JPH10296624A - Method and device for affixing wafer to porous surface plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cheap affixing device that can improve its performance and perform adjustment with ease by simplifying semiconductor wafer affixing process. SOLUTION: This device is provided with a vacuum adsorptive disk 6 for adsorbing an affixing porous disk 1 for making vacuum 4 work to a wafer adhering face. A pressure resistant container 7 are attached on the sides of a wafer holding mechanism 11 and vacuum adsorptive disk 6 so that they can be adhered pressed by air pressure to become a pressure container when they approach each other closely. An air heating device 9 for heating and drying a adhering layer 3 is provided. A pressure adjusting device 10 is provided to reduce the pressure of compressed air 5 and give the pressure-reduced compressed air to the air heating device 9. The affixing porous disk 1 is made to lightly contact with the side of the adhering layer 3 of the semiconductor wafer 2 floating due to the jet stream caused by the wafer holding device 11 to pressure bond the wafer 2 by the uniform pressure of the air 5. A pressure switch 8 is provided to control the pressure when pressure bonding the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION In a semiconductor wafer manufacturing process, a semiconductor wafer is attached to a ceramic or Pyrex sticking plate (sticking plate) with an adhesive and mirror-polished (so-called "polishing"). This method is called a wafer mounting method, and the present invention relates to the improvement of the bonding accuracy such as flatness and strength when a semiconductor wafer is bonded to the bonding platen. Hereinafter, the “semiconductor wafer” may be abbreviated to simply a wafer.

[0002]

2. Description of the Related Art A device in which a liquid obtained by dissolving a heat-softening type adhesive in a solvent is thinly and uniformly applied to a non-polished surface of a wafer, dried, and then attached to a heated attachment platen. Sticking device, wax mounter overseas (w
Although there is an apparatus called an ax mounter, the sticking accuracy, that is, the flatness of the adhesive layer formed between the sticking platen and the wafer and the uniform adhesive strength greatly affect the flatness of the wafer to be produced (particularly). Kaisho 63-316451,
Japanese Utility Model Application Laid-Open No. 4-5634). Hereinafter, a state in which the adhesive is applied on the wafer, or a layer formed between the attaching platen and the wafer is referred to as an adhesive layer, and is referred to as an adhesive when its properties and materials are described.

[0003] Fluidity, viscosity and adhesive strength of the dried adhesive greatly change depending on the ratio of the remaining solvent, that is, the state of drying and its temperature. The dried adhesive cannot obtain the adhesive force required for polishing unless it is heated and pressed and pressed against the application platen.

In a conventional apparatus, temporary bonding is performed by a mechanical method, for example, a wafer reversal bonding apparatus or the like that bonds a wafer by a method such as suctioning and holding a wafer with a vacuum suction board and pressing an adhesive surface against a bonding surface plate. There is a process (Japanese Utility Model Application Laid-Open No. 5-4482) and a full-bonding process using a soft and elastic object such as a rubber balloon to press the whole of the wafer onto the attaching platen (Japanese Utility Model Application Laid-Open No. 4-88033). However, in these steps, means have been designed so as not to impair the uniformity of the thickness of the adhesive layer.

[0005] In addition, a solvent remains in the applied adhesive, and the dried state is an important condition for performing high-precision bonding. However, drying is performed by drying and condensing the adhesive layer to a constant state. There is a process. In order to improve the sticking accuracy, it is required that the dried state be as uniform as possible over the entire wafer and a constant degree of dryness before the bonding.

However, in these methods, it is not easy to always obtain a high sticking accuracy which is optimal for polishing. A non-contact distance meter for measuring a distance to a sticking platen surface with which the wafer comes into contact, and the wafer is pushed based on the measurement. Precise control technology to correct the height position was required. In addition, it is difficult to reproduce the same conditions by showing the optimum bonding conditions as numerical values, and iterative trial-and-error while measuring the bonding flatness of the wafer bonded on the bonding surface plate with a measuring device for each device is repeated. I have to make adjustments. In other words, it was not easy to maintain and manage a constant sticking accuracy.

Further, such an apparatus includes various mechanisms, a wafer adhesive baking apparatus having a heating means such as a halogen lamp (Japanese Utility Model Laid-Open No. 7-42132), the wafer reversing and sticking apparatus, the wafer bonding apparatus, and the sticking apparatus. Combination with a non-contact distance meter or the like that measures the thickness and height of the surface plate complicates the configuration and increases the cost, labor, and time required for manufacturing.

Further, in recent years, the demand for flatness of a wafer has been increasingly increased due to the high integration of semiconductor ICs, and the diameter of the wafer itself has been increasing. It will be difficult to produce wafers efficiently at low cost in the future with the current bonding technology.

[0009] At present, various ideas have been devised to improve the sticking accuracy. For example, use is made of a radiant heat from a heating plate in which the non-uniformity of drying caused by drying with a wafer or a wafer sticking method (Japanese Patent Laid-Open No. Hei 7-183261) for removing bubbles entering the adhesive layer and bonding the wafers in a vacuum is improved. Known drying methods are known.

[0010]

The wafer maker does not require precise adjustment and can always manufacture a wafer with a stable flatness, and can also cope with future high integration of IC and increase in diameter of the wafer itself. Is needed. The present invention is a new inexpensive technology that can be implemented at a low cost and that has been invented in order to meet the demands of such wafer manufacturers.
Hereinafter, a description will be given of a problem in the conventional technique.

[0011] In the pasting technology, since the gas is adhered to a surface plate which does not allow gas or the like to permeate at all, there is no escape of gas and remains as air bubbles in the adhesive layer, and there is a problem that the adhesion accuracy is deteriorated. Therefore, a wafer bonding method of bonding wafers in a vacuum (Japanese Patent Application Laid-Open No. 7-183261) was invented, but vacuum cannot be continuously applied to the bonding layer from the start of bonding to the completion of temporary bonding, ie, from the start of temporary bonding to the completion of main bonding. There are drawbacks. That is, since air may enter the adhesive layer before the actual bonding, the problem that air bubbles remain in the adhesive layer is not completely solved.

Further, a conventional bonding technique is a method in which a non-bonded surface side of a wafer is pressed with a stamp or pad such as a rubber balloon or a so-called press head, and the bonded surface is pressed against a bonding platen (see Japanese Utility Model Application Laid-open No. Hei 4-4-1). 88033, JP-A 1-2
16540), there is a process called final bonding in which the entire wafer is attached as flat and as strong as possible, but it is not possible to measure how uniformly and at what pressure this stamp is actually pushing the wafer. It was difficult. Therefore, the adjustment had to rely on an instrument for measuring feeling, experience, or affixed state. Therefore, a lot of time, labor and test wafers are required for starting up and adjusting the apparatus. Also, it has been difficult to always reproduce the same adjustment so that the optimum condition is obtained.

Furthermore, the durability of the rubber stamp itself is not good. Even if the stamp has a defect, many defective products may be produced without any method other than visual inspection. For example, a crack on the surface of the stamp
Since it is impossible to pressurize the wafer on average, defects in the unevenness may occur on all of the product wafers.

If the adhesive layer is not sufficiently dried at the time of the temporary bonding, or if the adhesive strength at the time of the temporary bonding is insufficient due to too much drying or insufficient pressing force, it is necessary to proceed to the next actual bonding. In some cases, the wafer slips on the attachment platen, resulting in equipment failure, loss of operation time, and loss of the wafer.

In the conventional bonding technique, when the surface of the wafer vacuum suction plate to be temporarily bonded and the surface of the bonding surface plate are not sufficiently parallel, or when the pressing force of the wafer vacuum suction plate is excessive, one of the bonding surfaces may be damaged. The portion is excessively pressed and distortion remains in the adhesive layer, and the bonding accuracy is reduced. However, it is difficult to precisely measure and adjust the parallelism between the surface of the wafer vacuum suction disk and the surface of the attaching platen and the pressing force of the vacuum suction disk.
Therefore, in order to adjust the uniform pressing and the pressing itself, it is necessary to rely on an instrument for measuring the feeling, the experience, or the attached state. Therefore, a lot of time, labor and test wafers are required for starting up and adjusting the apparatus. In addition, it has been difficult to always reproduce the same adjustment so that the optimum conditions are obtained.

Further, since the above-mentioned vacuum suction disk is in direct contact with the wafer, if it is repeatedly used in the wafer bonding apparatus, the heat of the dried wafer and the bonding surface plate is accumulated, and the temperature of the wafer itself rises. Therefore, the temperature of the wafer in the vicinity of the suction surface is increased before the application and the adhesive is softened, so that the contact pressure at the moment when the wafer comes into contact with the application surface plate easily causes distortion or damage to the adhesive layer. That is, it is better that the temperature of the adhesive is low until the moment of contact, but this is not the case with the current wafer bonding apparatus.

A conventional wafer reversing and sticking apparatus (Japanese Utility Model Laid-Open No. 5-4)
In 482), since there is no means for uniformly heating or cooling the entire wafer, the vacuum suction disk (chuck plate) must be heated in accordance with the temperature of the heated and dried wafer. However, in this method, since the entire surface of the wafer cannot be heated uniformly, drying of the central portion of the wafer proceeds with time. Therefore, over time, neither an average temperature distribution nor a dry state can be obtained. When a wafer is continuously attached, the temperature of the vacuum suction plate becomes as high as that of the attachment platen, so that the central portion of the wafer tends to be excessively dried.

Wafer bonding apparatus (Japanese Utility Model Application Laid-open No. 63-17256)
1) has a structure in which a heating heater is provided in the pressure head to heat the wafer even from the wafer surface, but this is not the best method for high-precision bonding. Because the pressurization of the wafer is a mechanical method, it is not easy to always press the entire surface of the wafer with a uniform force.

Further, in the conventional bonding technique, there is a mechanism for heating and drying the entire wafer in order to uniformly dry the entire adhesive layer, but it is not easy to dry the wafer appropriately and uniformly. For example, there is a device that adsorbs and holds the center of the wafer and heats and drys the surface coated with adhesive with a halogen lamp in the air. The part tends to be over-dried due to the constantly higher temperature than the periphery. Also in the wafer reversing and sticking apparatus, the central portion of the wafer is particularly dried by the heat of the heated chuck plate.

In some cases, it is not always possible to say that the wafer or the attachment surface plate to be attached is in an optimum attachment state.
For example, when the thickness of the wafer is not uniform. If the apparatus for thin wafers is adjusted to increase the pressure for temporary bonding, the thick wafers will be excessively pressed against the bonding platen, and the bonding accuracy will deteriorate.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to easily adjust an adhesive drying and bonding process and reproduce optimum conditions. That is, the mechanism is realized by a simple and easy-to-control mechanism that can be easily removed, thereby reducing the failure of the apparatus and stabilizing the sticking accuracy. Further, it is possible to cope with mass production of large-diameter wafers with higher accuracy than the current situation in which demand is expected to increase in the future.

[0022]

In order to achieve the above-mentioned object, in the sticking mechanism of the present invention, the sticking platen is made of a porous material, and a vacuum suction plate for sucking the non-adhesive surface side is provided.
For the wafer to be attached, the compressed gas is depressurized to a constant pressure and a gas jet heated to a constant temperature is blown vertically toward the center of the non-adhesive surface to keep it constant without contact with the wafer surface. Provide a mechanism that can be held at a distance. Further, one of the vacuum suction disk and the wafer holding mechanism is fixed to a mechanism (not shown in the drawing) for vertically moving to a position where the bonding platen and the wafer can be pressed against each other. further,
Each of the vacuum suction disks and the wafer holding mechanism is fixedly provided with a pressure-resistant container (covered object) so as to form a single pressure container when it is moved to a position where pressure contact can be made.

When the wafer holding mechanism is turned downward in the above, a gas flow for holding the wafer at a certain distance is generated on the wafer surface by using Bernoulli's theorem.

In the above wafer holding mechanism, it is possible to apply distortion to the wafer by changing the flow velocity of the gas flowing through the central portion and the peripheral portion of the wafer. In order to adjust the pressure at which the layers are pressed, a pressure regulator for reducing the pressure of the compressed gas and supplying it at a constant pressure is provided.

Further, a pressure switch for minute pressure is provided in order to detect the pressure when the bonding platen is pressed against the wafer and to control the tightness of the pressure vessel.

Further, a gas heater is used for heating the gas to be blown as described above, and it is assumed that the temperature can be controlled to be constant according to an external temperature setting.

Next, the means will be described by taking as an example a case of pasting to a conventional pasting platen. First, the pressure of the compressed gas is reduced to a constant pressure for the wafer to be bonded, the temperature is controlled, and the flow rate is adjusted by a flow rate control valve or a flow rate controller controlled by an external electric signal. A mechanism is provided in which the jet is sprayed toward the center of the non-adhesive surface and the adhesive surface is directed downward using the Bernoulli's theorem, so that the device can be held in contact with the surface of the wafer. A mechanism for vertically moving the disk-shaped wafer holding mechanism vertically to a position where the wafer is pressed against the bonding platen (not shown in the figure).
To be fixed. A pressure regulator is used in the same manner as described above for decompression and pressure regulation of the compressed gas.

However, here, instead of a simple gas heater, a device capable of switching between a low temperature and a high temperature, and controlling the supply and stop of the gas itself from the outside (hereinafter, temporarily referred to as a gas heating / cooling supply device) is used.

In order to control the pressure by reading the amount of change in the gas pressure at the center of the wafer instead of the pressure switch, the pressure transducer converts the pressure into an electric signal (current or voltage) and outputs the signal. Sa (transdu
cer).

Further, in order to equalize the gas pressure when the wafer is pressed against the bonding platen over the entire wafer surface, the gas can be blown from the outer peripheral portion of the wafer. Therefore, an annular gas blowing groove is provided along the outer periphery of the wafer holding mechanism, and an electromagnetic valve is provided to control gas supply to the annular gas blowing groove. This solenoid valve is used for opening and closing the gas flow path after the flow rate adjustment. That is, the pipe is formed so as to have the same circuit as the line blown to the center of the wafer.

Further, the gas outlet groove in the outer peripheral portion of the wafer is connected to a vacuum and connected to a pipe so as to be able to suck the gas, thereby acting as a force for sucking the wafer. A flow regulating valve and a solenoid valve are provided to control supply and stop to the groove in the outer peripheral portion.

[0032]

Embodiments of the present invention will be described with reference to the drawings. A semiconductor wafer 2 having a 20 mm-thick disk-shaped whole lamination plate 1 heated to about 90 ° C. and having an adhesive layer 3 uniformly coated with a liquid adhesive to a thickness of about 0.003 mm. Will be described in order. Here, an adhesive that softens at about 70 ° C. or more during drying is used.

The compressed gas 5 is applied vertically from below toward the center of the semiconductor wafer 2 with the adhesive layer 3 facing upward.
The pressure is reduced to 0, the wafer is heated to about 70 ° C. through the gas heater 9, and the wafer is floated horizontally by blowing the gas jet. After the elapse of the time set as the drying time, the heating of the gas is stopped and the following steps are started.

The bonding platen 1 is horizontally held by suction with the vacuum suction plate 6, and is vertically lowered onto the semiconductor wafer 2 so that the bonding surfaces thereof are parallel to each other. At this time, the upper and lower pressure containers 7 are simultaneously brought close to a position where one pressure container including the semiconductor wafer 2 and the attaching platen 1 is formed.

When the pressure switch 8 reaches 0.06 kg / cm ² , the descent is stopped, the state is maintained for 3 seconds, and then the position of the pressure plate 8 is raised to a position where the platen 1 can be taken out.

[0036]

[Other Embodiments] The attaching platen 1, the semiconductor wafer 2, and the entire attaching mechanism described in "Embodiments of the Invention" can be turned upside down. "Embodiments of the invention"
The differences from those described above will be described below. Here, the description will be made assuming that the drawings referred to in the “embodiment of the invention” are rotated vertically.

The bonding surface of the semiconductor wafer 2 is held horizontally downward by a non-contact holding method applying Bernoulli's theorem, which is often used for transporting a plate-like substrate such as a semiconductor wafer. In this case, a gas flow which spreads uniformly from the central portion of the non-adhesive surface of the semiconductor wafer 2 to the outer peripheral portion is created to hold the gas. As a specific method, this is realized by providing a gas outlet 33 having a shape shown in FIG.

The attaching platen 1 held horizontally is fixed, and the semiconductor wafer 2 is moved and lowered vertically.

In the embodiment shown in FIGS. 4 and 5, a polishing plate made of alumina which is capable of evenly attaching a plurality of wafers to one outer periphery thereof, which is currently most frequently used as the attachment surface plate 17, is shown. Using The sticking platen 17 is heated to about 60 ° C. and placed on a horizontal index table 29 with the sticking surface facing upward.

Semiconductor wafer 18 coated with adhesive uniformly
Is held by the wafer holding mechanism 23 applying the Bernoulli's theorem, which has three slip prevention pins evenly along the outer periphery of the wafer, with the bonding surface facing down. Therefore, the pressure of the gas blown to the center of the semiconductor wafer 18 is adjusted by the flow control valve 27 so that the wafer does not drop. Here, the adhesive layer 19 of the semiconductor wafer 18 is used.
The following operations and operations will be sequentially described on the assumption that uniform drying has been completed on the entire wafer.

First, the temperature of the gas output from the gas heating / cooling supply device 21 is switched to a low temperature of 5 ° C. Then, after the semiconductor wafer 18 is cooled, the semiconductor wafer 18 is transferred to the attachment plate 17 while the semiconductor wafer 18 is kept horizontal. The descent is started. Immediately after the descent is started, the value of the pressure transducer 26 is read and temporarily stored as an initial value a. This reading is continued while being lowered and compared with the initial value a.
When the pressure change that has been verified at the time of contact with the attachment surface plate 17 is found, the next operation is started.

The temperature of the gas output from the gas heating / cooling supply device 21 is increased to 130 ° C. At the same time, the solenoid valve 28 is opened (ON).

Then, while reading the value of the pressure transducer 26, the pressure is further lowered, and when the variation compared with the initial value a exceeds 0.3 kg / cm ² , the lowering is stopped immediately. Therefore, this state is maintained for a sufficient and necessary time for the bonding that has been verified in advance.

Thereafter, the solenoid valve 28 is closed (off), the gas heating / cooling supply unit 21 stops heating and supply of gas, and at the same time, the wafer holding mechanism 23 is raised to the initial position before lowering. Finally, the index table 29 is turned to rotate the sticking platen to the next wafer sticking position. By repeating the above operation, a plurality of wafers are pasted on one pasting platen.

In the embodiment shown in FIG. 4 and FIG. 5, an embodiment in which the piping system of FIG. 4 is changed as shown in FIG. 6 will be considered.
In this case, the flow control valves 27 and 36 are adjusted so that the semiconductor wafer 18 is held without contact with the wafer surface without falling. The supply and stop of the vacuum to the outer peripheral portion of the wafer are controlled by a solenoid valve 37.
7, the solenoid valve 37 is opened while the wafer is suctioned and held as shown in the time chart of FIG. The other operations and operations are the same as those described above, and will not be described.

[0046]

Since the present invention is configured as described above, the following effects can be obtained.

When the bonding method according to claim 4 or claim 10 is used, the semiconductor wafers 2 and 18 can be mounted on the pressure regulators 10 and 2.
2 or by a low pressure gas jet depressurized by the flow control valve 27, the contact pressure at the time of bonding is reduced by adjusting the gas pressure as compared with the above-mentioned conventional mechanical method. Even if the parallelism between the wafer holding mechanism and the attaching platen is somewhat poor, the force pressing the wafer surface due to the nature of the fluid is averaged. Therefore, scratches and distortion remaining in the adhesive layer can be reduced. In addition, even if there is some error or variation in the thickness of the wafer to be attached or the thickness of the attachment surface plate, they can be contacted with almost the same force. Also, such devices are easier to adjust than conventional devices. They are,
The method as shown in FIGS. 4 and 5 has the same effect on the conventional pasting platen.

When the wafer is held with the bonding surface facing down as in the embodiment shown in FIGS.
The method of claim 4, in which the vacuum acts as a force for lifting the wafer and increases the flow velocity of the gas flowing on the wafer surface, the method of holding the wafer by simply blowing a gas jet to the center of the wafer. Compared with the method, this method is also an effective means for holding a compound semiconductor wafer having a relatively heavy weight per unit area.

According to the bonding method of the sixth aspect, the gas jet heated to a certain temperature is applied to the semiconductor wafer 2,
It is sprayed on the non-adhesive surface 18 and has no heat conduction from the suction plate as compared with the conventional vacuum suction method, so that the entire adhesive layers 3 and 19 can be maintained at a uniform and constant temperature before bonding before bonding. Therefore, a constant and uniform dry state can be always obtained. In addition, the gas temperature can be switched to a low temperature so that the drying does not exceed a certain level, and the application can be waited for, and the control can be simplified and stabilized as compared with the conventional method. This is a new method that can improve the problems of the conventional drying method.

Further, when the bonding method of claim 5 is used, the pressure difference between the gas at the center and the gas at the outer periphery caused by the difference in the flow velocity at which the gas jet flows on the wafer surface, that is, the Bernoulli's theorem, is used. By applying a warp distortion to 18 itself and starting bonding from the center of the bonding surface to the outer periphery, air or a solvent remaining in the bonding layer is heated, and the vaporized gas can escape to the outside. Thus, air bubbles remaining in the adhesive layer can be reduced. Vacuum suction machine with a slightly convex wafer
In general, this is a new method that replaces the conventional method in which a wafer having a convex shape of about 0.03 mm is directly sucked and held to deform the wafer. According to this method, the gas pressure impinging on the wafer surface can be changed by adjusting the pressure regulators 10 and 22 and the flow rate control valve 27, and the distortion of the wafer can be easily adjusted.

Further, when the bonding method according to claim 11 is used, that is, by blowing a gas to the central portion of the wafer and sucking it from the peripheral portion, the central portion of the wafer has a positive pressure and the peripheral portion has a negative pressure. In the same manner as in the bonding method of the fifth aspect, the semiconductor wafer 18 is bonded by giving a warp distortion. In this case, the vacuum acts as a force for attracting the peripheral portion of the wafer, and the flow rate of the gas flowing on the peripheral surface of the wafer is increased. The adjustment range of the wafer distortion can be widened. Therefore, it is possible to cope with a thick wafer having high rigidity.

[0052] Further, the sticking platen according to claim 1 is used.
When the bonding method is used, the bonding platen 1 itself is porous so that gas such as air can pass therethrough. Residual air bubbles and the like are removed, and the pressure of the vacuum 4 acts uniformly on the entire adhesive layer 3 and continuously acts from the contact between the wafer and the attaching platen to the completion of pressurization. As a result, it is possible to obtain a flat and uniform strength bonding state with less bubbles and distortion over the entire wafer as compared with the conventional method.

Conventionally, a temporary bonding step called temporary bonding is performed so that a wafer does not move on a bonding platen, and a bonding state suitable for a polishing step called final bonding is performed. That is, the necessary bonding accuracy and bonding strength are reduced. However, if the bonding method according to any one of claims 3 and 4 or 10 is used, the temporary bonding and the final bonding can be performed in one step, and the problem of wafer slip can be solved and the bonding processing can be performed. It is possible to improve the efficiency of the apparatus and reduce the cost for manufacturing and maintaining the apparatus.

Conventionally, the whole non-adhesive surface of the wafer is pressed with an object called a stamp and pressed against the attaching platen. However, when the attaching method of claim 3 is used, an object such as a stamp is not used. Utilizing the pressure of the compressed gas itself, the entire wafer can be pushed with the uniform force. Bonding can be performed by this uniform force without leaving distortion in the adhesive layer. This also reduces the adjustment effort and time.

Further, according to the bonding method of the ninth aspect, the pressure exerted on the non-bonded surface of the wafer by the pressure switch 8 or the pressure transducer 26 can be accurately detected by an electric signal (current or voltage). The apparatus can be set and controlled in advance so that the conditions can be estimated and optimized. This means that the wafer can always be bonded with an accurate pressing force. Therefore, a device using this method is easier to adjust than a conventional device. Also, even if there is some error or variation in the thickness of the wafer to be bonded or the thickness of the bonding platen, it can be pressed with the same force. This method is also effective for a conventional attachment platen in which a large number of wafers are attached to one sheet as in the embodiment shown in FIGS. There is no means for accurately measuring and controlling this pressing force in a conventional wafer reversing and sticking apparatus (Japanese Utility Model Laid-Open No. 5-4482) and a wafer bonding apparatus (Japanese Utility Model Application Laid-Open No. 4-88033).

Further, by using the bonding method according to the sixth aspect, the temperature distribution of the entire wafer can be made uniform as compared with the conventional method, and the dry state and the temperature of the adhesive layer, which are important elements of the wafer bonding, can be obtained. Can be attached to the entire surface of the wafer under the same conditions. In this respect, this method is superior to the conventional attaching method.

Further, the higher the temperature of the adhesive layer, the lower its viscosity. Therefore, when the adhesive layer is brought into contact with the platen at a temperature higher than the softening point, the adhesive layer is distorted or damaged by a partial contact pressure. Easy to leave. By using the bonding method of claim 7, the temperature of the whole wafer can be controlled to a low temperature by using a gas as a medium, and the problem of the viscosity decrease at this high temperature can be improved while suppressing the influence of the radiation heat of the bonding platen. In the pasting means, there was no method for forcibly reducing the temperature of the wafer.

Further, by using the bonding method according to the eighth aspect, the bonding layer can be uniformly heated from the wafer side to the required bonding temperature over the entire wafer by using the heated gas as a medium, and the temperature of the bonding plate can be reduced. It becomes possible. If a wafer bonding apparatus using this method is manufactured, the equipment and ability to heat and cool the bonding platen can be simplified. Conventionally, there has been a method of heating from the wafer side, but has various difficulties as described above.

Further, even if a current wafer pasting apparatus or an adhesive is used simply by changing the current pasting surface plate currently used by the wafer maker to the pasting surface plate of claim 13 and using the same. The problem of air bubbles remaining in the adhesive layer is that gas and air generated from the adhesive are released to the surface plate, so that large air bubbles do not remain and can be improved. Further, since a dry-curable adhesive also generates gas at the time of drying, a problem of air bubbles occurs in the current bonding platen. Even if the adhesive plate is made of a porous material or a material with the property of releasing gas from the bonding surface, it can be pressed while the adhesive has sufficient adhesive strength, that is, the adhesive is pressed when the adhesive is not dried. Even so, the gas generated from the adhesive can be escaped, and the control can be stabilized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of attaching a wafer to a porous platen of the present invention.

FIG. 2 is a perspective view of a main part of the wafer holding mechanism of the present invention.

FIG. 3 is a longitudinal sectional view showing a configuration of a shift prevention pin of the present invention.

FIG. 4 is a piping system diagram of another embodiment of the present invention using a current attachment surface plate.

FIG. 5 is a vertical sectional view of a main part of another embodiment of the present invention using a current attachment surface plate.

FIG. 6 is another piping system diagram of another embodiment of the present invention using a current attachment surface plate.

FIG. 7 is a time chart of another embodiment of the present invention using a current attachment surface plate.

[Explanation of symbols]

 1, 17 Sticking surface plate 2, 18 Semiconductor wafer 3, 19 Adhesive layer 4, 35 Vacuum 5, 20 Compressed gas 6 Vacuum suction plate 7, 12 Pressure vessel 8 Pressure switch 9 Gas heater 10, 22 Pressure regulator 11, 23 Wafer holding mechanism 13, 24 Pin for preventing slippage 14, 25 Wafer holding board 15 Spring cover 16 Spring 21 Gas heating / cooling supply device 26 Pressure transducer 27, 36 Flow rate regulating valve 28, 37 Solenoid valve 29 Rotary table Reference Signs List 30 Wafer outer peripheral gas supply line 31 Wafer central gas supply line 32 Wafer outer peripheral gas passage (duct) 33 Wafer central gas outlet 34 Wafer outer peripheral gas outlet groove

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[Procedure amendment]

[Submission date] April 8, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

Wafer bonding apparatus (Japanese Utility Model Application Laid-open No. 63-17256)
1) has a structure in which a heating heater is provided in the pressurizing head and heating is performed from the wafer surface, but it cannot be said that it is the best method for high-precision bonding. This is because the pressure of the wafer are both a mechanical method, it is not easy to always press the entire surface of the wafer with a uniform force.

Claims (12)

[Claims] 1. A method of attaching a semiconductor wafer to a porous attachment surface plate (1) which allows a gas to permeate a part or the whole of the application surface plate but does not allow a high-viscosity adhesive to permeate. 2. A method and an apparatus for attaching a semiconductor wafer (2) while suctioning the adhesive surface side of the semiconductor wafer (2) with a vacuum (4) through the attaching surface plate (1) of claim 1. 3. A method and apparatus for bonding a non-adhesive surface of a semiconductor wafer (2) using a force exerted on the semiconductor wafer while the gas is applied to the non-bonded surface with a constant pressure. 4. A method and apparatus for blowing a gas jet onto a non-adhesive surface of a semiconductor wafer (2) and holding the semiconductor wafer (2) in a non-contact manner with the surface of the semiconductor wafer. 5. A method in which a gas jet is blown to the center of a non-adhesive surface of a semiconductor wafer (2), and the semiconductor wafer (2) is distorted by utilizing a pressure difference generated between the center and the periphery thereof, and is attached to an attaching platen. And equipment. 6. A gas at a controlled temperature is blown onto the non-bonded surface side of the semiconductor wafer (2) so as to be kept in non-contact with the semiconductor wafer surface, thereby always reducing the temperature difference of the entire semiconductor wafer before bonding. A method and apparatus for attaching the adhesive layer (3) while keeping the drying state uniform and constant. 7. An adhesive layer (19) for a semiconductor wafer (18).
A method and an apparatus for bonding in which the temperature difference between the entire adhesive layer (19) and the temperature is kept low when the substrate is brought into contact with the bonding plate (17). 8. A platen (1) for attaching a semiconductor wafer (18).
At the time of pressure contact with 7), a heating gas whose temperature is controlled is blown to the non-bonding surface side of the semiconductor wafer (18), and the entire bonding layer (19) is heated by the heat of the gas to raise the temperature to a temperature suitable for bonding. A method and an apparatus for attaching to an attaching surface plate (17). 9. A pressure switch (8) or a pressure transducer (26) capable of converting pressure into an electric signal and extracting the same to detect or estimate the gas pressure exerted on the non-adhesive surface side of the semiconductor wafer (2, 18). A method and apparatus for attaching to the attachment surface plate (1, 17) while controlling the pressure. 10. Gas blowing and suction are simultaneously applied to the semiconductor wafer (18), and the force exerted by the positive and negative gas pressures on the wafer surface is used to make the semiconductor wafer (1).
8) A method and apparatus for holding and attaching the surface without contact. 11. The semiconductor wafer (1) according to the method of claim 10,
8) A method and an apparatus for applying a strain to the plate and bonding the plate to the platen. 12. A gas such as a solvent which is entirely or partially porous according to claim 1, or a gas such as a solvent generated from the adhesive layer (3), or a gas such as air remaining on the adhesive layer (3) at the time of sticking. Attached surface plate (1) that has the property of absorbing and letting go.