JP2011020100A - Liquid treatment apparatus and liquid treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the deterioration of the yield of a product by detecting whether a treating liquid is present on a substrate or not with a simple structure. <P>SOLUTION: Static sensors 54A-54C are embedded in a spin chuck 2. The capacitance of the static sensor 54, when the treating liquid is present on a wafer W being the substrate, is made larger than that when the treating liquid is absent on the wafer W. It is detected whether the treating liquid is present or not on the wafer W on the spin chuck 2 by the static sensors 54A-54C. As a result, because abnormality of the discharge of the treating liquid from a treating liquid nozzle 4 or the diffusion of the treating liquid on the substrate is smoothly detected by detecting whether the treating liquid is present or not on the wafer W in a prescribed timing, the abnormality is immediately coped with and the deterioration of the yield of the product is suppressed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid processing apparatus and a liquid processing method for supplying a processing liquid from a processing nozzle to a substrate held by a substrate holder.

  There is a step of forming a protective film made of a resist film or a polyimide film. These processes include, for example, a spin chuck configured to be rotatable about a vertical axis, and a processing liquid nozzle for supplying a processing liquid to the surface of a substrate, for example, a semiconductor wafer (hereinafter referred to as “wafer”) W held on the spin chuck. And a liquid processing apparatus equipped with In this apparatus, the processing liquid is supplied from the processing liquid nozzle to the wafer W on the spin chuck, and then the spin chuck is rotated to diffuse the processing liquid on the wafer W by the centrifugal force of rotation. A liquid film of the treatment liquid is formed on the entire surface.

  By the way, in the processing liquid supply system from the tank for storing the processing liquid to the processing liquid nozzle, the processing liquid may not be discharged from the processing liquid nozzle at a predetermined timing because of a valve failure or the like. In addition, since a predetermined amount of the processing liquid is not supplied, there is a case where the diffusion of the processing liquid on the surface of the wafer W is insufficient. If these abnormalities occur, the product will be defective and must be detected promptly.

  On the other hand, in the coating process of resist film and polyimide film, the amount of processing liquid discharged from the processing liquid nozzle is very small, and the heat type flow meter adds heat to the processing liquid and cannot be used. It is difficult to detect. In addition, a nozzle unit in which a large number of nozzle parts are combined may be used as the processing liquid nozzle. However, in the configuration in which a flow meter is provided in the processing liquid supply line, it is necessary to provide a flow meter for each supply line. It becomes complicated. Furthermore, it is preferable to simplify the supply line without providing equipment as much as possible in order to suppress the generation of bubbles and particles.

  On the other hand, with regard to the inspection of the discharge state of the processing liquid from the processing liquid nozzle and the diffusion state of the processing liquid on the surface of the wafer W, for example, Patent Document 1 discloses a method of measuring the amount of laser reflected light on the wafer surface using a laser sensor. Proposed. This technique utilizes the fact that the amount of reflected light becomes zero when the resist solution blocks the laser beam, and the reflectance of the laser beam increases when the resist solution on the wafer W is stretched. Specifically, the difference between the amount of light received when the laser sensor is OFF and the amount of reflected laser light before the resist solution is discharged is defined as a noise margin. Then, the difference between the laser reflected light amount B before the resist solution is discharged and the reflected light amount C during the resist solution discharge is compared with the noise margin, and the difference between the reflected light amount B and the reflected light amount C is smaller. Is judged to be normal when the difference is larger.

  In this method, the threshold value of the noise margin is determined according to the type of processing liquid, so that accurate detection can be performed regardless of the type and characteristics of the processing liquid. Further, by changing the portion irradiated with the laser light, it is possible to detect the discharge state of the processing liquid in the central region of the wafer W and the diffusion state of the processing liquid in the peripheral region of the wafer W. However, if it is attempted to detect the state of the processing liquid at a plurality of locations on the surface of the wafer W, it is necessary to provide a laser sensor and a reflecting plate for each detection portion.

JP 2007-258658 (paragraphs 0055 to 0061, paragraphs 0065 to 0067, etc.)

  The present invention has been made in order to solve such problems, and in performing liquid processing on a substrate by supplying a processing liquid from a processing liquid nozzle to the surface of the substrate held by the substrate holding unit, An object of the present invention is to provide a liquid processing apparatus and a liquid processing method capable of detecting a problem in supplying a processing liquid.

The liquid processing apparatus of the present invention is a liquid processing apparatus that forms a liquid film of a processing liquid on the surface of a substrate.
A substrate holder for sucking and holding the substrate;
A processing liquid nozzle for supplying a processing liquid to the surface of the substrate held by the substrate holding unit;
A detection unit provided in the substrate holding unit for detecting the presence or absence of a processing liquid on the surface of the substrate as a change in capacity;
And an alarm generation unit that generates an alarm based on an output signal of the detection unit.

  Here, the substrate holding part is configured to be rotatable about a vertical axis, and the processing liquid nozzle is configured to discharge the processing liquid to the central part of the substrate, and the processing liquid is moved from the central part to the outer edge by the centrifugal force of the substrate. Can be spread.

  The detection unit may be provided at the center of the substrate holding unit, or a plurality of detection units may be provided so that the distances from the center of the substrate holding unit are different from each other.

  Further, when a predetermined time has elapsed after the command signal for discharging the processing liquid from the processing liquid nozzle is output, the processing liquid exists on the substrate based on the signal corresponding to the output of the detection unit. You may make it provide the control part which judges whether or not. An electrostatic sensor can be used as the detection unit.

The liquid processing method of the present invention is a liquid processing method for forming a liquid film of a processing liquid on the surface of a substrate by supplying the processing liquid from the processing liquid nozzle to the surface of the substrate sucked and held by the substrate holding unit.
Outputting a command signal for discharging the processing liquid from the processing liquid nozzle;
Corresponds to the output of the detection unit provided in the substrate holding unit to detect the presence or absence of processing liquid on the surface of the substrate as a change in capacity when a predetermined time has elapsed since the command signal was output A step of determining whether a processing liquid exists on the substrate based on a signal to be performed; and
Generating an alarm based on an output signal of the detection unit.

At this time, the substrate holding portion for sucking and holding the substrate is rotated about a vertical axis, and the processing liquid is discharged to the central portion of the substrate on the substrate holding portion by the processing liquid nozzle, so that the processing liquid on the substrate is discharged. Is spread from the center to the outer edge by the centrifugal force of the substrate,
When a predetermined first time has passed since the command signal was output, processing is performed on the substrate based on a signal corresponding to the output of the detection unit provided at the center of the substrate holding unit. Determining whether liquid is present; and
Corresponds to the output of the detection unit provided outside the central portion of the substrate holding unit when a second time longer than a predetermined first time has elapsed since the command signal was output And a step of determining whether or not the processing liquid is present on the substrate based on the signal to be performed.

  According to the present invention, since the detection unit that detects the presence or absence of the processing liquid on the surface of the substrate as a change in capacity is provided in the substrate holding unit, it is detected whether or not the processing liquid exists on the surface of the substrate. be able to. Accordingly, it is possible to detect a problem in the supply of the processing liquid.

It is a longitudinal cross-sectional view which shows the liquid processing apparatus which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows the spin chuck used for the said liquid processing apparatus. It is a top view of the spin chuck. It is a block diagram which shows the divider | distributor provided in the said spin chuck. It is a block diagram which shows the oscillation circuit, transmitting antenna, and receiving part which were provided in the said spin chuck. It is sectional drawing for demonstrating the effect | action of embodiment of this invention. It is a flowchart for demonstrating the effect | action of embodiment of this invention. It is process drawing for demonstrating the effect | action of embodiment of this invention. It is the perspective view and side view which show the board | substrate holding part of other embodiment of this invention. It is a top view which shows the board | substrate holding part of other embodiment of this invention. It is a top view which shows embodiment of the application | coating and developing apparatus to which the said coating device is applied. It is a perspective view of the said coating and developing apparatus. It is a longitudinal cross-sectional view of the said application | coating and developing apparatus.

  An embodiment of the liquid processing apparatus 1 according to the present invention will be described. As shown in FIG. 1, a liquid processing apparatus 1 holds a substrate, for example, a wafer W horizontally from the back side in a processing vessel 10 and is configured to be rotatable about a vertical axis (vacuum chuck). ). The spin chuck 2 forms a substrate holding unit for sucking and holding the wafer W. The spin chuck 2 has a substantially disk-like table 21 that holds the wafer W horizontally, and a rotary shaft connected to the center of the lower surface of the table 21. 22.

  For example, as shown in FIG. 2, a drive mechanism 23 is connected to the lower side of the rotary shaft 22 so as to support the rotary shaft 22 so as to be rotatable about a vertical axis and freely movable up and down. Further, the inner lower end side of the rotating shaft 22 is rotatably fitted inside the cylindrical body 24 fixed to the bottom portion of the processing container 10 via a shaft portion 25 having a sealing function. The shaft portion 25 includes a bearing portion (not shown) and a magnetic seal, and hermetically seals between the rotating shaft 22 and the cylindrical body 24. The spin chuck 2 is connected to a vacuum pump 27 in order to suck the wafer W from the back side through a suction path 26 formed in the inner region of the rotating shaft 22 and the cylindrical body 24 and a suction tube 27a. ing. The internal structure of the table 21 will be described later.

  Returning to FIG. 1, a processing cup 3 is provided around the spin chuck 2. The processing cup 3 includes an inner cup 31 disposed so as to face the peripheral edge of the back surface of the wafer W sucked and held on the spin chuck 2, and surrounds the inner cup 31 from the side and the lower side. The intermediate cup 32 is provided, and the outer cup 33 is disposed above the intermediate cup 32.

  The intermediate cup 32 is provided with a liquid receiving part 34, and one end side of a liquid draining path 35 is connected to the lower surface of the liquid receiving part 34 for discharging the processing liquid, and flows down from the peripheral part of the wafer W. A processing liquid or the like is guided to the drainage path 35 through the inner cup 31. In addition, two exhaust paths 36 are connected to the liquid receiving portion 34 in order to exhaust the atmosphere in the processing container 10. The outer cup 33 is provided so as to cover the atmosphere on the upper side of the wafer W of the spin chuck 2 in the circumferential direction in order to reduce disturbance of the airflow around the wafer W when it rotates.

  Further, a processing liquid nozzle 4 is provided in the processing container 10 in order to supply a processing liquid to the surface of the wafer W held by the spin chuck 2. The nozzle 4 discharges the processing liquid to the center of the wafer W when a liquid film of the processing liquid is formed on the surface of the wafer W as will be described later. For this reason, the arm (not shown) is configured to be movable and raised and lowered between a discharge position for discharging the processing liquid to the center of the wafer W and a standby position outside the cup 3. Further, a supply source 42 of, for example, a polyimide solution, which is a processing liquid, is connected to the processing liquid nozzle 4 via a processing liquid supply pipe 41 having a flow rate adjusting unit (not shown).

  Further, a fan filter unit (FFU) 37 for supplying clean gas to the inside of the processing container 10 is connected to the processing container 10, and an exhaust pipe 38 is connected to the bottom surface. Thus, a downdraft is formed in the processing container 10. In FIG. 1, reference numeral 11 denotes a transfer port for carrying the wafer W into and out of the processing container 10, and reference numeral 12 denotes a shutter for opening and closing the transfer port 11.

  Next, the table 21 will be described in detail with reference to FIGS. The table 21 is configured to suck and hold a wafer W having an outer diameter of, for example, 300 mm from the back surface side, and is formed so that, for example, the planar shape is substantially the same as that of the wafer W. The center portion of the table 21 is configured to be aligned with the center portion of the wafer W placed on the table 21. A convex portion 51A is formed at the center of the upper surface of the table 21, and, for example, arc-shaped convex portions 51B and 51C are formed along a concentric circle at a position half the radius of the table 21 and at the outer edge. Has been. The upper surfaces of these three convex portions 51A to 51C form a substrate holding surface for holding the wafer W by suction, and are formed to have the same height so that the wafer W can be held horizontally. In this example, the arc-shaped convex portions 51B and 51C along the concentric circles are arranged in two radial directions in order to simplify the explanation, but may be three or more.

  A suction hole 52 is opened between the convex portion 51A and the convex portion 51B, and the suction hole 52 is formed in the rotary shaft 22 through a suction path 53 formed in the table 21. It communicates with the path 26. When the wafer W is placed on the table 21 and the atmosphere on the back surface side of the wafer W is sucked from the suction hole 52 through the suction path 26, the table 21 and the back surface of the wafer W are shown in FIG. The atmosphere between them flows from the outer peripheral side toward the inner peripheral suction hole 52 through the gap between the convex portions 51 </ b> B, and the wafer W is sucked and held on the table 21.

  The table 21 is made of, for example, a resin such as PEEK (polyetheretherketone), PBI (polybenzimidazole), PP (polypropylene), or PTFE (polytetrafluoroethylene), in this example, PEEK.

  For example, one electrostatic sensor 54A to 54C is embedded in the vicinity of the surface of the three convex portions 51A to 51C in the table 21 for each convex portion 51A to 51C. When the wafer W is sucked and held by the table 21 in this way, an electrostatic sensor 54A (hereinafter referred to as “first electrostatic sensor 54A”) is provided below the center of the wafer W, and is half the radius of the wafer W. An electrostatic sensor 54B (hereinafter referred to as “second electrostatic sensor 54B”) is provided below the position, and an electrostatic sensor 54C (hereinafter referred to as “third electrostatic sensor 54C”) is provided below the outer edge of the wafer W. Will be established). These electrostatic sensors 54A to 54C form a detection unit for detecting the presence or absence of the processing liquid on the surface of the wafer W as a change in capacitance, and are configured to output a voltage signal of capacitance.

  A power supply line storage pipe 55 is provided on the central axis of the rotary shaft 22, and a power supply line is wired therein. The lower end of the pipe 55 is connected to an upper member 56 a that forms part of the connecting unit 56. In the connecting unit 56, the upper member 56a and the lower member 56b are coupled so as to be rotatable about a vertical axis, and the upper member 56a and the lower member 56b are electrically connected to each other. The lower member 56b is fixed to the cylindrical body 24, and the inside of the lower member 56b is connected to a power supply unit 57 via a power cable 57a. Thus, the power cable 57a and the power line in the pipe 55 are electrically connected.

  In the figure, reference numeral 6 denotes a power supply distributor. For example, as shown in FIG. 4, a power supply voltage is supplied to each of the electrostatic sensors 54 </ b> A to 54 </ b> C via the distributor 6. Reference numeral 61 denotes a power cable for supplying power to the electrostatic sensor 54A. Although the power cables 62 and 63 are wired from the distributor 6 to the other electrostatic sensors 54B and 54C, they are omitted in FIG. 1 to avoid complication of the drawing.

  The electrostatic sensors 54A to 54C are connected to oscillation circuits 71A to 71C provided in the rotary shaft 22 via signal lines 64A to 64C. In FIG. 2, for convenience of illustration, only the one corresponding to the electrostatic sensor 54A is drawn. Transmitting antennas 72A to 72C are arranged in the circumferential direction of the rotating shaft 22, and are configured to transmit the oscillation outputs from the oscillation circuits 71A to 71C in a non-contact manner to receiving units 8A to 8C described later. The transmitting antennas 72A to 72C and the receiving units 8A to 8C are provided for the electrostatic sensors 54A to 54C as shown in FIG. The oscillation circuits 71A to 71C are configured such that the oscillation level changes according to voltage signals from the signal lines 64A to 64C, for example.

  As shown in FIG. 5, the receiving units 8A to 8C have a receiving antenna 81 that receives the oscillation output from the transmitting antennas 72A to 72C, and a band that passes the frequency band of the oscillation output of the oscillation circuits 71A to 71C. A pass filter 82, a rectifier circuit 83 that rectifies the frequency signal sent from the filter 82, and a binarization processing unit 84 that binarizes the rectified output using a threshold value are provided.

  Here, in the electrostatic sensors 54A to 54C, when there is liquid on the wafer W, the capacitance increases and the voltage signal changes (increases), and thus the oscillation output levels in the oscillation circuits 71A to 71C change. (Increased) and rectified output changes. Therefore, the binarization processing unit 84 has a rectified output level corresponding to the voltage signal output from the electrostatic sensors 54A to 54C when there is no processing liquid on the wafer W, and when there is processing liquid on the wafer W. A threshold value is set in the middle of the rectified output level corresponding to the voltage signal output from the electrostatic sensors 54A to 54C, so that the processing liquid L is placed on the wafer W as shown in FIG. An ON signal is output at a certain time, and an OFF signal is output when there is no processing liquid L on the wafer W, as shown in FIG. This threshold is obtained in advance by experiments.

  As shown in FIG. 5, the rotating shaft 22 is provided with oscillation circuits 71B and 71C to which signal lines 64B and 64C of the remaining two electrostatic sensors 54B and 54C are connected, and transmitting antennas 72B and 72C. It has been. The set of the oscillation circuit 71B and the transmission antenna 72B and the set of the oscillation circuit 71C and the transmission antenna 72C are provided in the same manner as the set of the oscillation circuit 71A and the transmission antenna 72A, respectively, with different heights. ing. Similarly to the receiving unit 8A, receiving units 8B and 8C are provided at corresponding height positions of the transmitting antennas 72B and 72C. The control unit 9 is configured to transmit a binarized signal, that is, an on signal (for example, logic “1”) and an off signal (for example, logic “0”) from the receiving units 8A to 8C.

  The control unit 9 performs overall control of the operation of each device in the liquid processing apparatus 1, and is composed of, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program in which an instruction is set so that a liquid film forming process of the processing liquid described in the operation described later is performed, and the control unit 9 reads the program to the control unit 9 to It controls the rotation speed of the wafer, the supply of processing liquid to the wafer, and the like. The program is stored in the program storage unit while being stored in a storage medium such as a hard disk, a compact disk, a magnetic optical disk, or a memory card.

  Further, the control unit 9 includes a processing liquid detection program 91. The program 91 outputs an electrostatic sensor output when a predetermined time has elapsed since a command signal (hereinafter referred to as “start signal”) for discharging the processing liquid from the processing liquid nozzle 4 is output. It is means for determining whether or not processing liquid exists on the wafer W based on the corresponding signal. The start signal is output by the control unit 9.

  In the processing liquid detection program 91, it is determined whether or not the processing liquid exists on the wafer W as follows. First, according to the process, when the start signal is output and the output from each of the receiving units 8A to 8C is an OFF signal after a predetermined time has elapsed, a step is set so as to determine that the supply of the processing liquid is abnormal. It is rare. The predetermined time is, for example, from when the start signal is output in advance until the processing liquid passes above the first electrostatic sensor 54A, the second electrostatic sensor 54B, and the third electrostatic sensor 54C. Each time is obtained, and these times are given a little margin. For example, assuming that the measurement time from when the start signal is output until the processing liquid reaches the upper position of the second electrostatic sensor 54B is 1 second (a provisional time), for example, 2 is provided with a margin. If the signal is off after 2 seconds, it is determined that the supply is abnormal.

  The following description will be made with these set times corresponding to the first electrostatic sensor 54A to the third electrostatic sensor 54C as times T1, T2, and T3, respectively. First, if the signal C1 from the receiving unit 8A based on the output of the electrostatic sensor 54A is on-signal when the time T1 has elapsed since the start signal was output, the processing liquid is placed above the electrostatic sensor 54A. If it is determined that there is an off signal, it is determined that the processing liquid does not exist above the electrostatic sensor 54A.

  Here, since the first electrostatic sensor 54A is embedded at a position where the processing liquid is discharged from the processing liquid nozzle 4 onto the wafer W, the processing liquid is normally discharged from the processing liquid nozzle 4 onto the wafer W. Then, the signal C1 from the receiving unit 8A based on the output of the electrostatic sensor 54A becomes an ON signal. Therefore, if the output (signal C1) from the receiving unit 8A is an off signal when the first time T1 has elapsed from the start signal, it is determined that the processing liquid from the processing liquid nozzle 4 is abnormally discharged.

  Similarly, the signal C2 from the receiving unit 8B (8C) based on the output of the electrostatic sensor 54B (54C) when the second time T2 (third time T3) has elapsed since the start signal was output. If (C3) is an ON signal, it is determined that the processing liquid exists above the electrostatic sensor 54B (54C). If it is an OFF signal, the processing liquid does not exist above the electrostatic sensor 54B (54C). Judge. Therefore, if the output from the receiving unit 8B (8C) is an off signal when the time T2 (time 3) has elapsed from the start signal, it is determined that the processing liquid is abnormally diffused.

  When the control unit 9 determines that there is an abnormality in the discharge or diffusion of the processing liquid based on the determination information on whether or not the processing liquid exists on the wafer W from the processing liquid detection program 91. For example, a rotation stop signal is output to the drive mechanism 23 and an alarm signal is output to the alarm generation unit 92. The alarm generation unit 92 plays a role of generating a warning sound, lighting a warning lamp, displaying an alarm on a display unit, and the like.

  Next, the operation of the above-described embodiment will be described with reference to FIGS. 7 and 8 by taking as an example the case where a liquid film of a polyimide solution as a processing liquid is formed on the surface of the wafer W. First, the wafer W is loaded into the processing container 10 from the transfer port 11 by an external transfer means, and is transferred to the spin chuck 2 raised to the upper side of the processing cup 3. Then, the wafer W is vacuum-sucked by the spin chuck 2 and lowered to a predetermined position in the processing cup 3. On the other hand, the conveying means is retracted and the shutter 12 is closed.

  Subsequently, the processing liquid nozzle 4 is moved to a position where the processing liquid is supplied to the central portion of the wafer W. Then, a command signal (start signal) for discharging the polyimide solution as the processing liquid from the processing liquid nozzle 4 is output from the control unit 9 (step S1), and the processing liquid is directed toward the surface of the wafer W based on the command signal. Start dispensing. On the other hand, after the start signal is output by the processing liquid detection program 91 of the control unit 9, the capacitance data obtained by the electrostatic sensors 54 </ b> A to 54 </ b> C are always acquired.

  Here, as described above, each of the electrostatic sensors 54A to 54C outputs a voltage signal of capacitance. This capacitance is larger when the processing liquid L is present on the wafer W than when it is not present, so that when the processing liquid L is present on the wafer W, the output at the receiving unit 8 is switched from the off signal to the on signal. .

  When the first time T1 has elapsed since the start signal was output (step S2), it is determined whether or not the signal C1 corresponding to the output of the first electrostatic sensor 54A is an ON signal ( Step S3, FIG. 8 (a)). If the signal C1 is an off signal, it is abnormal, so the rotation of the spin chuck 2 is stopped (step S11), and a predetermined alarm is generated (step S12). On the other hand, if the signal C1 is an ON signal, it is normal, and therefore a command signal is output to the drive mechanism 23 so as to rotate the spin chuck 4 at a low speed, for example, about 1500 rpm to 2000 rpm (step S4). By rotating the spin chuck 4 at a low speed in this way, the processing liquid L on the wafer W is slightly expanded from the center portion toward the outer edge portion by the centrifugal force of rotation. Here, the degree of expansion is such that the processing liquid L exists above the second electrostatic sensor 54B when the second time T2 has elapsed since the start signal was output. Here, the second time T2 is longer than the first time T1.

  Subsequently, when the second time T2 has elapsed since the start signal was output (step S5), it is determined whether or not the signal C2 corresponding to the output of the second electrostatic sensor 54B is an ON signal. (Step S6, FIG. 8B). If the signal C2 is an off signal, it is abnormal, so the rotation of the spin chuck 2 is stopped (step S11), and a predetermined alarm is generated (step S12). On the other hand, if the signal C2 is an ON signal, it is normal, and therefore a command signal is output to the drive mechanism 23 so as to rotate the spin chuck 4 at a high speed, for example, about 2000 rpm to 3000 rpm (step S7). By rotating the spin chuck 4 at a high speed in this way, the processing liquid L on the wafer W is diffused throughout the wafer W by the rotational centrifugal force.

  Next, when the third time T3 has elapsed since the start signal was output (step S8), it is determined whether or not the signal C3 corresponding to the output of the second electrostatic sensor 54C is an ON signal ( Step S9, FIG. 8 (c)). Here, the third time T3 is longer than the second time T2. If the signal C3 is an off signal, it is abnormal, so the rotation of the spin chuck 2 is stopped (step S11), and a predetermined alarm is generated (step S12). On the other hand, if the signal C3 is an ON signal, it is normal and the processing is continued (step S10). For example, the processing liquid nozzle 4 is retracted to a predetermined standby position, and then the wafer W is rotated for a predetermined time to make the film thickness of the polyimide solution liquid film uniform, and the polyimide solution is dried to form a polyimide film. To do. Next, a back rinse may be performed by discharging a solvent, for example, thinner, which is a solution (cleaning solution) to the peripheral portion of the wafer W using a bevel cleaning nozzle (not shown). After the polyimide film is thus formed on the surface of the wafer W, the wafer W is unloaded from the liquid processing apparatus 1 in the reverse order of loading.

According to the above-described embodiment, the electrostatic sensors 54A to 54C are embedded in the spin chuck 2, and the change in capacitance between when the processing liquid is not present on the wafer and when it is present is utilized. It is determined whether or not processing liquid exists on the wafer. As a result, it is possible to detect a problem in supplying the processing liquid from the processing liquid nozzle 4. That is, it is possible to detect an abnormal discharge of the processing liquid from the processing liquid nozzle 4 on the basis of the output of the first electrostatic sensor 54A embedded in the center of the spin chuck 2, which is half the radius of the spin chuck 2. Based on the outputs from the second and third electrostatic sensors 54B and 52C embedded in the position and the outer edge, respectively, the diffusion abnormality of the processing liquid supplied onto the wafer W can be detected.

  Therefore, when a problem occurs in the supply of the treatment liquid, these abnormalities can be detected quickly. When this abnormality is detected, an alarm can be generated immediately, so that the occurrence of a large number of product defects can be suppressed and deterioration of product yield can be prevented.

  In addition, since the presence or absence of the processing liquid on the wafer W is observed by the change in the capacitance of the electrostatic sensors 54A to 54C, the amount of the processing liquid is very small, the bubble generation state, the viscosity, etc. depending on the type of the processing liquid Even when the characteristics are different, the capacitance changes depending on the presence or absence of the processing liquid, so that the presence or absence of the processing liquid on the wafer W can be detected with high accuracy. Furthermore, since the electrostatic sensors 54A to 54C are embedded in the spin chuck 2, the configuration is simpler than when a flow meter is provided for each nozzle.

  In the above, the oscillation circuits 7A to 7C may have a structure (voltage controlled oscillator) in which the oscillation frequency changes according to the voltage of the signal lines 64A to 64C. Measurement is performed by a counter, and an on signal and an off signal are output according to the frequency measurement value.

  As the connecting unit 56, a power line storage pipe 55 is rotatably supported in the cylindrical body 24, and a power coil is provided at the lower end of the cylindrical body 24, while the power coil is also provided on the pipe 55 side. A non-contact type power transfer structure in which a power supply coil is provided so as to be spaced apart and opposed to the lower side and power is transferred between these coils by electromagnetic induction may be employed.

  Furthermore, when a predetermined time has elapsed after the command signal for discharging the processing liquid from the processing liquid nozzle is output, the wafer is based on the signal corresponding to the output of the detection unit (electrostatic sensor 5). The configuration for determining whether or not the processing liquid exists above may be software or a hardware configuration incorporating a logic circuit.

  Furthermore, the method of forming the liquid film of the processing liquid on the substrate is not limited to the above-described configuration, and the substrate is placed on the substrate holding unit and the substrate holding unit is rotated to move from the processing liquid nozzle to the substrate. Alternatively, the processing liquid may be supplied. Also, in the step of rotating the substrate by the substrate holding unit and diffusing the processing liquid on the substrate by the centrifugal force of rotation, the number of rotations of the substrate holding unit may be changed in the middle, or the substrate at the same number of rotations. You may continue rotating a holding | maintenance part.

  Furthermore, the substrate holding part of the present invention is not necessarily configured to be rotatable around the vertical axis, and the processing liquid nozzle side may be moved with respect to the substrate holding part. In this case, the processing liquid nozzle 93 is configured to include discharge holes formed over a length corresponding to the diameter direction of the wafer W, for example, as shown in FIG. Then, the processing liquid nozzle 93 is scanned from the outer side on one end side of the wafer W held by the substrate holding unit 94 toward the outer side on the other end side, whereby a liquid film of the processing liquid L is formed on the wafer W. Form. Examples of the processing solution supplied by such a method include a developing solution and a cleaning solution. The substrate holding portion 94 in this example is configured in the same manner as the above-described spin chuck 2 except that it does not rotate around the vertical axis.

  When the processing liquid is supplied by scanning the processing liquid nozzle 93 as described above, for example, as shown in FIG. 9B, the outer edge portion on one end side and the outer edge portion on the other end side of the substrate holding portion 94 are provided. The electrostatic sensors 95A and 95B are buried in the respective cases. Then, when a predetermined time has elapsed after the command signal for discharging the processing liquid from the processing liquid nozzle 93 is output, the output from the receiving unit corresponding to the output from each of the electrostatic sensors 95A and 95B. Signals C4 and C5 are acquired, and based on these signals C4 and C5, it is determined whether or not processing liquid exists on the wafer W. At this time, the step of generating an alarm based on the static signals C4 and C5 is the same as in the above-described embodiment.

  As described above, in the present invention, it is sufficient that at least one electrostatic sensor is provided in the substrate holding portion. Further, in the substrate holding unit, an electrostatic sensor is provided at a position where the discharge of the processing liquid from the processing liquid nozzle is started, and only detection of whether or not the processing liquid is normally discharged from the processing liquid nozzle is performed. You may do it. Further, in the case where only the detection of the discharge of the processing liquid is performed as described above, the portion (table 21) for sucking and holding the substrate in the substrate holding portion has a planar shape smaller than that of the wafer W. May be. Further, an electrostatic sensor may be provided in the substrate holding unit at a position corresponding to the outer edge of the substrate, and only detection as to whether or not the processing liquid is normally diffused on the substrate surface may be performed. Furthermore, as shown in FIG. 10, a plurality of electrostatic sensors 54B and 54C may be provided on the arc-shaped convex portion 51B and the outer convex portion 51C, respectively. In this case, it is possible to accurately detect the diffusion state of the processing liquid.

  Next, an example in which the above-described liquid processing apparatus is applied to a coating and developing apparatus will be briefly described. In this example, the liquid processing apparatus 1 forms a liquid film of a resist solution that is a processing liquid on the wafer W, and a coating that forms a liquid film of a chemical liquid for an antireflection film that is a processing liquid on the wafer W. Built as a device. FIG. 11 is a plan view of a system in which an exposure apparatus is connected to the coating and developing apparatus, and FIG. 12 is a perspective view of the system. FIG. 13 is a longitudinal sectional view of the system. This apparatus is provided with a carrier block S1, and a transfer arm D1 takes out the wafer W from the hermetically sealed carrier C mounted on the mounting table 101, transfers it to the processing block S2, and transfers from the processing block S2. D1 is configured to receive the processed wafer W and return it to the carrier C.

  As shown in FIG. 11, the processing block S2 is a first block (DEV layer) B1 for performing development processing in this example, and a processing for forming an antireflection film formed on the lower layer side of the resist film. The second block (BCT layer) B2, the third block (COT layer) B3 for applying the resist film, and the fourth block for forming the antireflection film formed on the upper layer side of the resist film (TCT layer) B4 is laminated in order from the bottom.

  The second block (BCT layer) B2 and the fourth block (TCT layer) B4 are each applied by the liquid processing apparatus 1 of the present embodiment that applies a processing liquid for forming an antireflection film by spin coating. Between the coating apparatus 2 and the processing unit group, and a heating / cooling system processing unit group for performing pre-processing and post-processing of the processing performed in the coating apparatus 102. The transfer arms A2 and A4 are configured to transfer the wafer W between them. Here, in the coating apparatus 102, four spin chucks 2 of the above-described embodiment are arranged in the Y direction in the figure. The third block (COT layer) B3 has the same configuration except that the processing solution is a resist solution.

  On the other hand, for the first block (DEV layer) B1, for example, development units are stacked in two stages in one DEV layer B1. In the DEV layer B1, a transfer arm A1 for transferring the wafer W to the two-stage development unit is provided.

  Further, as shown in FIGS. 11 and 13, the processing block S2 is provided with a shelf unit U1, and each part of the shelf unit U1 is accessed by the delivery arm D2 of the processing block S2 and a part of the shelf unit U1. Is configured such that the delivery arm D1 of the carrier block S1 is accessed. Then, the wafer W from the carrier block S1 is successively transferred by the transfer arm D1 to one transfer unit of the shelf unit U1, for example, a transfer unit CPL2 corresponding to the second block (BCT layer) B2. The transfer arm A2 in the second block (BCT layer) B2 receives the wafer W from the transfer unit CPL2 and transfers it to each unit (antireflection film unit and heating / cooling processing unit group). Thus, an antireflection film is formed on the wafer W.

  Thereafter, the wafer W is transferred into the third block (COT layer) B3 via the transfer unit BF2, the transfer arm D2, the transfer unit CPL3 of the shelf unit U1, and the transfer arm A3, thereby forming a resist film. . Further, the wafer W is transferred to the transfer unit CPL11 in the shelf unit U1 through the transfer arm A3 → the transfer unit BF3 of the shelf unit U1 → the transfer arm D2. The wafer W on which the resist film is formed may further have an antireflection film formed in the fourth block (TCT layer) B4. In this case, the wafer W is transferred to the transfer arm A4 via the transfer unit CPL4. After the antireflection film is formed, the wafer W is transferred by the transfer arm A4 to the transfer unit CPL11 via the transfer unit TRS4 and the transfer arm D2. The

  On the other hand, on the upper part in the DEV layer B1, a shuttle arm E which is a dedicated transfer means for directly transferring the wafer W from the transfer unit CPL11 of the shelf unit U1 to the transfer unit CPL12 provided in the shelf unit U2 is provided. ing. The wafer W on which the resist film and further the antireflection film are formed is directly transferred from the transfer unit CPL11 to the transfer unit CPL12 of the shelf unit U2 by the shuttle arm E, and is taken into the interface block S3. In FIG. 12, the delivery unit to which CPL is attached also serves as a cooling unit for temperature control, and the delivery unit to which BF is attached also serves as a buffer unit on which a plurality of wafers W can be placed.

  Next, the wafer W is transferred to the exposure apparatus S4 by the interface arm D3, where a predetermined exposure process is performed, and then placed on the transfer unit TRS6 of the shelf unit U2 and returned to the processing block S2. The returned wafer W is subjected to development processing in the first block (DEV layer) B1, and transferred to the transfer table TRS1 of the shelf unit U1 by the transfer arm A1. Then, it is returned to the original carrier C through the delivery arm D1. In the figure, the shelf unit U3 is provided with a heat system unit group in which a heating unit and a cooling unit are stacked.

  In the above, the processing solution of the present invention includes a polyimide solution, a resist solution, a developing solution, a chemical solution for forming an antireflection film, a chemical solution for forming a protective film, a chemical solution for forming an interlayer insulating film, a cleaning solution, and the like. The liquid processing apparatus can be applied to a coating apparatus, a developing apparatus, an antireflection film forming apparatus, a liquid processing apparatus for forming a protective film, a liquid processing apparatus for forming an interlayer insulating film, a liquid processing apparatus for cleaning processing, etc. .

W Wafer 2 Spin chuck 21 Table 22 Rotating shaft 23 Drive mechanism 27 Vacuum pump 4 Processing liquid nozzles 54A to 54C Electrostatic sensor 9 Control unit 91 Processing liquid detection program

Claims (8)

In a liquid processing apparatus that forms a liquid film of a processing liquid on the surface of a substrate,
A substrate holder for sucking and holding the substrate;
A processing liquid nozzle for supplying a processing liquid to the surface of the substrate held by the substrate holding unit;
A detection unit provided in the substrate holding unit for detecting the presence or absence of a processing liquid on the surface of the substrate as a change in capacity;
The liquid processing apparatus comprising: an alarm generation unit that generates an alarm based on an output signal of the detection unit. The substrate holding part is configured to be rotatable around a vertical axis,
The processing liquid nozzle is configured to discharge the processing liquid to the center of the substrate,
The liquid processing apparatus according to claim 1, wherein the processing liquid spreads from the central portion to the outer edge by a centrifugal force of the substrate.   The liquid processing apparatus according to claim 2, wherein the detection unit is provided at a central portion of the substrate holding unit.   The liquid processing apparatus according to claim 2, wherein a plurality of the detection units are provided such that the distances from the center of the substrate holding unit are different from each other.   Whether a processing liquid exists on the substrate based on a signal corresponding to the output of the detection unit when a predetermined time has elapsed since the command signal for discharging the processing liquid from the processing liquid nozzle is output. The liquid processing apparatus according to claim 1, further comprising a control unit that determines whether or not.   The liquid processing apparatus according to claim 1, wherein the detection unit is an electrostatic sensor. In the liquid processing method of forming a liquid film of the processing liquid on the surface of the substrate by supplying the processing liquid from the processing liquid nozzle to the surface of the substrate sucked and held by the substrate holding unit,
Outputting a command signal for discharging the processing liquid from the processing liquid nozzle;
Corresponds to the output of the detection unit provided in the substrate holding unit to detect the presence or absence of processing liquid on the surface of the substrate as a change in capacity when a predetermined time has elapsed since the command signal was output A step of determining whether a processing liquid exists on the substrate based on a signal to be performed; and
And a step of generating an alarm based on an output signal of the detection unit. The substrate holding portion for sucking and holding the substrate is rotated about a vertical axis, and the processing liquid is discharged to the central portion of the substrate on the substrate holding portion by the processing liquid nozzle, whereby the processing liquid on the substrate is transferred to the substrate. When spreading from the center to the outer edge by the centrifugal force of
When a predetermined first time has passed since the command signal was output, processing is performed on the substrate based on a signal corresponding to the output of the detection unit provided at the center of the substrate holding unit. Determining whether liquid is present; and
Corresponds to the output of the detection unit provided outside the central portion of the substrate holding unit when a second time longer than a predetermined first time has elapsed since the command signal was output The liquid processing method according to claim 7, further comprising a step of determining whether or not a processing liquid exists on the substrate based on a signal to be processed.

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