, the second grinding section 83a is configured to be movable in the vertical direction along the support 83b. In addition, the particle size of the abrasive grains of the fine grinding wheel is smaller than the particle size of the abrasive grains of the rough grinding wheel. Moreover, in a state where the grinding surface of the wafer W held on the chuck 85 is in contact with the grinding wheel, the chuck 85 and the grinding wheel are rotated respectively, and the cut surface is finely ground.

[0038] The thickness measuring unit 86 measures the in-plane distribution of the thickness of the wafer W after the grinding process. The measured in-plane distribution of the thickness is output to the control device 90 described later, and the grinding conditions (such as the tilt of the stage, etc.) of other wafers W to be processed later are feedback controlled. In addition, in the present embodiment, the measured in-plane distribution of the thickness is also used for the optimization of the process and parameters of the wet etching process performed by the etching device 40.

[0039] The above wafer processing system 1 is provided with a control device 90 as a control unit. The control device 90 is, for example, a computer having a CPU, a memory, etc., and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of wafers W of the wafer processing system 1. In addition, the program storage unit also stores a program for controlling the operation of the drive system of the above-mentioned various processing devices, conveying devices, etc. to realize the wafer processing described later of the wafer processing system 1. In addition, the above-mentioned program may be stored in a computer-readable storage medium H, and loaded from the storage medium H to the control device 90.

[0040] Next, the detailed structure of the above-mentioned etching device 40 will be described.

[0041] like Figure 3 As shown, the etching device 40 has a processing container 100, and the interior of the processing container 100 can be sealed. A wafer W delivery port (not shown) is formed on the side of the processing container 100 near the wafer conveying device 50, and an opening and closing gate (not shown) is provided at the delivery port.

[0042] like Figure 3 and Figure 4 As shown in FIG. 1 , a holding mechanism 110 for holding a wafer W is provided inside the processing container 100. The holding mechanism 110 includes a substantially disk-shaped susceptor 111 and a plurality of holding members 112 provided on the outer periphery of the susceptor 111. Figure 5 As shown in FIG. 1 , a concave portion 112 a is formed on the side surface of the holding member 112 to which the outer edge of the wafer W is inserted. Figure 4 As shown, the wafer W is held by a plurality of holding members 112. The holding members 112 are configured to be movable in the horizontal direction by a moving mechanism (not shown).

[0043] A rotation mechanism 113 is provided at the center of the susceptor 111. The rotation mechanism 113 is connected to a rotation drive unit (not shown) and is configured to rotate the susceptor 111 and the wafer W held thereon freely. The rotation mechanism 113 is hollow.

[0044] A cup 120 is provided around the susceptor 111 to collect and recover liquid scattered or dropped from the wafer W. A discharge pipe 121 for discharging the recovered liquid and an exhaust pipe 122 for exhausting the atmosphere in the cup 120 by vacuum suction are connected to the bottom surface of the cup 120 .

[0045] like Figure 3 and Figure 4 As shown, a first arm 130 and a second arm 140 are provided above the base 111 and the cup 120 .

[0046] The first arm 130 is provided with a two-fluid nozzle 131 as a spray nozzle for supplying etching liquid to the wafer W. In addition, the first arm 130 is provided with a moving mechanism 132. Figure 3 and Figure 4 As shown, the first arm 130 is configured to be rotatable in the horizontal direction by the moving mechanism 132 , or is configured to be movable up and down in the vertical direction by the moving mechanism 132 .

[0047] The two-fluid nozzle 131 is connected to an etching liquid supply pipe 133 for supplying etching liquid to the wafer W and a gas supply pipe 134 for supplying gas. The etching liquid from the etching liquid supply pipe 133 and the gas from the gas supply pipe 134 are mixed inside the two-fluid nozzle 131 .

[0048] The etching liquid supply pipe 133 is connected to an etching liquid supply source 135 in which etching liquid is stored. In addition, the etching liquid supply pipe 133 is provided with a valve 133v for controlling the supply of etching liquid.

[0049] The gas supply pipe 134 is connected to a gas supply source 136 in which a gas, for example, an inert gas such as nitrogen, is stored. The gas supply pipe 134 is provided with a valve 134v for controlling the supply of gas.

[0050] The two-fluid nozzle 131 is configured to spray the etching liquid onto the wafer W by controlling the supply amount of the etching liquid and the gas. Moreover, by spraying the etching liquid onto the wafer W in this way, in addition to wet etching the wafer W using the etching liquid, the etching is also performed using the impact force of the etching liquid on the wafer W. That is, wet etching is selectively performed on the portion of the wafer W to which the etching liquid is sprayed. In addition, the etching amount of the wafer W is controlled by the spraying time and the spraying amount of the etching liquid and the gas.

[0051] In addition, the number and arrangement of the two-fluid nozzles 131 are not limited to the illustrated example, and can be arbitrarily selected.

[0052] The second arm 140 is provided with an etching liquid nozzle 141 for supplying etching liquid to the wafer W, a rinsing liquid nozzle 142 for supplying rinsing liquid, and a gas nozzle 143 for supplying gas. In addition, as the etching liquid nozzle 141 and the rinsing liquid nozzle 142, for example, a laminar flow nozzle is used. In addition, the second arm 140 is provided with a moving mechanism 144. Figure 3 and Figure 4 As shown, the second arm 140 is configured to be rotatable in the horizontal direction by the moving mechanism 144 , or is configured to be movable up and down in the vertical direction by the moving mechanism 144 .

[0053] The etching liquid nozzle 141 is connected to an etching liquid supply source 146 via an etching liquid supply pipe 145 for supplying etching liquid to the wafer W. In addition, a valve 145v for controlling the supply of etching liquid is provided in the etching liquid supply pipe 145. In addition, the etching liquid supply source 146 may be common to the etching liquid supply source 135. That is, the etching liquid supply pipe 145 may be connected to the etching liquid supply source 135.

[0054] The etching liquid nozzle 141 supplies the etching liquid to the wafer W in a laminar flow state, thereby uniformly wet-etching the etching surface of the wafer W.

[0055] The rinse liquid nozzle 142 is connected to a rinse liquid supply source 148 via a rinse liquid supply pipe 147 for supplying the rinse liquid to the wafer W. The rinse liquid supply pipe 147 is provided with a valve 147 v for controlling the supply of the rinse liquid.

[0056] The rinse liquid nozzle 142 supplies the rinse liquid to the wafer W after the wet etching, thereby rinsing and cleaning the etched surface.

[0057] The gas nozzle 143 is connected to a gas supply source 150 via a gas supply pipe 149 for supplying a gas, for example, an inert gas such as nitrogen, to the wafer W. In addition, a valve 149v for controlling the gas supply is provided in the gas supply pipe 149. In addition, the gas supply source 150 may be common to the gas supply source 136. That is, the gas supply pipe 149 may be connected to the gas supply source 136.

[0058] The gas nozzle 143 supplies gas to the rinse-cleaned wafer W to dry the etched surface.

[0059] In addition, the number, arrangement, and type of nozzles disposed in the second arm 140 are not limited to the illustrated example, and can be arbitrarily selected.

[0060] A lower surface side nozzle 160 is provided below the susceptor 111 to supply cleaning liquid and rinse liquid to the surface opposite to the etching surface (hereinafter referred to as "lower surface") of the wafer W held by the holding mechanism 110. The lower surface side nozzle 160 is provided to protrude from the hollow rotating mechanism 113.

[0061] The lower surface nozzle 160 is connected to a supply pipe 161 that supplies cleaning liquid to the lower surface of the wafer W. The supply pipe 161 passes through the rotating mechanism 113 and branches into a cleaning liquid supply pipe 162 and a rinse liquid supply pipe 163 on the side opposite to the lower surface nozzle 160 .

[0062] The cleaning liquid supply pipe 162 is connected to a cleaning liquid supply source 164 in which cleaning liquid is stored. For example, FPM (hydrofluoric acid hydrogen peroxide solution aqueous solution), SC2 (hydrochloric acid hydrogen peroxide solution aqueous solution), etc. are used. In addition, the cleaning liquid supply pipe 162 is provided with a valve 162v for controlling the supply of cleaning liquid.

[0063] The cleaning liquid supply pipe 162 supplies cleaning liquid to the adsorption surface (the surface opposite to the grinding surface ground by the processing device 80 ) to wash away particles and the like that are scattered and attached to the adsorption surface during the grinding process of the processing device 80 .

[0064] The rinse liquid supply pipe 163 is connected to a rinse liquid supply source 165 in which a rinse liquid, such as pure water, is stored. In addition, a valve 163v for controlling the supply of the rinse liquid is provided in the rinse liquid supply pipe 163. In addition, a nozzle for supplying the rinse liquid may be provided independently of the lower surface side nozzle 160. In addition, the rinse liquid supply source 165 may be common to the rinse liquid supply source 148. That is, the rinse liquid supply pipe 163 may be connected to the rinse liquid supply source 148.

[0065] The rinse liquid supply pipe 163 supplies the rinse liquid to the adsorption surface cleaned by the cleaning liquid supply pipe 162 , thereby rinsing and cleaning the adsorption surface.

[0066] In the present embodiment, the cleaning liquid and the rinse liquid are supplied from the lower surface side nozzle 160 , but the gas may be supplied by changing either or both of the cleaning liquid and the rinse liquid.

[0067] The supply pipe 161 is provided with a temperature control device 166 for controlling the temperature of the cleaning liquid and the rinsing liquid supplied from the lower surface side nozzle 160. When etching the wafer W using the above-mentioned two-fluid nozzle 131, the temperature of the wafer W may decrease due to the vaporization of the etching liquid, thereby reducing the etching rate. Therefore, the cleaning liquid and the rinsing liquid whose temperature is controlled are supplied from the lower surface side nozzle 160, thereby suppressing the temperature drop of the wafer W during wet etching. That is, the lower surface side nozzle 160 is equivalent to the temperature regulating liquid nozzle of the present invention, and the cleaning liquid and the rinsing liquid are equivalent to the temperature regulating liquid.

[0068] The wafer processing system 1 and the etching apparatus 40 of the present embodiment are configured as described above. Next, wafer processing performed by the wafer processing system 1 and the etching apparatus 40 configured as described above will be described.

[0069] First, a cassette C containing a plurality of wafers W obtained by cutting and slicing an ingot is placed on a cassette placement table 10 of a loading and unloading station 2. In the present embodiment, the upper surface side of the wafers W stored in the cassette C is defined as the front surface Wa, and the lower surface side is defined as the back surface Wb.

[0070] Next, the wafer W in the cassette C is taken out by the wafer conveying device 22 and is conveyed to the conveying device 30 . Next, the wafer W in the conveying device 30 is taken out by the wafer conveying device 50 and is conveyed to the conveying device 60 .

[0071] Next, the wafer W is transported to the processing device 80 by the wafer transport device 70. In the processing device 80, the wafer W is delivered to the chuck 85 at the delivery position A0.

[0072] Next, the rotating table 81 is rotated to move the wafer W to the first processing position A1. Figure 7 As shown in (a), the surface Wa of the wafer W is roughly ground by the rough grinding unit 82 ( Figure 6 Step S1).

[0073] Next, the rotating table 81 is rotated to move the wafer W to the second processing position A2. Figure 7 As shown in (a), the surface Wa of the wafer W is finely ground by the fine grinding unit 83 ( Figure 6 Step S1).

[0074] Next, the rotating table 81 is rotated to move the wafer W to the transfer position A0 .

[0075] Next, the wafer W is transported to the cleaning device 41 by the wafer transport device 70. Figure 7 As shown in (b), the grinding surface of the wafer W, that is, the surface Wa, is scrubbed and cleaned in the cleaning device 41 ( Figure 6 In addition, in the cleaning device 41, the back surface Wb of the wafer W may be cleaned together with the front surface Wa.

[0076] Next, the wafer W is transported to the reversing device 61 by the wafer transport device 70. The wafer W is reversed in the reversing device 61. That is, the wafer W is reversed upside down so that the ground surface Wa becomes the lower surface and the back surface Wb becomes the upper surface.

[0077] Next, the wafer W with the front and back sides turned over is transported to the processing device 80 again by the wafer transport device 70. Then, the rotating table 81 is rotated to move the wafer W to the first processing position A1 and the second processing position A2 in sequence. Figure 7 As shown in (c), the back side Wb of the wafer W is subjected to rough grinding and fine grinding ( Figure 6 Step S3).

[0078] Next, the rotating table 81 is rotated to move the wafer W to the transfer position A0 .

[0079] like Figure 7 As shown in (d), for a wafer W whose surface Wa and back Wb have been ground, the thickness distribution ( Figure 6When measuring the thickness distribution, the chuck 85 (wafer W) is rotated, and the thickness measuring unit 86 is horizontally moved in the radial direction above the wafer W, thereby obtaining the thickness distribution in units of radial positions.

[0080] In addition, the thickness distribution acquired by the thickness measuring unit 86 is used to perform feedback control on processing conditions (for example, the tilt of the stage) of the next wafer W to be processed by the wafer processing system 1 .

[0081] Next, the wafer W is transported to the cleaning device 41 by the wafer transport device 70. In the cleaning device 41, as shown in FIG. Figure 7 As shown in (e), the back surface Wb of the wafer W that has been ground is scrubbed and cleaned ( Figure 6 In addition, in the cleaning device 41, the surface Wa and the back surface Wb of the wafer W may be cleaned together.

[0082] Next, the wafer W is transported to the etching device 40 by the wafer transport device 70. In the etching device 40, as shown in FIG. Figure 7 As shown in (f), the back side Wb of the wafer W, which is one side of the present embodiment, is wet-etched using an etching solution ( Figure 6 Step S6).

[0083] When wet etching is performed on the back surface Wb, the two-fluid nozzle 131 provided on the first arm 130 is horizontally moved in the radial direction while the wafer W is rotated by the rotating mechanism 113, thereby selectively wet etching any position on the back surface Wb of the wafer W. In addition, grinding marks formed by the grinding process of the processing device 80 on the back surface Wb of the wafer W can be removed, and the in-plane thickness of the wafer W can be made uniform. In addition, after the etching process of the back surface Wb of the wafer W, the thickness of the wafer W is greater than the target thickness.

[0084] Here, the wet etching of the back side Wb is based on the thickness distribution of the wafer W measured in step S4, so that the in-plane thickness of the wafer W is uniform, and the process and parameters of the wet etching are optimized. Specifically, in the thickness distribution of the wafer W, the etching amount is increased at the radial position where the thickness of the wafer W is judged to be larger, and the etching amount is reduced at the radial position where the thickness of the wafer W is judged to be smaller. The etching amount of the wafer W is controlled by, for example, the injection time and injection amount of the etching liquid injected from the two-fluid nozzle 131. That is, when the two-fluid nozzle 131 moves horizontally in the radial direction, the moving speed of the two-fluid nozzle 131 and the injection amount of the etching liquid are controlled corresponding to the relative position of the two-fluid nozzle 131 relative to the wafer W.

[0085] Thus, in the present embodiment, a spray nozzle (two-fluid nozzle 131) is used as a nozzle for supplying etching liquid, and the etching liquid is sprayed to the etching target area in the surface of the wafer W. Thus, as described above, in addition to the wet etching by supplying the etching liquid, etching is performed by utilizing the pressure (impact force) when the etching liquid impacts any etching target area in the surface of the wafer W. That is, compared with wet etching by supplying liquid from a laminar flow nozzle, the etching target area can be selectively processed.

[0086] Furthermore, when wet etching is performed on the back surface Wb of the wafer W, a cleaning liquid or a rinse liquid may be supplied from the lower surface side nozzle 160 to the lower surface (surface Wa) of the wafer W, thereby simultaneously cleaning the surface Wa.

[0087] In addition, when etching is performed by spraying the etching liquid from the two-fluid nozzle 131, as described above, the temperature of the wafer W decreases due to the vaporization heat generated by vaporization of the etching liquid sprayed onto the wafer W, which may reduce the etching rate. Therefore, in order to suppress the reduction in the etching rate, it is desirable to control the temperature of the cleaning liquid and the rinse liquid supplied from the lower surface side nozzle 160 to the surface Wa of the wafer W by the temperature control device 166, thereby suppressing the temperature reduction of the wafer W.

[0088] When the etching process of the back surface Wb is completed, the first arm 130 is retracted from above the wafer W, and the second arm 140 is moved above the wafer W.

[0089] Next, while the wafer W is rotated, the valve 147 v is controlled to supply the rinse liquid from the rinse liquid nozzle 142. In this way, the back surface Wb of the wafer W after the wet etching is rinsed and cleaned.

[0090] When the cleaning of the back surface Wb is completed, the valves 147v and 149v are controlled to stop the supply of the rinse liquid from the rinse liquid nozzle 142 and supply the gas from the gas nozzle 143. In this way, the back surface Wb of the wafer W after rinsing and cleaning is dried.

[0091] When the back surface Wb is dried, the wafer W is transported to the reversing device 31 by the wafer transport device 50. The front and back surfaces of the wafer W are reversed in the reversing device 31. That is, the wafer W is reversed upside down so that the unetched surface Wa becomes the upper surface and the etched back surface Wb becomes the lower surface.

[0092] Next, the wafer W with the front and back sides turned over is transported to the etching device 40 again by the wafer transport device 50. In the etching device 40, as shown in FIG. Figure 7 As shown in (g), the surface Wa of the wafer W, which is the other surface of the present embodiment, is wet-etched using an etching liquid ( Figure 6 Step S7).

[0093] When wet etching the surface Wa, the etching liquid is supplied in a laminar flow from the etching liquid nozzle 141 provided on the second arm 140 while the wafer W is rotated by the rotating mechanism 113. Moreover, the etching liquid spreads due to the centrifugal force, thereby wet etching the entire surface Wa of the wafer W. Thus, the grinding marks formed by the grinding process of the processing device 80 can be removed, and the surface Wa of the wafer W can be uniformly etched. In addition, thereby, the wafer W is thinned to the desired target thickness.

[0094] Here, in the wet etching of the surface Wa, for example, the position of the etching liquid nozzle 141, the supply amount of the etching liquid, the supply time of the etching liquid, the number of rotations of the wafer W, etc. are controlled. Thus, the etching amount can be made uniform in the surface of the wafer W. In addition, according to the present embodiment, since the thickness of the wafer W is controlled to be uniform in the wet etching of the back side Wb, the in-plane thickness of the wafer W can be easily controlled.

[0095] Next, when the etching process of the surface Wa is completed, the valves 145v and 147v are controlled to stop the supply of the etching liquid from the etching liquid nozzle 141 while the wafer W is rotated, and the rinsing liquid is supplied from the rinsing liquid nozzle 142. In this way, the surface Wa of the wafer W is rinsed and cleaned. At this time, the rinsing liquid may be supplied from the lower surface side nozzle 160, so that the back side Wb of the wafer W is rinsed and cleaned at the same time.

[0096] When the cleaning of the surface Wa is completed, the valves 147v and 149v are controlled to stop the supply of the rinse liquid from the rinse liquid nozzle 142 and supply the gas from the gas nozzle 143. In this way, the surface Wa of the wafer W after rinsing and cleaning is dried.

[0097] After that, the wafer W that has been subjected to all the processing is transported to the conveyor 30 by the wafer transport device 50, and then transported to the cassette C of the cassette stage 10 by the wafer transport device 22. In this way, a series of wafer processing of the wafer processing system 1 is completed. In addition, the cassette C that carries the wafer W in may be different from the cassette C that carries the wafer W out.

[0098] According to the above embodiment, based on the in-plane thickness distribution of the wafer W measured by the thickness measuring unit 86, the process and parameters of the wet etching are optimized for each processed wafer W, so that the in-plane uniformity of the thickness of the wafer W can be appropriately improved. In addition, after one side of the wafer W is flattened by wet etching, the other side is wet etched, so that the etching amount of the other side can be easily made uniform in the plane. That is, the in-plane uniformity of the thickness can be appropriately improved.

[0099] Furthermore, since the variation in the in-plane thickness of the wafer W can be reduced in this manner, the load on the subsequent step, ie, wafer processing (eg, a step of polishing the wafer W) can be reduced.

[0100] Furthermore, according to the present embodiment, a spray nozzle is used in wet etching of one side in order to make the thickness of the wafer W uniform, and etching is performed using the impact force of the etching liquid on the wafer W. Thus, the diffusion of the etching liquid when landing on the wafer W can be suppressed, and etching can be appropriately performed at a desired position in the surface of the wafer W. That is, the in-plane uniformity of the wafer W can be more appropriately improved.

[0101] Furthermore, by performing wet etching using a spray nozzle, the consumption of etching liquid can be reduced compared to the case where wet etching is performed using a conventional laminar flow nozzle.

[0102] In addition, when the etching liquid is supplied to one side of the wafer W using the spray nozzle, the temperature of the wafer W decreases due to the vaporization of the supplied etching liquid, which may deteriorate the etching rate. However, according to the present embodiment, a cleaning liquid or a rinse liquid is supplied as a temperature regulating liquid to the other side of the wafer W, thereby suppressing the temperature drop of the wafer W and appropriately suppressing the deterioration of the etching rate.

[0103] In addition, in the above embodiment, the thickness measuring unit 86 is provided at the intersection position A0 of the processing device 80, but the number and arrangement of the thickness measuring unit 86 are not limited to the above embodiment. For example, the thickness measuring unit 86 may be provided outside the processing device 80, and another thickness measuring unit (not shown) for optimizing the wet etching process may be further provided. Figure 1 The thickness measuring unit 86 is arranged at a position between the transfer position A0 and the processing position A2 of the processing apparatus 80 shown as a measurement position A3.

[0104] In addition, in the above-mentioned embodiment, after the two-fluid nozzle 131 wet-etches the back surface Wb, the rinse liquid is supplied from the rinse liquid nozzle 142 to perform rinse liquid cleaning, but the back surface Wb may be further etched by the etching liquid nozzle 141 before the rinse liquid cleaning. More specifically, after the back surface Wb is selectively etched by the spray nozzle, the laminar flow nozzle may be used to etch in a manner that evenly flattens the entire back surface Wb. In this way, the in-plane uniformity of the thickness of the wafer W can be more effectively improved.

[0105] In addition, in the above-mentioned embodiment, the rough grinding unit 82 and the fine grinding unit 83 are respectively provided at the two processing positions A1 and A2 provided in the processing device 80, but the structure of the processing device 80 is not limited thereto. For example, a surface grinding unit for grinding the surface Wa of the wafer W may be provided at the processing position A1, and a back grinding unit for grinding the back surface Wb of the wafer W may be provided at the processing position A2. In this case, the surface grinding unit and the back grinding unit provided at the processing position A1 and the processing position A2 correspond to the first grinding section and the second grinding section of the present invention, respectively.

[0106] In the above embodiment, the wet etching is performed on the front and back surfaces of the wafer W obtained by directly cutting and slicing the ingot. However, the wafer W as the substrate processed by the wafer processing system 1 is not limited to this.

[0107] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The above embodiments may be omitted, replaced, or modified in various forms without departing from the scope of the claims and the gist thereof.

Claims

1. A substrate processing method, which is used to process a substrate, wherein: The substrate processing method comprises: A step of grinding one side of the substrate; The process of measuring the thickness of the substrate; A step of wet etching the one side; and After the substrate is turned over, the other side of the substrate is wet-etched. During the wet etching process of the one side, the in-plane thickness of the substrate is made uniform based on the measured in-plane distribution of the thickness, During the wet etching process of the other surface, the thickness of the substrate is reduced to a target thickness.

2. The substrate processing method according to claim 1, wherein: The substrate processing method includes a step of grinding the other surface of the substrate.

3. The substrate processing method according to claim 1 or 2, wherein: The wet etching of the one surface is performed using an etching liquid sprayed from a spray nozzle toward the substrate.

4. The substrate processing method according to claim 3, wherein: The etching amount of the one surface is controlled by the spraying time and the spraying amount of the etching liquid from the spray nozzle.

5. The substrate processing method according to claim 1 or 2, wherein: During the wet etching process of the one surface, a temperature regulating liquid for regulating the temperature of the one surface to a constant level is simultaneously supplied to the other surface.

6. The substrate processing method according to claim 1 or 2, wherein: The thickness of the substrate on the one side after wet etching is greater than the target thickness.

7. The substrate processing method according to claim 1 or 2, wherein: The wet etching of the other surface is performed using an etching liquid supplied to the substrate from a laminar flow nozzle.

8. The substrate processing method according to claim 1 or 2, wherein: The grinding of the one side and the measurement of the thickness are performed in the same device.

9. The substrate processing method according to claim 1 or 2, wherein: Based on the measurement result of the thickness of one substrate, the grinding conditions of the next substrate are feedback-controlled.

10. A substrate processing system for processing a substrate, wherein: The substrate processing system has: a grinding part for grinding one side of the substrate; a thickness measuring unit for measuring the thickness of the substrate; an etching unit, which performs wet etching on the substrate; a substrate reversing unit for reversing the front and back sides of the substrate; and a control unit that at least controls the operation of the etching unit, The control unit controls the operation of the etching unit to perform the following processing: Based on the measured in-plane distribution of the thickness, wet etching is performed on the one side to make the in-plane thickness of the substrate uniform, After the substrate is turned over, the other side of the substrate is wet-etched to reduce the thickness of the substrate to a target thickness.

11. The substrate processing system according to claim 10, wherein: The grinding section grinds the other surface of the substrate.

12. The substrate processing system according to claim 10 or 11, wherein: The etching unit includes a spray nozzle that sprays an etching liquid onto one surface of the substrate.

13. The substrate processing system according to claim 12, wherein: The control unit controls the spraying time and the spraying amount of the etching liquid to the one surface.

14. The substrate processing system according to claim 10 or 11, wherein: The control unit controls the operation of the etching unit so that the thickness of the substrate after wet etching on the one side is greater than the target thickness.

15. The substrate processing system according to claim 10 or 11, wherein: The etching part comprises: an etching liquid nozzle for supplying etching liquid to the other side of the substrate; a rinse liquid nozzle for supplying a rinse liquid to the other surface of the substrate; and The gas nozzle supplies gas to the other surface of the substrate.

16. The substrate processing system according to claim 15, wherein: The etching liquid nozzle and the rinsing liquid nozzle are laminar flow nozzles.

17. The substrate processing system according to claim 10 or 11, wherein: The etching unit includes a temperature regulating liquid nozzle for supplying a temperature regulating liquid to the other surface when etching the one surface. The control unit controls the operation of the etching unit so that the temperature of the substrate is maintained constant using the temperature regulating liquid.

18. The substrate processing system according to claim 10 or 11, wherein: The grinding section and the thickness measuring section are arranged in the same device.

19. The substrate processing system according to claim 10 or 11, wherein: The control unit feeds back the measurement result of the thickness measuring unit of one substrate to the grinding condition of the grinding unit of the next substrate.

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