JP2863925B2 - Processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a processing apparatus used for, for example, exposing and developing a semiconductor wafer.

2. Description of the Related Art When a photoresist film is applied to a semiconductor wafer before an exposure process or when a developing solution is applied to the surface of the semiconductor wafer, a photoresist material or a developing solution is applied to a nozzle placed above the semiconductor wafer. From the surface of the semiconductor wafer. As an example of this, the semiconductor wafer is vacuum-sucked on the chuck and rotated in a semi-fixed state, and the nozzle is linearly moved at a constant speed toward the center of rotation, which is the center of the semiconductor wafer, and is processed in a fixed amount. The liquid is supplied to the semiconductor wafer to apply the processing liquid.

[Problems to be solved by the invention]

By the way, since the semiconductor wafer is rotated at a constant angular velocity, the positions in the wafer at different distances d from the center of rotation will have different distances in the rotational direction at the same time. Therefore, at a position where the distance d is large, a relatively large amount of the processing liquid is required, and at a position where the distance d is small, a relatively small amount of the processing liquid may be used. However, as described above, in the related art, a predetermined amount of the processing liquid is dripped and supplied to the wafer from a nozzle that moves linearly at a constant speed. For this reason, at each position on the wafer at a different distance from the rotation center position, excess or deficiency of the processing liquid occurs, and a portion where the processing liquid is not applied occurs on the surface of the semiconductor wafer, and the processing is performed. There is a disadvantage that uneven application of the liquid occurs. In addition, the viscosity and concentration vary depending on the processing liquid, and in many cases, when the moving speed of the nozzle is constant and the processing liquid amount is constant, the processing liquid cannot be uniformly applied to the surface of the workpiece. SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a processing apparatus in which a portion to which a processing liquid is not applied does not occur on the surface of an object to be processed.

[Means for Solving the Problems]

In the processing apparatus according to the present invention, the processing liquid is supplied onto the processing object while moving the processing liquid supply nozzle in the rotation radial direction above the rotating processing liquid, and the processing liquid is supplied to the processing object. In the processing apparatus for applying, the moving section of the processing liquid supply nozzle is divided into a plurality of sections,
Rotation speed control means for switching and controlling the rotation speed of the object to be processed in each divided movement section in accordance with the radial position of the divided movement section is provided.

[Action]

In the processing apparatus according to the present invention having the above-described configuration, the moving section of the processing liquid supply nozzle is divided into a plurality of sections according to the position of the processing object in the rotation radial direction, and the rotation of the processing object in each of the divided moving sections is performed. The speed is switched and controlled in accordance with the position of the processing liquid supply nozzle in the rotation radial direction. Therefore, the amount of the processing liquid applied to the object to be rotated during rotation becomes appropriate according to each position in the rotation radius direction of the object to be processed, and the processing liquid is uniformly applied over the entire object to be processed. Can be applied.

【Example】

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an example of an electrical configuration in a case where the apparatus according to the present invention is applied to a surface treatment apparatus such as a development processing of a semiconductor wafer. This example is an example in which two semiconductor wafers can be simultaneously processed, and there are two processing systems A and B.
Each system includes unit controllers 11A and 11B, joint boxes 12A and 12B, and processing units 13A and 13B. The processing units 13A and 13B and the unit controllers 11A and 11B each have a microcomputer (hereinafter, referred to as a CPU), and the processing units 13A and 13B perform predetermined processing in response to control commands from the unit controllers 11A and 11B. The processing units 13A and 13B are provided with a chuck for fixing the semiconductor wafer by vacuum suction and for rotating the semiconductor wafer. The rotation speed is set by an instruction from the unit controllers 11A and 11B and is variable. A processing liquid supply nozzle of the unit head is disposed above the chuck. The unit head allows the processing liquid supply nozzle to move on a straight line or a curve passing through the rotation center position of the chuck and the edge of the wafer. The unit head is configured, for example, as shown in FIG. That is, FIG. 2A is a side view of the unit head portion, and FIG. 2B is a plan view. In FIG. 2, reference numeral 31 denotes a nozzle plate to which a nozzle is attached. Reference numeral 32 denotes a sliding body, and the nozzle plate 31 is fixed to the sliding body 32. The sliding body 32 is provided with a through-hole, and the inner peripheral surface of the through-hole is threaded. 33 is a ball screw,
A screw that meshes with a screw on the inner peripheral surface of the through hole of the sliding body 32 is formed on the outer peripheral surface. The ball screw 33 is screwed into a through hole of the sliding body 32. When the ball screw 33 rotates, the sliding body 32 slides along the ball screw 33 in the right or left direction in the figure according to the rotation direction. As a result, the nozzle moves linearly over the semiconductor wafer. 34 is a guide for guiding the sliding movement of the sliding body 32. 35 is a stepping motor. A pulley 37 is attached to the rotating shaft 36 of the ball screw 33, and a timing belt 39 is wound around the pulley 38 attached to the rotating shaft of the stepping motor 35, so that the stepping motor 35
Is transmitted to the rotation shaft of the ball screw 33. By controlling the rotation of the stepping motor 35, the sliding member 32 is controlled.
Of the nozzle, and thus the speed of movement of the nozzle. 40 is a sensor mounting portion, which is a ball screw 33
Is provided along. A plurality of sensors for knowing the position of the sliding body 32, that is, the position of the nozzle, can be mounted on the sensor mounting portion 40 at an arbitrary position.
This sensor detects whether the nozzle moves, for example, at the position where scanning starts, or whether the nozzle comes at the center position of the semiconductor wafer. In FIG. 1, reference numeral 20 denotes a speed controller for controlling the moving speed of the nozzle. This speed controller 20
Has a CPU that is shared by the two systems A and B, and transfers the nozzle moving speed setting data to the unit controller as described later.
The moving speed of the nozzle is controlled by receiving the control commands from the unit controllers 11A and 11B, respectively. 21A and 21B are input panels for setting data such as the moving speed of each nozzle of the system A and the system B. Input data from these input panels 21A and 21B is
The CPU of the speed controller 20 is input to the speed controller 20 via the
Selectively captures input data from 1A or 21B, and the corresponding unit controller 11A or 11B CPU
To the input data. In this speed controller 20, the control of the moving speed of the nozzle is performed by the processing units 13A and 13B of the respective systems A and B.
This is performed by controlling the drive pulse supplied to the stepping motor 35. In this case, the drive control circuit of the motor 35 is constituted by hardware, and the processing unit
It is provided for each of 13A and 13B. Then, output pulses of the drive control circuit are supplied to the stepping motors 35 of the respective systems. FIG. 3 is an example of a drive control circuit of the stepping motor 35, and this circuit is provided for each of the systems A and B. An oscillator 41 generates a pulse having a frequency of 3.072 MHz, for example. The output pulse PI of the oscillator 41 is supplied to a circuit 42 for determining an acceleration when changing the stepping motor 35 from the first speed to the second speed. The acceleration determining circuit 42 includes a first variable frequency dividing circuit 421 and a 1/2 frequency dividing circuit 42.
It consists of two. The first variable frequency dividing circuit 421 is composed of, for example, a counter, and the frequency division ratio can be changed by changing its preset value. The output pulse Pa of the acceleration determination circuit 42 is supplied to a target speed determination circuit 43 of the stepping motor 35. The target speed determination circuit 43 includes a second variable frequency dividing circuit 431,
The second variable frequency dividing circuit 431 is composed of, for example, a counter, and the frequency dividing ratio can be changed by changing its preset value. This target speed determination circuit 43
Is supplied to the stepping motor 35. In this case, the frequency of the output pulse Pa of the acceleration determination circuit 42 is fa, and the frequency of the output pulse Po of the target speed determination circuit 43 is fo.
In this case, the speed of the stepping motor 35 changes at an acceleration determined by the output pulse fa until reaching a speed corresponding to the target frequency fo. As described above, since the frequency division ratio of the first and second variable frequency dividing circuits 421 and 431 can be changed by changing the preset value of the counter, the stepping motor 35 can be changed by appropriately selecting the preset value. Speed can be arbitrarily changed. Here, the N value of the dividing ratio 1 / N of the first variable frequency dividing circuit 421 is
When ACC is set to SPED of the second variable frequency dividing circuit 431, the frequency fo of the output pulse Po is obtained by the following equation. The stepping motor 35 determines the frequency fo of the output pulse Po.
Rotate at a rotation frequency corresponding to. Here, ▼ means a complement of a value obtained by converting setting data (BCD data) on an input panel described later into hexadecimal data. This is because start-up compensation of the stepping motor is performed. In this example, the drive control circuit shown in FIG.
Nozzle moving speed at the time of application of the developing solution,
It is not fixed and can be changed in multiple stages. That is, in this case, one treatment liquid application time, that is, one scan section of the nozzle with respect to the semiconductor wafer is virtually divided into a plurality of sections, and the divided scan sections are supplied to the first and second variable frequency dividing circuits. Preset value
The value is set so that the entire surface of the wafer is uniformly coated, and the moving speed of the nozzle in each divided scan period can be changed to the set speed at the set acceleration. Set the speed and acceleration by using the input panels 21A and 21A.
1B, the overall control during one processing liquid application is performed by the unit controllers 11A and 11B. Hereinafter, the setting operation at the time of one processing liquid application and the processing operation by the unit controllers 11A and 11B performed accordingly will be described. FIG. 4 is an example of the input panel 21A or 21B. In the case of this example, one scan can be divided into three, and therefore, the data setting unit includes three data sets P1, P2, and P3,
Provided. In this example, the data setting items are
Speed data DV and acceleration ACCELERAT for target speed SPEED
Acceleration data DA for ION, split scan time SCAN TI
ME (split scan section), scan delay time SCAN DELAY
TIME, four items. In this example, when the speed data DV is expressed by a three-digit value (decimal system), the speed data DV is from the minimum value [000] to the maximum value [2].
54]. Also, acceleration data DA
Is similarly set from the minimum value [255] to the maximum value [001]. The values ACC and ▲ ▼ in equation (a) above,
The relationship between the acceleration data DA and the speed data DV is as follows. That is, ACC = DA (three-digit decimal number) and ▲ ▼ = 255-DV (three-digit decimal number). The scan delay time is a time from when the speed controller 20 receives a scan start command from the unit controller until the nozzle scan is actually started. This takes into account the delay time when the processing liquid is sent out of the nozzle under pressure. The data setting unit P1 sets data of a divided scan section from the beginning of one scan distance. The data setting unit P2 sets the data of the subsequent divided scan section, and the data setting unit P3 sets the data of the last divided scan section. The data setting method in the data setting section will be described below. Now, for example, as shown in FIG. 5, when a single scan distance is set to 80 mm, this is divided into the first half of the 15 mm divided scan section.
An example is given in which the scanning speed of the nozzle is changed in two stages by dividing the scanning speed into SA and the latter 65 mm divided scanning section SB. In the case of the above example, the data setting unit uses P1 and P2. First, the data setting unit P1 sets the scan time of the divided scan section SA to, for example, 0.5 seconds. The scan delay time is, for example, 0. The scanning direction may be a direction from the peripheral portion of the semiconductor wafer toward the central portion, or may be a direction from the central portion to the peripheral portion. Next, the moving speed S of the nozzle in the divided scan section SA is obtained. Here, S = 15 / 0.5 = 30 mm / sec. Next, the rotational frequency P of the stepping motor 35 is determined from the moving speed S. This is, for example, P = S × 500/27 =
Required as 555.5Hz. Next, based on the rotation frequency of the stepping motor, the appropriate acceleration data DA and speed are obtained from a list of speed data DV and acceleration data DA (which are prepared in advance) as shown in FIG. Obtain the data DV and set it on the input panel. In this case, even if the target speed is the same, it is possible to start up to the target speed with different accelerations by combining the speed data DV and the acceleration data DA. For the divided scan section SB, the scan time, velocity data DV, and acceleration data DA are similarly set in the data setting section P2. The unit controller 11A or 11B receives the data of the divided scan sections SA and SB from these input panels 21A or 21B. Then, as described below, the actual processing liquid application processing is performed in accordance with a processing sequence specification called a recipe in which the operation specifications of each unit at the time of applying the processing liquid are determined. FIG. 7 is an example of a recipe. This example is based on the fifth
This is a case where data is set as described above in the data setting units P1 and P2 when the entire scan section in the drawing is 80 mm. In the case of this example, in the recipe, one scan time has a plurality of sections, in the example of the figure, six sections SEQ1 to SEQ6.
Are divided into The time of each section (split scan time), the number of rotations of the chuck in that section, that is, the wafer, and the rotational acceleration are assigned as shown in the figure. That is, in this example, the rotation speed of the wafer is changed in each section. In addition, setting data used in each section is allocated. In this example, the sections SEQ1 to SEQ5 mean that the data set in the data setting sections P1 and P2 is used. That is, the data set from the unit controller 11A or 11B is sent to the speed controller 20. No data is assigned in section SEQ6, which means that these data are not sent to speed controller 20. The speed controller 20 performs speed control according to these data while the data set in the data setting units P1 and P2 is being sent.In the section SEQ6 where no data is sent, the nozzles are set at a predetermined speed. To return to the original position. In FIG. 7, S1 is
This indicates that a developing solution, that is, a resist coating process is performed. FIG. 8 is a diagram showing the movement of the nozzle according to the above-described recipe and the change in speed thereof. With reference to FIG. 8, the developing solution applying operation of this example will be described. That is, when a start command of the processing liquid application processing is given to the unit controller, a start signal is given from the unit controller 11A or 11B to the speed controller 20 in the section SEQ1 and the data setting unit P1 and
The data of P2 is sent to the speed controller 20. Then
The speed controller 20 accelerates the stepping motor 35 to the target speed at the ratio of the speed value and the acceleration value set in the data setting unit P1. Then, a developer is supplied to the wafer from the nozzle at a rate of, for example, 20 cc / sec. Thereafter, the developing solution is supplied from the nozzle to the semiconductor wafer at a constant rate in this ratio. Also, in this section SEQ1, the wafer rotation speed
It is controlled by the unit controller 11A or 11B to rotate at 500 rpm. When the scan delay time is set, the stepping motor 35 starts rotating after the scan delay time has elapsed. After the elapse of the scan delay time, the developer is supplied to the wafer from the nozzle. When accelerated to the target speed, in this example 30 mm / sec, the stepping motor 35 at that speed during the scan time of the divided scan section SA, ie during section SEQ1,
The nozzle is fixed and moves at the moving speed. When the scanning time set in the data setting section P1 elapses and the section becomes SEQ2, the stepping motor 35 is controlled by the speed controller 20 at the ratio of the speed value and the acceleration value set in the data setting section P2 to the target speed, which is 65 mm65 0.8
It is accelerated to 81.25 mm / sec. When accelerated to the target speed, the stepping motor
35 is fixed at that speed during the scan time of the divided scan section SB, that is, during the sections SEQ2 to SEQ5,
The nozzle moves at the moving speed. However, the rotation speed of the wafer is 1000 rpm in section SEQ2 and section S
It is controlled by the unit controller to 800 rpm for EQ3, 1500 rpm for section SEQ4, and 2000 rpm for section SEQ5. After the time set in the data setting section P2 elapses, section SE
At Q6, the supply of the developing solution from the nozzle is stopped, the stepping motor 35 is decelerated and stopped by the speed controller 20, and the nozzle is returned to the original start position. At this time, the rotation speed of the wafer is set to 4000 rpm by the unit controller, so that the developer is more uniformly applied to the wafer. As described above, the moving speed of the nozzle is set to a different value for each divided scan section. In this case, the moving speed of the nozzle is as fast as 81.25 mm / sec at a position near the center of the semiconductor wafer and relatively slow as 30 mm seconds at a position near the outer peripheral edge. Therefore, even if the processing liquid is supplied to the surface of the semiconductor wafer from the nozzle by a fixed amount, it is possible to prevent a portion where the processing liquid is not applied to the surface of the semiconductor wafer from occurring. Of course, the operator can change the setting data and select the setting data that allows the processing liquid to be applied to the surface of the wafer almost uniformly. According to the above example, the scanning section of the nozzle in one process can be divided into a plurality of sections, and the moving speed of the nozzle can be set arbitrarily in each divided scanning section. Optimum nozzle movement control can be performed in accordance with the above. Also, in the above example, the rotational speed of the semiconductor wafer was changed in relation to the movement of the nozzle,
Control at the time of applying the treatment liquid can be performed more finely. In the above example, the moving speed of the nozzle is gradually increased, but the setting data of the data setting unit P2 or P3 is set to a target speed that is lower than the moving speed of the preceding divided scan section. By setting such that, the moving speed can be reduced. It goes without saying that the movement speed can be increased or decreased in the same manner. Although the above example is for a case where the number of divided scan sections is three, any number of divided scan sections may be provided depending on the application. Further, in the above embodiment, the case where the moving speed of the nozzle is changed to change the amount of the processing liquid to be processed between the rotation center portion and the peripheral portion, but the moving speed of the nozzle is kept constant. By changing the supply amount of the processing liquid from the nozzle, by intermittently injecting the processing liquid from the nozzle, or by changing the injection amount itself from the nozzle,
You may make it change the processing liquid amount in the rotation center part and peripheral part of a to-be-processed object. In the above embodiment, one nozzle is scanned. However, a plurality of nozzles may be arranged in the radial direction of the semiconductor wafer, and the processing liquid may be simultaneously dropped from each nozzle. Simultaneous dropping and supply can alleviate faster drying of the developer in the periphery due to the difference in peripheral speed.

【The invention's effect】

According to the present invention, the processing liquid amount is changed between the rotation center portion and the peripheral portion of the object rotating at a constant angular velocity, so that the radial distance from the rotation center of the object is different. At any position, the amount of the processing liquid applied to the object to be processed is uniform, and there is no place where the processing liquid is not applied.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an electrical configuration of a processing apparatus according to the present invention, FIG. 2 is a view showing an example of a mechanical configuration of a main part of the apparatus according to the present invention, and FIG. FIG. 4 is a block diagram illustrating an example of a drive control circuit of a drive motor, FIG. 4 is a diagram illustrating an example of an input panel for setting a moving speed, and FIG. 5 is a diagram illustrating an example of nozzle scanning; , FIG. 6 is a diagram showing an example of a table used when setting the data of the moving speed of the nozzle, FIG. 7 is a diagram showing an example of operation specifications of each part at the time of applying the processing liquid, FIG. FIG. 4 is a diagram showing the movement of a nozzle and its speed change. 11A, 11B; Unit controller 13A, 13B; Processing unit 20; Speed controller 21A, 21B; Input panel 31; Nozzle plate 32; Sliding body 35; Stepping motor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-15773 (JP, A) JP-A-62-183885 (JP, A) JP-A-63-107768 (JP, A) 51976 (JP, A) JP-A-1-236971 (JP, A) JP-A-1-218664 (JP, A) JP-A-59-102177 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B05C 7/00-21/00 H01L 21/30 G03F 7 / 16,7 / 30

Claims (3)

(57) [Claims] A processing liquid is supplied onto the object to be processed by applying a processing liquid to the object while moving a processing liquid supply nozzle in the direction of a radius of rotation above the object to be rotated. In the processing apparatus, the moving section of the processing liquid supply nozzle is divided into a plurality of sections, and the rotation speed of the object to be processed in each of the divided moving sections is switched and controlled in accordance with the position of the divided moving section in the rotational radial direction. A processing device, comprising: a rotation speed control unit that performs rotation speed control. 2. A processing liquid is supplied onto the object to be processed and applied to the object while the processing liquid supply nozzle is moved in the radial direction of rotation above the object being rotated. In the processing apparatus, the moving section of the processing liquid supply nozzle is divided into a plurality of sections, and the supply amount of the processing liquid from the processing liquid supply nozzle in each of the divided moving sections is controlled to a desired value. Amount control means, and rotation speed control means for switching and controlling the rotation speed of the processing object in each of the divided moving sections according to the position of the processing liquid supply nozzle in the rotation radial direction of the processing object. A processing device, comprising: 3. The processing apparatus according to claim 1, wherein said processing liquid is a developing processing liquid.