JP2003282416A - Method for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for monitoring the suitability of a film-forming material feed rate, which can spread failures in film formation. <P>SOLUTION: In forming a film by a spin coating method, light is projected from an optical sensor 21 over Al chelated liquid 30a serving as a film-forming material 30, which has been dropped on the surface of a wafer W. Then the reflectance of the reflected light is compared with threshold reflectance in a case where an appropriate amount is dropped, thereby deciding the suitability of the dropping ratio. The optical sensor 21 is constituted of a projector 22 and an optical receiver 23 which are connected to a sensor amplifier via an optical fiber. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device manufacturing technique, and in particular, it is applied to a technique for determining the adequacy of a film forming material supply amount when forming a film by a coating method in a semiconductor device manufacturing process. It is valid.

[0002]

2. Description of the Related Art The techniques described below are for studying the present invention,
The present invention was studied by the present inventors upon completion, and its outline is as follows.

Various film forming techniques are used in the method of manufacturing a semiconductor device. A coating method such as a spin coating method is known as one of such film forming techniques. In the spin coating method, the film-forming material is supported on a rotation support table capable of high-speed rotation, and a prescribed amount of the film-forming material is dropped onto the film-forming surface of the supported film-forming material. In this state, by rotating the rotary support table at a high speed, the film forming material on the rotating film forming surface is thinly applied to the film forming surface by centrifugal force to form a thin film.

In the film formation by the spin coating method,
By controlling the viscosity of the film-forming material to be dropped, the dropping amount, and the number of rotations of the film-forming material, it is managed so that coating defects such as coating omissions and uneven film thickness do not occur.

Of these, in particular, coating omissions are often due to a shortage of the amount of film forming material dropped. As a method of managing the adequacy of the dropping amount, there are known a method of judging the adequacy of the dropping amount based on an image and a method of monitoring the abnormality of the supply system directly related to the dropping amount.

The method based on image judgment is based on the premise that the spread state before coating when a film-forming material having a prescribed viscosity is dropped shows a substantially constant spread state.

Therefore, in such image judgment, an appropriate amount of a film-forming material having a specified viscosity is dropped onto a film-forming material supported on a spin-coating rotary support, and the film-forming material is dropped before spin-coating in that state. The spread state of the film material is photographed by a CCD camera or the like and used as comparison reference image data.

On the other hand, even when a film is formed by the spin coating method, a film forming material adjusted to have a specified viscosity is dropped on the surface to be filmed each time, and in that state, the film forming material before spin coating is formed. Capture the image data by capturing the spread state. This image data is compared with the image data of the comparison reference, and the adequacy of the dropping amount of the film forming material is determined depending on whether the spread state is larger than the reference image data. When the spread state is smaller than the reference image data, it can be determined that the supply amount is small.

Further, it is possible to prevent the film formation failure by monitoring the supply system for the film formation material.
For example, in a photoresist process, a specified amount of resist may be dropped onto a film-forming surface through a resist discharge dispenser system, and then a spin coater may be used to form a resist film. By detecting abnormalities in the air operated valve, the air driving solenoid valve, etc., it is possible to monitor whether or not the resist discharge is normally performed, and check the supply amount shortage due to the resist discharge failure. ing.

[0010]

However, the present inventor has found that the above-described technique for determining the amount of film forming material dropped has the following problems.

That is, in determining the suitability of the amount of the film-forming material to be dropped onto the film-forming surface, a method of capturing the spread state before coating as image data and comparing it with the reference of the spread state at the time of dropping an appropriate amount is used. However, the system configuration of the image processing configuration becomes expensive, resulting in an increase in equipment cost, and it is not possible to meet the demand in such a field where cost reduction is strongly required.

On the other hand, in the monitoring method based on the abnormality of the supply system of the film forming material, when there is an abnormality from the air operate valve, the air driving electromagnetic valve, etc., it is indirectly estimated that the supply amount is abnormal. Therefore, if an abnormal signal is detected due to an electrical failure or the like despite the proper operation and supply of a proper amount, the judgment will be erroneous.

Further, even when an abnormal operation is performed and an appropriate amount is not actually supplied, if an abnormal signal is not detected due to an electrical failure or the like, coating failure will be overlooked.

As described above, in the indirect monitoring method based on the abnormality detection of the supply system, the monitoring cost can be kept low, but the reliability of the monitoring is higher than that in the case of directly determining the supply state by the image. There is a problem that is inferior.

In view of such problems, the present inventor needs to develop a method for directly monitoring the spread state of the film-forming material with a simple structure without using a complicated structure such as image processing. Thought.

An object of the present invention is to provide a technique for directly monitoring the adequacy of the supply amount of a film forming material, which leads to a film forming defect, with a simple structure.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0018]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, in the present invention, the amount of the film-forming material to be dropped is measured using an optical sensor in a predetermined time after the film-forming material having an appropriate viscosity is dropped onto the surface to be filmed in advance. Is set as a threshold value for comparison. By comparing the threshold value with the amount of the dropped film forming material measured using the same optical sensor in the actual film forming process, it is possible to directly detect the abnormality in the supply amount with a simple configuration.

For example, in a state in which an appropriate amount of a film-forming material having a proper viscosity is previously dropped on the film-forming surface, light is projected before coating toward the film-forming material for a certain time after the dropping, and the amount of reflection of the light is reflected. Is set as a threshold. On the other hand, when the amount of reflection is larger than the threshold value by comparing the amount of reflection measured by projecting light before coating to the threshold value toward the dropped film forming material during actual film formation It can be determined that the material has an abnormal drop amount and the drop amount is insufficient.

If such a technique is applied, for example, when forming an adhesive film such as an Al chelate film in advance for film adhesion when forming a film such as a protective film on the film formation surface, the adhesive film material can be covered. By properly controlling the amount dropped onto the film formation surface, a polyimide resin film (for example,
The peeling of a protective film such as a PIQ film) can be prevented in advance, and it can be effectively used to prevent defects in semiconductor products.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. In all the drawings for explaining the embodiments, members having the same function are designated by the same reference numeral, and repeated description thereof will be omitted.

FIG. 1A is a cross-sectional view of a main part when a semiconductor manufacturing apparatus used in the method of manufacturing a semiconductor device of the present invention is configured as a spin coater, and FIG. 1B is a plan view of the main part. is there. FIG. 2 is an explanatory view of the principal part showing an enlarged part surrounded by a circle in FIG. FIG. 3 is an explanatory diagram showing a flow of determining whether or not the deposition amount of the film forming material is appropriate by the optical sensor.

As shown in FIG. 1 (b), a semiconductor manufacturing apparatus 10 constituted by a spin coater 10a supports a rotating body in a coating cup 11 formed in a cylindrical shape and tapered upward inward. The spin chuck 12 is supported by a rotation shaft 14 so that it can be rotated at a high speed by a motor 13. The spin chuck 12 is formed in a circular flat plate shape, and the wafer W on which the film is to be formed is detachably mounted and fixed on the film formation surface.

A coating nozzle 15 is provided above the spin chuck 12 so that the film forming material can be dropped toward the rotation center of the wafer W fixed to the spin chuck 12. That is, the discharge port 15a of the coating nozzle 15 is
It is opened vertically downward in the direction of the rotating shaft 14. The coating nozzle 15 is connected to an air-operated valve and a supply system (tispenser system) of an electromagnetic valve for air drive (not shown) so that the dropping amount of the film-forming material to be dropped can be controlled to a prescribed amount.

On the side of the coating nozzle 15, an optical sensor 21 is provided which is used to judge the adequacy of the amount of film-forming material to be dropped. The optical sensor 21 is provided on the nozzle bracket 16 that supports the application nozzle 15, and is fixed so that the interval between the application nozzle 15 and the optical sensor 21 does not change. The coating nozzle 15 is connected to a dispenser system including an air operate valve and an air driving electromagnetic valve (not shown) so that a predetermined amount of film forming material can be dropped through the coating nozzle 15.

The optical sensor 21, as shown in FIGS.
It is composed of a light projecting section 22 and a light receiving section 23. As shown in FIG. 3, the light projecting section 22 and the light receiving section 23 are connected to a sensor amplifier 24 via optical fibers 22a and 23a, respectively.

Light of a predetermined wavelength from a light source provided on the sensor amplifier 24 side is dropped from the light projecting section 22 through the optical fiber 22a onto the film formation surface of the wafer W supported on the spin chuck 12. It is projected toward the film forming material. The projected light passes through the film-forming material and is reflected on the film-forming surface, and the reflected light enters the light-receiving section 23 and is sent from the optical fiber 23a to the sensor amplifier 24. The sensor amplifier 24 calculates the reflectance by converting the light amount of the reflected light sent via the light receiving unit 23 when the light amount at the time of light projection is 100.

The reflectance is compared with the reflectance as a threshold value obtained when an appropriate amount of the film-forming material is dropped in advance. If the reflectance value exceeds the threshold value, the alarm signal does not exceed the threshold value. Is sent a normal signal.

On the basis of the transmission signal, it is judged in step S1 whether or not the film forming material is properly ejected, and if the result is YES, the spin coating is started in step S2. That is, the spin chuck 12 of the spin coater 10a rotates at a high speed, the film forming material dropped on the wafer W is spread by a centrifugal force, and a film is formed on the target film surface.

On the other hand, if the signal is an alarm signal, it is determined in step S1 that the ejection of the film forming material is inappropriate, and the spin coating in step S2 is interrupted by interrupt control as NG.

Next, using the spin coater 10a shown in FIG. 1, a PIQ as a protective film (passivation film) is formed on the entire surface of the wafer W having a circuit pattern formed on a Si substrate.
A method of manufacturing a semiconductor device in which a film (polyimide resin film) is formed with an Al chelate film as an adhesive film will be described.

In the semiconductor device in this description, the wafer W
Is formed, for example, through the following semiconductor process. That is, an oxide film of SiO ₂ is formed on a substrate (Si wafer), and a nitride film is formed on the oxide film by vapor phase epitaxy. After that, a thin film of a photoresist of photosensitive resin is formed on the nitride film, and a circuit pattern is baked by ultraviolet irradiation using a predetermined mask with a stepper.

After that, the unexposed portion of the photoresist is melted with a developer and developed. After development, the photoresist is baked and the remaining photoresist is used as a mask to etch the nitride film and the silicon oxide film. After etching, the resist is removed by ashing and the wafer is washed.

After cleaning, the wafer is put into an oxidation furnace, a silicon oxide film for element isolation is formed on the surface by using the remaining nitride film as a mask, and then the nitride film is removed by high temperature phosphoric acid or the like. The oxide film is also removed with a hydrofluoric acid solution and washed.

After cleaning, a thin silicon dioxide film is formed as a gate insulating film, a polycrystalline silicon film is further deposited thereon, and an N-type conductivity type impurity is added to this polycrystalline silicon film.

Further, a gate electrode pattern is processed on the polycrystalline silicon film by photolithography. In this way, a mask made of a polycrystalline silicon film formed in the gate electrode pattern is formed, and using the gate electrode film as a mask, arsenic is ion-implanted into the substrate surface through a thin silicon dioxide film to form a pair of N-type regions, Source/
A drain region is formed.

After that, an interlayer insulating film such as a silicon oxide film is deposited on the entire surface of the wafer by a vapor phase growth method or the like. A contact hole for drawing out an electrode is formed in the interlayer insulating film, and thereafter, an aluminum film to be a wiring is deposited, and the aluminum film is processed into a desired wiring pattern by photolithography. Thus, in the wafer W, the circuit pattern is formed on the Si substrate.

The wafer W on which the circuit pattern has been formed in this manner is, as shown in FIG. 1, a spin coater 10a.
It is placed and fixed on the spin chuck 12 of FIG. On the surface of the fixed wafer W, that is, on the film formation surface, a prescribed amount of A is applied from the coating nozzle 15 toward the rotation center side.
The 1 chelate liquid 30a is dropped as the film forming material 30. The Al chelate liquid 30a dropped on the wafer W has a predetermined viscosity adjusted so as not to spread at once.

After a lapse of a certain time after the dropping of the Al chelate solution 30a, that is, at a stage where a certain spread state is exhibited based on the viscosity of the Al chelate solution 30a, the light projecting portion 22 of the optical sensor 21 is shown in FIG. So that the Al chelate solution 3
Light is directed toward the pool showing the spread state of 0a. The projected light passes through the Al chelate liquid 30a, reaches the surface of the wafer W, that is, the film formation surface, and is reflected by the film formation surface of the wafer W.

A certain amount of the reflected light is absorbed during the transmission of the Al chelate solution 30a, so that the reflected light having a smaller reflected light amount than the projected light amount enters the light receiving portion 23.

That is, when the dropping amount of the Al chelate solution 30a is large, the attenuation amount of the reflected light amount is large, and when it is small, the reflected light amount is small.

Therefore, the initial state of the optical sensor 21 is adjusted in advance so that the light projection amount and the reflection amount are equal without dropping the Al chelate solution 30a, and the reflectance in this case is set to 100%. After performing such initial adjustment, the reflectance when an appropriate amount of the Al chelate solution 30a is dropped on the wafer W is obtained, and this is set as a threshold value.
For example, the threshold value in this case is set to 50% as shown in FIG.

A on the wafer W at the time of forming the Al chelate film
Appropriateness of the dropped amount of the 1 chelate solution is judged by comparing such a threshold value with the reflectance of the light projected toward the Al chelate solution 30a dropped on the wafer W at the time of forming the adhesive film. That is, the reflected light is received by the light receiving unit 23 and sent to the sensor amplifier 24 through the optical fiber 23a, the reflectance is calculated by the sensor amplifier 24, and the result is compared and compared with the reflectance of 50% as a threshold value. The suitability is judged by whether or not the reflectance is higher than 50%.

For example, as shown in FIG. 2, the reflectance is 50.
If it exceeds%, the amount of the Al chelate solution dropped is less than the specified amount, and it is determined that the amount of dropping is insufficient, and the sensor amplifier 24 issues an alarm signal. In this case, the subsequent spin coating is interrupted. After removing the wafer W on the spin chuck 12 to eliminate the cause of the drop defect, the Al chelate solution 3 on another wafer W is removed again.
The adhesive film of 0a may be formed.

On the other hand, when the reflectance is 50% or less, it is determined that at least the specified amount of the Al chelate solution has been dripped, and thereafter, the Al chelate solution is driven by the spin coater 10a to form the film on the wafer W. The surface is thinly applied to form an Al chelate film as an adhesive film.

After the Al chelate film is formed on the front surface of the wafer in this way, the PIQ film is formed thereon as a protective film (passivation film) to manufacture a semiconductor device.

FIG. 4 schematically shows the situation of judgment as to whether or not the dropping amount of the Al chelate solution is appropriate. In the figure, T1 shows the situation before the dropping of the Al chelate solution. T2
Is a dead zone situation in which the Al chelate solution has been dropped, and light emission has been started to the dropped Al chelate solution, and the comparison with the threshold value has not yet been made. T3 is projected to the dropped Al chelate solution. The situation where the amount of reflected light is compared with a threshold value is shown.

At T4, after checking the adequacy of the dropping amount of the Al chelate solution by the optical sensor, the reflection amount at the stage when the Al chelate film is formed on the spin coater 10a is measured and compared with the threshold value. It is a thing.

In FIG. 4, the light projection and reflection amount 100
% Of reflected light is indicated by a solid arrow, and attenuated reflected light is indicated by a dashed arrow.

FIG. 5A shows a monitoring operation chart when the dropping is normal, and FIG. 5B shows a monitoring operation chart when the dropping abnormality is detected. The sensor output corresponding to the monitoring chart is output and displayed as either high (indicated by H in FIG. 5) or low (indicated by L in FIG. 5) indicating whether the sensor output is high or low with respect to the threshold value. In the case shown in FIG. 5, the reflectance of 50% corresponding to the normal dropping of the Al chelate solution 30a is set as the threshold value.

In the case of FIG. 4A, under the condition of T1 described above, the light projected from the light projecting section 22 is reflected on the wafer W surface and the reflectance at the light receiving section 23 is 100%. The case is shown. The monitoring operation by the optical sensor 21 in such a case is a flat monitoring chart with a reflectance of 100% at the portion corresponding to T1 in FIGS. 5A and 5B.
Since the sensor output corresponding to the monitoring chart indicated by T1 is higher than the threshold value of 50% as shown in FIGS. 5A and 5B, a flat output is made at the H level.

In the case shown in FIG. 4B, from T2 to T
Under the conditions up to 3, that is, from the coating nozzle 15 to Al
A certain amount of the chelate solution 30a is dropped on the wafer W, light having a predetermined wavelength is projected from the optical sensor 21 onto the dropped Al chelate solution 30a, and the reflectance is measured through a dead zone immediately after the projection and a threshold value is obtained. The case of comparison is shown.

The monitoring operation by the optical sensor 21 at T2 and T3 is as shown in FIG. 5A when the drop amount is normal.
As shown in FIG. 7, the reflectance of the projected light is measured at each depth as the light gradually penetrates deeply into the Al chelate solution 30a layer, and the reflectance is such that the depth of light transmission becomes deep. Therefore, since it attenuates gradually, an attenuation straight line is displayed as an oblique straight line.

The sensor output corresponding to such a monitoring chart is displayed as an L level flat output when the attenuation straight line showing the reflectance becomes lower than the threshold value, that is, when the condition of T3 is entered.

On the other hand, when the dropping abnormality is detected, the monitoring operation by the optical sensor 21 under the conditions of T2 and T3 in FIG. 4B is projected as shown in FIG. 5B. Regarding the reflectance of light, the reflectance at each depth is measured as the light gradually penetrates deeply into the Al chelate solution 30a. However, since the amount of dropping is small, such reflectance is lower than in the case of dropping a normal amount. Shows a diagonal attenuation straight line with small attenuation.

In the sensor output corresponding to such a monitoring chart, since the attenuation straight line showing the reflectance does not become lower than the threshold value, that is, the flat output display of the H level is maintained even when the condition of T3 is entered. .

When the check of the dropped amount is completed in this way, the spin coater 10a rotates to drop the dropped Al.
The chelate solution 30a is formed into a thin adhesive film as shown in FIG.

Optical sensor 2 under the conditions of T3 to T4
The monitoring operation of No. 1 is as shown in FIG.
As shown in, A was accumulated before being spin-coated.
As the reflectance of 0% based on the 1 chelate liquid 30a is gradually thinly applied by the spin coater 10a, the reflectance gradually increases. At the time when the adhesive film is formed, A
Since the l-chelate film is formed sufficiently thin, the attenuation of the light projection due to the film thickness can be almost ignored, and the flat chart returns to 100% reflectance.

As shown in FIG. 5A, the sensor output corresponding to such a monitoring chart shows that the increasing straight line showing the increase of the reflectance becomes larger than the threshold value, that is, the situation from T3 to T4. At the time of entering the bottom and the Al chelate film having a predetermined thickness, a flat output display of H level is made.

That is, in the case of normal dropping of the Al chelate solution, the characteristic sensor output display shows the H level in the T1 and T2 regions, the L level in the T3 region, and the H level in the T4 region.

On the other hand, when the drop amount is small, the monitoring operation of the optical sensor 21 under the conditions from T3 to T4 is as shown in FIG.
As shown in (b), the reflectance based on the spread and spread Al chelate solution 30a before spin coating is gradually increased as the spin coater 10a is applied thinly, and the reflectance is sufficiently increased. At the time when the thin adhesive film is formed, the attenuation of the projected light due to the film thickness can be almost ignored, and the flat chart returns to 100% reflectance. However, since the drop amount is small, the increase in the reflectance is smaller than that in the case of the normal drop amount, similarly to the attenuation state of the reflectance.

As shown in FIG. 5 (b), the sensor output corresponding to such a monitoring chart is made in a state where the increase in reflectance is higher than the threshold value, that is, even at the time of entering the state of T3 to T4. A flat output display of H level is maintained. That is, in the case of abnormal dropping of the Al chelate liquid, a characteristic sensor output display showing a flat straight line of H level throughout the entire area of T1, T2, T3, and T4.

As shown in FIG. 3 above, an alarm signal is output to the control unit 26 side of the spin coater 10a in the case of abnormal dropping according to the sensor output corresponding to normal dropping or abnormal dropping of the Al chelate solution. On the basis of the alarm signal, the spin coating of the spin coater 10a is interrupted and other measures are taken.

As described above, according to the present invention, the adequacy of the dropping amount of the Al chelate solution is checked by the change of the reflectance by the optical sensor 21, and the application failure of the Al chelate film due to the insufficient dropping amount of the Al chelate solution is caused. Application defects such as application unevenness can be detected. Therefore, it is possible to avoid defects such as film peeling due to defective adhesion of the PIQ film formed on the wafer using the Al chelate film as an adhesive film.

In the above description, the case where the present invention is applied to the formation of the Al chelate film has been described as an example, but the same can be applied to the case where the photoresist film is formed by the spin coating method as follows. it can.

That is, as shown in FIG. 6, first, in step S110, a wafer is set on the spin chuck 12 of the spin coater 10a. In such a wafer, an SiO ₂ oxide film is formed on a substrate (Si wafer), and a nitride film is formed on the oxide film by a vapor phase epitaxy method.

In step S120, an appropriate amount of photoresist is dropped from the coating nozzle 15 of the spin coater 10a onto the nitride film of the wafer having the above structure supported by the spin chuck 12.

In step S130, light of a safety light wavelength that does not expose the photoresist is projected from the light projecting portion 22 of the optical sensor 21 provided on the side of the coating nozzle 15 toward the dropped photoresist. It The reflected light is received by the light receiving portion 23 of the optical sensor 21, and the reflectance is obtained by the sensor amplifier 24 based on the amount of reflected light.

In step S140, the obtained reflectance is compared with the reflectance (threshold value) previously obtained for an appropriate amount of photoresist. If the reflectance is less than the threshold value, the photo-resist in step S110 is determined. It is determined that the amount of resist dropped is normal.

If it is determined that the amount of the dropped photoresist is appropriate, the spin chuck 12 of the spin coater 10a is rotated at a high speed to deposit the photoresist on the nitride film on the wafer as shown in step S150. It is spread thinly to form a photoresist film having a predetermined thickness.

If it is determined in step S140 that the amount of photoresist dropped is inappropriate, the rotation of the spin coater 10a in step S150 is stopped.

Then, in step S160, the circuit pattern is printed on the photoresist film of the photosensitive resin by exposing it to ultraviolet rays by using a stepper with a predetermined mask.

The unexposed portion or exposed portion of the photoresist film is removed by dissolution with a developer in step S170, and predetermined development is performed.

After the development, in step S180, the remaining photoresist is baked and the remaining photoresist is used as a mask to etch the nitride film and the silicon oxide film with an etching agent.

After the etching, the photoresist is removed by ashing and the wafer is washed. Then, the wafer is put into an oxidation furnace, and a silicon oxide film for element isolation is formed on the surface by using the remaining nitride film as a mask. After that, the nitride film is removed with high temperature phosphoric acid or the like, and the oxide film is removed with a hydrofluoric acid solution to perform cleaning.

After cleaning, a thin silicon dioxide film is formed as a gate insulating film, a polycrystalline silicon film is further deposited thereon, and an N-type conductivity type impurity is added to this polycrystalline silicon film. Further, a gate electrode pattern is processed on the polycrystalline silicon film by photolithography.
Using the gate electrode film thus formed as a mask, arsenic is ion-implanted into the substrate surface through a thin silicon dioxide film to form a pair of N-type regions and source / drain regions.

After that, an interlayer insulating film such as a silicon oxide film is deposited on the entire surface of the wafer by a vapor phase growth method or the like. A contact hole for drawing out an electrode is formed in the interlayer insulating film, an aluminum film to be a wiring is further deposited, and the aluminum film is processed into a desired wiring pattern by photolithography to form a circuit pattern on a Si substrate. Build in.

An Al chelate film is formed on the wafer thus formed as described above, and PIQ is formed on the Al chelate film.
A semiconductor device can be manufactured by forming a protective film such as a film.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the above-described embodiment, the spin coating method has been described as an example, but in the case of judging the applicability of the dropping amount of the film forming material supplied to the film formation target surface, it is possible to use other coating methods. It can be widely applied.

In the above description, the case where the adequacy of the dropping amount is grasped as the reflectance has been described. However, instead of the reflectance, the dropping amount of the dropping amount is determined by using the reflected light amount or another value having a correlation with the reflected light amount. You may make a decision.

In the above description, the reflectance at the proper dropping amount is set as a threshold value, and whether the proper amount is appropriate or not is determined alternatively by comparing the magnitude with the threshold value. However, by grasping the light amount of the reflected light according to the increment of the drop amount, it is possible to determine how much the drop amount is insufficient or how much the drop amount is based on the reflected light amount. You can also

Furthermore, if the correlation between the reflectance and the amount of dropping is grasped in advance, the thickness of the film-forming material at the sensor measurement point can be changed due to the difference in reflectance after a predetermined time has passed after dropping. It is also possible to detect the difference and judge the magnitude of the viscosity of the film forming material from the result. Such a determination can be made because if the viscosity is lower than the specified viscosity, the film-forming material spreads for a certain period of time after dropping, and the thickness of the measurement location of the sensor should be thinner than in the case of the specified time. If the viscosity is high, the thickness will be thick and the reflectance will be small.

In the above description, the case of the Al chelate film and the photoresist film used as the adhesive film of the protective film has been described as an example. However, in addition to this, when the protective film, the insulating film and the like are formed by the coating method. Can also be applied. Further, it is needless to say that the application to the photoresist film can also be applied to the peripheral exposure when the photoresist film is formed on the peripheral portion of the wafer and then the peripheral portion of the wafer is etched by exposure and development.

In the above embodiment, the case where the Al chelate film is formed as the adhesive film material when the PIQ insulating film is formed as the protective film on the wafer surface has been described as an example. Further, as long as the amount of the film forming material before application can be grasped as the fluctuation of the reflectance, it can be widely applied to the film forming materials other than the Al chelate material.

[0087]

The effects obtained by the typical ones of the inventions disclosed in this application will be briefly described as follows.
It is as follows.

That is, when the film is formed by the coating method, the optical sensor determines whether the amount of the film forming material supplied to the film forming surface is appropriate. It is simple and it is possible to manage the dropping of the film forming material at low cost.

At the time of forming a film by the coating method, the optical sensor determines whether the amount of the film forming material supplied to the film forming surface is proper, and therefore, the indirect monitoring based on the abnormality detection of the film forming material supply system. Compared with the method, the film-forming material actually dropped can be directly monitored.

Therefore, by applying the Al chelate film for forming a film by applying the spin coating method,
It is possible to manage the defective application of the chelate film at low cost, prevent the peeling of the protective film due to the defective application of the Al chelate film as the adhesive film, and improve the product reliability of the semiconductor device at low cost. it can.

[Brief description of drawings]

FIG. 1A is a cross-sectional view of a main part when a semiconductor manufacturing apparatus used in a method for manufacturing a semiconductor device according to an embodiment of the present invention is configured as a spin coater, and FIG. 1B is a main part thereof. It is a top view.

FIG. 2 is a main part explanatory view showing an enlarged part surrounded by a circle in FIG.

FIG. 3 is an explanatory diagram showing a flow of judgment of suitability of a dropping amount of a film forming material by an optical sensor.

FIG. 4 (a) shows a check state of reflectance by an optical sensor before dropping an Al chelate solution, and FIG. 4 (b) shows Al.
The chelate solution is dropped, and the light is started to be emitted from the optical sensor to the Al chelate solution, and the check situation in which the reflectance of the returned reflected light is compared with the threshold value is shown. The check condition by the optical sensor in the state where the film is formed is shown.

FIG. 5A is an explanatory diagram showing a monitoring operation chart when the dropping is normal, and FIG. 5B is a monitoring operation chart when the dropping is abnormal.

FIG. 6 is a flow chart showing steps when the present invention is applied to formation of a photoresist film.

[Explanation of symbols] 10 Semiconductor manufacturing equipment 10a spin coater 11 application cups 12 Spin chuck 13 motor 14 rotation axis 15 Coating nozzle 15a discharge port 16 nozzle bracket 21 Optical sensor 22 Projector 22a optical fiber 23 Light receiving part 23a optical fiber 24 sensor amplifier 25 I / O ports 26 Control unit 30 film forming material 30a Al chelate solution S1 step S2 step W wafer

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 21/30 564C F term (reference) 2H025 AA18 AB16 EA05 4D075 AC64 DA08 DC22 EA45 5F046 JA09 JA21 5F058 AA03 AC02 AC10 AF04 AH03

Claims (5)

[Claims] 1. A method of manufacturing a semiconductor device, comprising a step of forming a film by spreading a film forming material supplied to a film forming surface by a coating method, wherein an optical sensor is used to determine whether the supply amount of the film forming material is appropriate. A method of manufacturing a semiconductor device, characterized in that 2. A method for manufacturing a semiconductor device, which comprises a step of forming a film by spreading a film-forming material supplied to a film-forming surface by a coating method, wherein the supply amount of the film-forming material is supplied appropriately. A method for manufacturing a semiconductor device, which is characterized by a change in a reflection amount of light projected onto the film forming material in a state before coating. 3. A method of manufacturing a semiconductor device, comprising a step of forming a film by spreading a film forming material supplied to a film formation surface by a coating method, wherein the film forming material is in a state after coating and before coating. The amount of light reflected to the film-forming material is compared with the reference amount of light projected to the film-forming material in a state before coating after supplying an appropriate amount to determine whether the supply amount of the film-forming material is appropriate. A method for manufacturing a semiconductor device, which comprises determining. 4. A method of manufacturing a semiconductor device, comprising a step of forming a film on a wafer surface via an adhesive film formed by a coating method, wherein the supply amount of the adhesive film material supplied to the wafer surface is Comparison of the amount of light projected onto the adhesive film material in a state before application after application and the reference amount of light projected onto the adhesive film material in a state before application after application of an appropriate amount Then, the adequacy of the supply amount of the adhesive film material is determined, and the method of manufacturing a semiconductor device. 5. A method of manufacturing a semiconductor device, which comprises a step of forming a protective film on a film-forming surface via an adhesive film formed by a spin coating method, wherein the adhesive film material is dropped onto the film-forming surface. The reflection amount of the light projected and reflected before the spin coating is the reflection amount of the light projected and reflected before the spin coating on the adhesive film material that has been supplied in an appropriate amount on the film-forming surface in advance. The method for manufacturing a semiconductor device is characterized in that when the reflection amount is smaller than the reference reflection amount, the supply amount of the adhesive film material is appropriate by comparing with the reference reflection amount.