JP3260117B2 - Processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus used, for example, for exposing and developing semiconductor wafers.

[0002]

2. Description of the Related Art When a photoresist film is applied to a semiconductor wafer before exposure processing or when a developing solution is applied to the surface of the semiconductor wafer, the photoresist material and the developing solution are supplied to a nozzle placed above the semiconductor wafer. From the surface of the semiconductor wafer.

As an example of this, a semiconductor wafer is vacuum-sucked on a chuck and rotated in a semi-fixed state, and a nozzle is moved linearly at a constant speed toward a center of rotation which is the center of the semiconductor wafer. 2. Description of the Related Art There is known a method in which a processing liquid is supplied to a semiconductor wafer in an amount by amount to apply the processing liquid.

[0004]

Since the semiconductor wafer is rotated at a constant angular velocity, the distance in the rotational direction at the same time differs at the position on the wafer where the distance d from the center of rotation is different. Become. 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, conventionally, a predetermined amount of processing liquid is supplied dropwise from a nozzle that moves linearly at a constant speed to a wafer. 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.

[0006] In addition, the viscosity and concentration vary depending on the processing liquid, and when the moving speed of the nozzle is constant, the rotation speed of the wafer is constant, and the amount of the processing liquid is constant, it is often impossible to uniformly apply the processing liquid to the surface of the workpiece.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention 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.

[0008]

According to a first aspect of the present invention, there is provided a processing apparatus, comprising: moving a processing liquid supply nozzle in a rotation radial direction above a rotating object; In a processing apparatus for supplying a processing liquid onto the processing object and applying the processing liquid to the processing object, a moving section of the processing liquid supply nozzle is divided into a plurality of sections, and the processing liquid in each of the divided moving sections is divided. The nozzle moving speed setting means for setting the moving speed of the supply nozzle to a desired speed value, and the moving speed of the processing liquid supply nozzle in each of the divided moving sections are set by the nozzle moving speed setting means. A nozzle moving speed control means for controlling a speed value, and a rotational speed of the object to be processed in each of the divided moving sections, in accordance with a position of the processing liquid supply nozzle in a rotational radial direction of the object to be processed. A rotational speed control means for Toggles control, characterized in that it comprises a.

[0009]

In the processing apparatus according to the first aspect of the present invention, the moving section of the processing liquid supply nozzle is divided into a plurality of sections in accordance with the position of the object to be processed in the radial direction of rotation, and each of the moving sections is divided. Is controlled to the speed value set by the operator. In each of the divided moving sections, the rotation speed of the object to be processed is controlled to be switched according to the radial position of the processing liquid supply nozzle in the rotational direction.

Therefore, the amount of the processing liquid applied to the rotating object to be processed becomes appropriate in accordance with each position of the object to be processed in the radial direction of the object to be rotated, and is uniform over the entire object to be processed. A treatment liquid can be applied.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an example of an electrical configuration in a case where the apparatus according to the present invention is applied to a surface treatment apparatus for developing a semiconductor wafer.

In this example, two semiconductor wafers can be processed at the same time.
There is a line. Each system has unit controllers 11A and 11B,
Joint boxes 12A, 12B and processing units 13A,
It consists of 13B. Each of the processing units 13A and 13B and the unit controllers 11A and 11B has a microcomputer (hereinafter referred to as a CPU).
Processing units 13A, 13B in response to control commands from A, 11B.
B performs a predetermined process.

The processing units 13A and 13B are provided with a chuck for fixing the semiconductor wafer by vacuum suction and 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 constructed, 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.
Reference numeral 31 denotes a nozzle plate to which nozzles are 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. Reference numeral 33 denotes a ball screw, on the outer peripheral surface of which is formed a screw that meshes with the screw on the inner peripheral surface of the through hole of the sliding body 32. 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 moves according to the rotation direction.
The sliding motion is performed along the ball screw 33 rightward or leftward in the figure. As a result, the nozzle moves linearly over the semiconductor wafer.

Reference numeral 34 denotes a guide for guiding the sliding movement of the sliding body 32. 35 is a stepping motor. A pulley 37 is attached to a rotating shaft 36 of the ball screw 33, and a timing belt 39 is wound between the pulley 38 and a pulley 38 attached to the rotating shaft of the stepping motor 35. It is transmitted to the rotating shaft. By controlling the rotation of the stepping motor 35, the sliding motion of the sliding body 32, that is, the moving speed of the nozzle is controlled.

Reference numeral 40 denotes a sensor mounting portion, which is provided along the ball screw 33. This sensor mounting part
In 40, a plurality of sensors for knowing the position of the sliding body 32, that is, the position of the nozzle, can be attached to any 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 shared by the two systems A and B,
As will be described later, the moving speed setting data of the nozzle is sent to the unit controllers 11A and 11B, respectively, and in response to a control command from the unit controllers 11A and 11B,
Controls the moving speed of the nozzle.

Reference numerals 21A and 21B denote input panels for setting data such as the moving speed of each nozzle of the system A and the system B. The input data from the input panels 21A and 21B is input to the speed controller 20 via the selector 22. The CPU of the speed controller 20 controls the selector 22 to select the input data from the input panel 21A or 21B. Unit controller 11
The input data is transferred to the CPU of A or 11B.

In this speed controller 20, the control of the moving speed of the nozzle is performed by the processing units 13A of the respective systems A and B.
13B and 13B by controlling the drive pulse supplied to the stepping motor 35. In this case,
The drive control circuit of the motor 35 is configured by hardware,
It is provided for each of the processing units 13A and 13B. Then, output pulses of the drive control circuit are supplied to the stepping motors 35 of the respective systems.

FIG. 3 shows an example of a drive control circuit for the stepping motor 35. This circuit is provided for each of the systems A and B.

An oscillator 41 generates a pulse having a frequency of, for example, 3.072 MHz. 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 422. 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
The target speed of the stepping motor 35 is supplied to a determination circuit 43. This target speed determining circuit 43 is a second variable frequency dividing circuit.
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. The output pulse Po of the target speed determination circuit 43 is supplied to the stepping motor 35.

In this case, the output pulse of the acceleration determination circuit 42
Assuming that the frequency of Pa is fa and the frequency of the output pulse Po of the target speed determination circuit 43 is fo, the stepping motor 35 changes its speed at an acceleration determined by the output pulse fa until reaching a speed corresponding to the target frequency fo. Will be. 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 dividing ratio of the first variable frequency dividing circuit 421
The N value of 1 / N is ACC and that of the second variable frequency divider 431 is SP
When ED is set, the frequency fo of the output pulse Po is obtained by the following equation.

Fo = 3072000 / (ACC × 2 × SPED × 2) = 768000 / (ACC × SPED) [Hz] (a) The stepping motor 35 rotates at a rotation frequency corresponding to the frequency fo of the output pulse Po. .

Here, SPED 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, using the drive control circuit of FIG. 3, the moving speed of the nozzle in one application of the developing solution is not constant but can be changed in a plurality of 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 first and second variable frequency divisions are performed in each divided scan section. The preset value to be supplied to the circuit is set so that it is applied uniformly on the entire surface of the wafer, and the moving speed of the nozzle during each divided scan period can be changed to the speed set by the set acceleration. ing. The setting of the speed and the setting of the acceleration are performed by the input panels 21A and 21B, and the whole control in one processing liquid application is performed by a unit controller.
11A and 11B do.

Hereinafter, the setting operation for one processing liquid application and the unit controller 11A and
The processing operation by 11B will be described.

FIG. 4 shows an example of the input panel 21A or 21B. In the case of this example, one scan can be divided into three parts. Therefore, the data setting units P1 and P2
2, P3.

In this example, the data setting items are, in order from the left side of the figure, the speed data DV for the target speed SPEED, the acceleration data DA for the acceleration ACCELERATION, the divided scan time SCAN TIME (divided scan section), and the scan delay time SCAN DELAY TIME. And four items.

In this example, the speed data DV represents the minimum value [000] when the speed is represented by a three-digit value (decimal system).
To a maximum value [254]. Similarly, the acceleration data DA ranges from the minimum value [255] to the maximum value [001].

The values ACC and SPED in the above equation (a)
And the relationship between the acceleration data DA and the velocity data DV is as follows. That is, ACC = DA (three-digit decimal number) SPED = 255-DV (three-digit decimal number)

The scan delay time is the 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 section 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, as shown in FIG. 5, for example, when a single scan distance is set to 80 mm, the distance is divided into a first half 15 mm divided scan section SA and a second half 65 mm divided scan section SB. A case where the scan speed is changed in two stages is taken as an example.

In the case of the above example, the data setting unit is P1
And P2 are used.

First, the data setting section P1 sets the scan time of the divided scan section SA to, for example, 0.5 second.
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 = 555.5 Hz.

Next, based on the rotation frequency of the stepping motor, a list of speed data DV and acceleration data DA as shown in FIG. 6 (this is prepared in advance)
And obtain appropriate acceleration data DA and velocity data DV from 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.

Similarly, for the divided scan section SB, the scan time, velocity data DV, and acceleration data DA are 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 part at the time of applying the processing liquid are defined.

FIG. 7 shows an example of a recipe. This example is a case where the data is set as described above in the data setting units P1 and P2 when the entire scan section in FIG. 5 is 80 mm.

In the case of this example, in the recipe, one scan time is a plurality of sections, in the example of the figure, 6 sections SE.
It is divided into Q1 to SEQ6. 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 correspond to the data setting section P
This means that the data set in 1 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.

In the speed controller 20, the data setting section P
While the data set in P1 and P2 are being sent, speed control according to these data is performed. In the section SEQ6 where data is not sent, the operation of returning the nozzle to the original position at the determined speed is performed. I am trying to do it. In FIG. 7, S1 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 the 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 to the speed controller 20 in the section SEQ1 from the unit controller 11A or 11B, and the data of the data setting sections P1 and P2 are sent. It 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. And
A developer is supplied to the wafer from the nozzle at a rate of, for example, 20 cc / sec. Thereafter, from the nozzle,
The developer is supplied to the semiconductor wafer by a fixed amount.

In this section SEQ1, the unit controller 11A or 11B controls the wafer to rotate at a wafer rotation speed of 500 rpm. When the scan delay time is set, the stepping motor 35 starts rotating after the scan delay time has elapsed. Also,
After the elapse of the scan delay time, the developer is supplied to the wafer from the nozzle.

When the stepping motor 35 is accelerated to a target value speed, in this example, 30 mm / sec, the stepping motor 35 at that speed during the scan time of the divided scan section SA, that is, the section
During SEQ1, the nozzle is fixed and the nozzle moves at the moving speed.

When the section SEQ2 is reached after the elapse of the scan time set by the data setting section P1, the speed controller 20
Accordingly, the stepping motor 35 is accelerated to the target speed, in this example, 65 mm６５0.8 seconds = 81.25 mm / second, at the ratio of the speed value and the acceleration value set by the data setting unit P2.

When the stepping motor 35 is accelerated to the target value 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, and the nozzle moves at that moving speed. . However, the rotation speed of the wafer is 1000 rpm in section SEQ2.
, 800 rpm for section SEQ3, 1500 rpm for section SEQ4, 2000 rpm for section SEQ5,
It is controlled and changed by the unit controller.

When the time set in the data setting section P2 elapses and section SEQ6 is reached, 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. Is returned to. 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
A different value is set for each divided scan section. Also,
The rotational speed of the wafer has also been changed.

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 in various ways to select the setting data that allows the processing liquid to be applied almost uniformly to the surface of the wafer.

According to the above example, the nozzle scanning section for one processing 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 according to the moving speed of the nozzle.

In the above example, since the rotation speed of the semiconductor wafer is changed in relation to the movement of the nozzle, the control at the time of applying the processing liquid can be performed more finely.

In the above example, the moving speed of the nozzle is gradually increased. However, the setting data of the data setting unit P2 or P3 is changed to a speed lower than the moving speed of the preceding divided scan section. Is set to be the target speed, 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.

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 constant. And changing the supply amount of the processing liquid from the nozzle by interrupting the injection of the processing liquid from the nozzle, or by changing the injection amount itself from the nozzle, so that the rotation center portion of the object to be processed and the periphery thereof are changed. Alternatively, the amount of the processing liquid between the sections may be changed.

In the above embodiment, one nozzle is scanned, but 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.

[0065]

As described above, according to the present invention, the amount of the processing liquid to be applied is changed between the rotation center portion and the peripheral portion of the object to be processed. At any position where the distance in the radial direction is different, the application amount of the processing liquid 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 of an electric configuration of an embodiment of a processing apparatus according to the present invention.

FIG. 2 is a diagram showing an example of a mechanical configuration of a main part of an embodiment of the processing apparatus according to the present invention.

FIG. 3 is a block diagram illustrating an example of a drive control circuit of a motor for driving the movement of a nozzle.

FIG. 4 is a diagram showing an example of an input panel for setting a moving speed.

FIG. 5 is a diagram for explaining an example of nozzle scanning.

FIG. 6 is a diagram illustrating an example of a table used when setting data of a moving speed of a nozzle.

FIG. 7 is a diagram illustrating an example of operation specifications of each unit when applying a processing liquid.

FIG. 8 is a diagram showing a movement of a nozzle and a change in speed thereof.

[Explanation of symbols]

 11A, 11B; Unit controller 13A, 13B; Processing unit 20; Speed controller 21A, 21B; Input panel 31; Nozzle plate 32; Sliding body 35;

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuro Nakahara 2655 Tsukure, Kikuyo-cho, Kikuchi-gun, Kumamoto Prefecture Tokyo Electron Kyushu Co., Ltd. Kumamoto Office (56) References JP-A-63-51975 (JP, A) JP-A-62-183885 (JP, A) JP-A-59-225769 (JP, A) JP-A-61-15773 (JP, A)

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 moving speed of the processing liquid supply nozzle in each of the divided moving sections is
A nozzle moving speed setting unit for setting each to a desired speed value; and a nozzle moving unit for controlling a moving speed of the processing liquid supply nozzle in each of the divided moving sections to a speed value set by the nozzle moving speed setting unit. Speed 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 radial direction of rotation of the processing object. A processing device, comprising: 2. While moving the processing liquid supply nozzle,
After supplying the processing liquid to the rotating object to be processed, the supply of the processing liquid is stopped, and when the processing liquid supply nozzle is moved back to the original position, the nozzle moving speed control means is used. 2. The processing apparatus according to claim 1, wherein the control by the control unit is made free. 3. The processing apparatus according to claim 1, wherein said processing liquid is a developing processing liquid.