KR20090107919A - Manufacture method of bonding substrate - Google Patents

Abstract

PURPOSE: A manufacturing method of a bonding substrate is provided to efficiently exhaust a gas or a foreign material which exists in a bonding interface. CONSTITUTION: An ion injection layer(11) is formed by injecting a hydrogen ion or a rare gas ion on a surface of a first substrate(10) which is a semiconductor substrate. A surface activation process is performed in one side or both sides of an ion-injected surface(12) of the first substrate and a bonded surface(22) of a second substrate(20). The first substrate is separated from the ion injection layer, and is thinned. A bonding substrate(30) having a thin film is manufactured on the second substrate.

Description

Manufacturing method of a bonded substrate {MANUFACTURE METHOD OF BONDING SUBSTRATE}

The present invention relates to a method for producing a bonded substrate.

In order to further improve the performance of semiconductor devices, silicon on insulator (SOI) substrates have recently attracted attention. In addition, a silicon on quartz (SOQ) substrate, a silicon on sapphire (SOS) substrate, and the like, in which the support substrate (handle substrate) is not silicon, are also used in the fields of TFT-LCD, high frequency (RF) device and the like, respectively.

There are several methods for producing such bonded substrates, but the Smartcut method (registered trademark) is a typical example. This was implanted with hydrogen ions into a single crystal silicon substrate (a donor substrate (hereinafter referred to as a first substrate)) on which an oxide film was formed, and bonded to a support substrate (called a handle substrate (hereafter referred to as a second substrate)). Thereafter, the substrate is heated to around 500 ° C, the silicon substrate is peeled off along the hydrogen ion implantation interface, and the single crystal silicon thin film is transferred to the handle substrate. At this time, a microcavity of hydrogen, called a microcavity, is formed at the hydrogen injection interface, thereby enabling peeling at the interface. Then, in order to raise the bond strength of a single crystal silicon thin film and a handle substrate, it is the method of performing final surface treatment (CMP, heat processing etc.) after heat-processing at high temperature 1000 degreeC or more (for example, patent document 1, patent document). 2 or Non-Patent Document 1).

On the other hand, in the SiGen method, before bonding a silicon substrate in which hydrogen ions or the like is injected to a bonding surface and a substrate of a silicon substrate or another material, plasma treatment of both or one surface of the bonding surface of these substrates is performed to activate the surface. It is a method of joining two substrates in a state, performing a heat treatment at a low temperature such as 350 ° C. to increase the bonding strength, and then mechanically peeling at normal temperature to obtain a bonded SOI substrate (see, for example, Patent Documents 3 to 5). ).

The difference between these two methods lies mainly in the peeling process of the silicon thin film. The Smartcut method requires processing at a high temperature for peeling the silicon thin film, but the SiGen method is capable of peeling at normal temperature.

In particular, in the case of manufacturing a bonded substrate by bonding a semiconductor substrate such as a silicon substrate to another material substrate, a difference in thermal expansion rate or inherent heat resistance temperature is generated between dissimilar materials, which causes cracks or local cracks in the substrate. Since this tends to occur, it is preferable to carry out the steps from the low temperature to the peeling treatment as much as possible. For this reason, it is thought that the SiGen method which can peel at low temperature is suitable as a manufacturing method of the bonded substrate by joining a heterogeneous material substrate.

By the way, in the manufacturing method of the bonding board | substrate which concerns on these bonding methods, such as these, the foreign material and gas which entered into the bonding interface may produce the defect which a semiconductor layer like a void is missing. Such defects, such as voids, are obstacles in device fabrication and are required to be reduced as much as possible. This void is generated because the bonding surface cannot be brought into close contact with the foreign matter or the like, and the semiconductor layer of the portion is not transferred at the time of peeling. In order to prevent the generation of such voids, the cleanliness of the substrate before bonding and the cleanliness of the bonding environment are important, and the cleanliness of the atmosphere to be cleaned or bonded immediately before bonding is maintained at a high level.

However, even if the cleanliness of the substrate before bonding and the cleanliness of the bonding environment are maintained high, there is a problem that voids are particularly likely to occur at the bonding end of the substrate. Moreover, in order to prevent the void at this junction terminal part, further cleaning is required, but there existed a problem that enormous cost and labor cost were needed.

[Patent Document 1] Japanese Patent No. 3048201

[Patent Document 2] Japanese Patent Application Laid-Open No. 11-145438

[Patent Document 3] US Patent No. 6263941

[Patent Document 4] US Patent No. 6513564

[Patent Document 5] US Patent No. 6582999

[Non-Patent Document 1] A. J. Auberton-Herve et al., "SMART CUT TECHNOLOGY: INDUSTRIAL STATUS of SOI WAFER PRODUCTION and NEW MATERIAL DEVELOPMENTS" (Electrochemical Society Proceedings Volume 99-3 (1999) p.93-106)

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and an object thereof is to provide a method for producing a bonded substrate having a good thin film on the entire surface of the substrate, particularly near the bonded end portion.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is a method of bonding a first substrate and a second substrate, thinning the first substrate, and manufacturing a bonded substrate having a thin film on the second substrate. Forming an ion implantation layer by implanting hydrogen ions or rare gas ions or both thereof from the surface of the first substrate as a semiconductor substrate, and the ion implanted surface of the first substrate and the second substrate In the step of performing a surface activation treatment on at least one surface of the surface to be bonded, and the surface on which the ion-implanted surface of the first substrate and the surface of the second substrate are bonded, the humidity is 30% or less and / or the moisture content is 6 g. A thin film on the second substrate by a bonding step of bonding in an atmosphere of not more than / m 3 and a peeling step of thinning the first substrate by separating the first substrate from the ion implantation layer. There is provided a method for producing a bonded substrate, wherein the bonded substrate having the same is produced (claim 1).

Including such a process, when the bonding method of the bonding board | substrate which joins the 1st board | substrate and the 2nd board | substrate in the atmosphere whose humidity is 30% or less and / or the moisture content is 6 g / m <3> or less is used, By lowering the humidity (reducing the amount of water), the propagation speed of the close contact portion at the time of joining can be slowed. Therefore, the gas and the micro foreign matter which exist in a joining interface can be discharged efficiently. Thereby, since a deposit can be prevented from being concentrated and sealed in a junction end part, the joining board which prevents generation | occurrence | production of a void in a junction end part can be performed.

In this case, the first substrate can be any one of a single crystal silicon substrate, a single crystal silicon substrate having an oxide film formed on its surface, and a compound semiconductor substrate (claim 2).

According to the present invention, it is possible to more reliably produce a high quality bonded substrate, such as an SOI substrate, having a good silicon thin film which is particularly required in recent years.

Moreover, according to this invention, not only a silicon thin film but also the bonded substrate which has a favorable thin film which consists of compound semiconductors, such as GaN, can be manufactured more reliably.

Moreover, in the manufacturing method of the bonded substrate of this invention, the said 2nd board | substrate is an oxide film on a quartz board | substrate, a sapphire (alumina) board | substrate, a SiC board | substrate, a borosilicate glass board | substrate, a crystallized glass substrate, an aluminum nitride substrate, a single crystal silicon substrate, and the surface. One of the formed single crystal silicon substrates and SiGe substrates can be used (claim 3).

The 2nd board | substrate used by the bonded substrate of this invention can be suitably selected from these according to the objective of the semiconductor device to manufacture.

Moreover, in the manufacturing method of the bonding board | substrate of this invention, after the said bonding process, the heat processing process of heat-processing the said bonded board | substrate at 100 degreeC-400 degreeC can be performed, and the said peeling process can be performed after that (claim 4). .

Thus, after joining a 1st board | substrate and a 2nd board | substrate, the bonding strength of a 1st board | substrate and a 2nd board | substrate can further be improved by heat-processing the joined board | substrate at 100 degreeC-400 degreeC. In particular, when the heat treatment temperature is 100 ° C. to 300 ° C., even when the substrates of different materials are bonded, the possibility of thermal distortion, cracking or peeling due to the difference in the thermal expansion coefficient can be further reduced. On the other hand, as in the case where both the first substrate and the second substrate are made of a silicon substrate, in the case of bonding the same material, the heat treatment can be performed at a temperature up to 400 ° C, and the bonding strength can be further increased.

Moreover, in the manufacturing method of the bonded substrate of this invention, it is preferable to perform the said surface activation process by a plasma process (claim 5).

In this way, when the surface activation treatment is performed by plasma treatment, the surface on which the surface activation treatment of the substrate has been performed is activated due to an increase in the OH group. Therefore, in this state, when the ion-implanted surface of the first substrate and the surface to be bonded to the second substrate are brought into close contact, the substrates can be more firmly bonded by hydrogen bonding or the like.

Moreover, in the manufacturing method of the bonded substrate of this invention, even if plasma processing is performed as surface activation treatment in this way, the void in a junction terminal part can be suppressed.

Moreover, in the manufacturing method of the bonded substrate of this invention, the external shock is provided from the one end of the said 1st board | substrate, and the external impact is given to the space | interval in the said ion implantation layer of the said 1st board | substrate in the said peeling process. It is preferable to perform by cleavage which progresses from one end to the other end (claim 6).

Thus, when the separation in the ion implantation layer of the 1st board | substrate in a peeling process is performed by cleavage which gives an external shock from one end of a 1st board | substrate, and advances toward the other end from the one which gave the said external shock, Since cleavage occurs in one direction, it is relatively easy to control the cleavage, and a thin film with high film thickness uniformity can be obtained.

As explained above, according to the manufacturing method of the bonding board | substrate of this invention, the propagation speed of the contact | adherence part at the time of joining can be slowed by making the humidity of the atmosphere at the time of joining low (reduce moisture content). Therefore, the gas and the micro foreign matter which exist in a joining interface can be discharged efficiently. As a result, since deposits can be prevented from being concentrated and sealed at the bonding end portion, it is possible to prevent the occurrence of voids at the bonding end portion and to manufacture the bonded substrate.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

As described above, in the conventional method for producing a bonded substrate, even if the cleanliness of the substrate before bonding and the cleanliness of the bonding environment are kept high, there is a problem that voids are particularly likely to occur at the bonding end portion of the substrate. Moreover, in order to prevent the void at this junction terminal part, further cleaning is required, but there existed a problem of enormous cost and labor cost.

The present inventors examined as follows the cause which tends to generate | occur | produce a void especially in a junction terminal part in this way.

Bonding is performed by bringing a part into close contact in the state which superposed | polymerized two board | substrates. Since the space | interval of the board | substrate adhere | attaches narrowly, it adheres spontaneously, and the range propagates toward the other from the junction start part. The aspect of the propagation of the contact | adherence part around this junction start part is shown typically in FIG. At the tip of the propagation of the close contact portion, the gas and the fine foreign matter present at the joining interface are extruded, and these are wiped out. Large foreign objects cannot move at the time of joining and remain in place.

Even when the substrate is washed before bonding, gas or a small foreign matter present in the atmosphere after washing, the atmosphere of the substrate storage portion, or the bonding atmosphere is slightly attached to the surface of the substrate. Activating the substrate surface prior to bonding makes it easier to adsorb these. This barely attached substance is concentrated by moving a bonding interface with expansion of a contact part at the time of joining. This concentrated deposit appears innumerable voids at the junction ends.

In order to reduce the generation | occurrence | production of the void of this junction terminal part, the present inventors further examined and experimented. As a result, it was found that the generation of voids at the end of the joint can be reduced by reducing the amount of moisture in the atmosphere at the time of joining (that is, lowering the humidity).

This can be explained by reducing the amount of moisture in the atmosphere gas at the time of joining, thereby slowing the propagation speed of the contact portion and efficiently discharging the concentrated deposit out from the joining interface.

The present inventors measured the relationship between the amount of moisture (humidity) in the atmosphere gas at the time of joining, and the time required for joining. The result is shown in FIG. 3 about what was measured at the temperature of 20 degreeC.

As can be seen from FIG. 3, the larger the amount of moisture in the atmosphere (the higher the humidity), the shorter the bonding time. That is, the joining speed is fast, and the propagation of the tight part is also fast.

Conventionally, the humidity is controlled to about 45% to 65% in order to prevent static electricity for the purpose of reducing the deposits on the substrate surface and the like. In addition, in Japanese Unexamined Patent Publication No. 2007-141946, for example, the humidity is set to 46% to 60% in terms of 25 ° C with respect to the atmosphere of the cleaning device and the clean room.

Depending on the amount of moisture (humidity) in the atmosphere at the time of joining, the aspect of the propagation of the close contact portion near the joining terminal portion varies.

The mode of the propagation of the close contact portion near the junction end is schematically illustrated in FIG. 1. In FIG. 1A, when the moisture content is small, that is, when the humidity is low (in the present invention), FIG. 1B illustrates when the moisture content is high, that is, when the humidity is high (conventional) have. As shown in Fig. 1 (b), in the case of high humidity as in the prior art, since the speed of propagation of the contact portion is fast and the contact portion also propagates to the outer circumference portion, there is also the propagation of the contact portion from the outer circumference portion at the joining end portion. The part to be swept away becomes narrow and sealing of the attachment portion occurs. On the other hand, as shown in Fig. 1 (a), in the case of low humidity, the propagation speed of the close contact portion is slow, and there is no influence of the propagation of the close contact portion from the outer circumference, thereby securing a sweep-out portion where the deposit is swept away. It is possible to efficiently remove the concentrated deposits.

MEANS TO SOLVE THE PROBLEM In order to reduce the void of the said junction terminal part efficiently enough, the present inventors should make the specific numerical value of a moisture content (humidity) make 30% or less of humidity and / or 6 g / m <3> or less of moisture content. The present invention was completed.

EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of this invention is described with reference to drawings, this invention is not limited to these.

4 is a method of manufacturing a bonded substrate to which the present invention can be applied.

First, as shown to Fig.4 (a), the 1st board | substrate 10 which is a semiconductor substrate, and the 2nd board | substrate 20 are prepared (process a).

At this time, the first substrate 10 may be a single crystal silicon substrate, and in particular, may be a single crystal silicon substrate having an oxide film formed on its surface. When these materials are selected as the first substrate, a bonded substrate having a silicon thin film can be produced. Use of a single crystal silicon substrate having an oxide film formed on its surface is convenient for producing an SOI substrate. In addition, in order to manufacture the bonded substrate which has compound semiconductor thin films, such as GaN, instead of a silicon thin film, the 1st board | substrate 10 can also be made into compound semiconductor substrates, such as GaN.

Further, the second substrate 20 may be an insulating substrate of any one of a quartz substrate, a sapphire (alumina) substrate, a SiC substrate, a borosilicate glass substrate, a crystallized glass substrate, and an aluminum nitride substrate, or a single crystal silicon substrate, It can also be made into any of the single-crystal silicon substrate and SiGe substrate which formed the oxide film in the surface. What is necessary is just to select the 2nd board | substrate 20 suitably from these according to the objective of the semiconductor device to manufacture. Of course, other materials may be used.

Next, as shown in FIG. 4B, hydrogen ions are implanted from the surface (ion implantation surface) 12 of the first substrate 10 to form an ion implantation layer 11 (step b). .

In the formation of the ion implantation layer 11, not only hydrogen ions, but also rare gas ions or both of hydrogen ions and rare gas ions may be ion implanted. Other ion implantation conditions such as implantation energy, implantation dose, implantation temperature, and the like may be appropriately selected so as to obtain a thin film having a predetermined thickness. As a concrete example, and the substrate temperature at the time of injection to 250 ℃ ~400 ℃, the ion implantation depth to 0.5 ㎛, and and the implantation energy in 20 keV~100 keV, 1 × 10 ¹⁶ ~1 × 10 ¹⁷ to injection dose Although what is referred to as / cm <2> is mentioned, It is not limited to these.

In addition, when ion implantation is performed through the oxide film using a single crystal silicon substrate having an oxide film formed on its surface, an effect of suppressing channeling of the implanted ions can be obtained, and variations in the implantation depth of the ions can be further suppressed. As a result, a thin film having a higher film thickness uniformity can be formed.

Next, as shown in FIG. 4C, a surface activation treatment is performed on the ion-implanted surface 12 of the first substrate 10 and the surface 22 on which the second substrate 20 is bonded. (Step c). In addition, the surface 22 to bond the 2nd board | substrate 20 means the surface to bond with a 1st board | substrate in the bonding process of the following process d.

Of course, the surface activation treatment may be performed only on one of the surfaces 12 into which the ion-implanted surface 12 of the first substrate 10 and the surface 22 to be bonded to the second substrate 20 are applied.

At this time, the surface activation treatment may be a plasma treatment. As described above, when the surface activation treatment is performed by plasma treatment, the surface on which the surface activation treatment of the substrate is performed is activated due to an increase in the OH group. Therefore, in this state, when the surface 12 into which the ion-implanted surface 12 of the 1st board | substrate and the 2nd board | substrate are joined are in close contact, the board | substrate can be bonded more firmly by hydrogen bond etc. In addition, the surface activation treatment may also be performed by ozone treatment or the like, or a plurality of treatments may be combined.

In the case of a plasma treatment, a substrate subjected to RCA cleaning or the like is loaded in a vacuum chamber, and after introducing a plasma gas, the surface is exposed to plasma for about 5 to 30 seconds by exposure to a high frequency plasma of about 100 W. Process. As the plasma gas, for example, when treating a single crystal silicon substrate having an oxide film formed on its surface, hydrogen gas, argon gas, or when treating a plasma of oxygen gas or a single crystal silicon substrate having no oxide film formed on its surface, or These mixed gases or a mixed gas of hydrogen gas and helium gas can be used. Moreover, you may use nitrogen gas of inert gas.

In the case of treatment with ozone, a substrate subjected to cleaning such as RCA cleaning is placed in a chamber into which air is introduced, and after introducing plasma gas such as nitrogen gas and argon gas, high frequency plasma is generated to generate oxygen in the atmosphere. Is converted to ozone to ozone the surface.

Next, as shown in FIG.4 (d), the ion-injected surface 12 of the 1st board | substrate and the surface 22 to bond together of a 2nd board | substrate are brought into close contact, and are bonded (process d).

In this way, if the surface subjected to the surface activation treatment is bonded to the substrate at room temperature under reduced pressure or normal pressure, for example, the substrate can be adhered sufficiently firmly to withstand subsequent mechanical peeling without performing a high temperature treatment. Can be bonded.

And in this invention, the atmosphere at the time of performing this joining process makes humidity 30% or less and / or moisture content 6 g / m <3> or less. In addition, "humidity" here refers to relative humidity, ie, the ratio of the moisture content with respect to the saturated moisture content at the temperature.

In addition, since the humidity is low in this manner, static electricity is easily generated on the surface of the substrate, and foreign matters are easily adsorbed. Therefore, it is preferable to suppress the generation of static electricity by using an ionizer.

In addition, after the step of bonding the first substrate and the second substrate, a heat treatment step of heat-treating the bonded substrate at 100 ° C to 400 ° C can be performed.

Thus, after joining a 1st board | substrate and a 2nd board | substrate, the said board | substrate joined is heat-processed at 100 degreeC-400 degreeC, and the intensity | strength of the bonding of a 1st board | substrate and a 2nd board | substrate can be raised. In particular, when the heat treatment temperature is 100 ° C to 300 ° C, thermal distortion, cracking, peeling, etc. due to the difference in thermal expansion coefficient are less likely to occur even when joining substrates of different materials. Increasing the bonding strength can reduce the occurrence of defects in the peeling process.

Next, as shown in Fig. 4E, the first substrate 10 is separated from the ion implantation layer 11, and a peeling step of thinning the first substrate 10 is performed (step e).

The separation (peeling and thinning) of the first substrate can be performed by applying a mechanical external force, for example. In particular, when the external impact is applied from one end of the first substrate and the cleavage proceeds from the one end to which the external impact is applied to the other end, the cleavage occurs in one direction, so that the control of the cleavage is relatively easy. It is preferable to obtain a thin film having a high film thickness uniformity. In addition, in this case, the one end which gives an external impact and the joining start part at the time of the joining of process d are not particularly related, and these positions can be determined by the convenience of a manufacturing process, etc.

Then, the bonding substrate 30 having the thin film 31 on the second substrate 20 as shown in FIG. 4F by going through the above steps (FIGS. 4A to 4E). ).

In the present invention, as described above, when performing the bonding step of step d, the humidity is set to 30% or less and / or the water content is 6 g / m 3 or less, so that the propagation speed of the close contact is slowed down and the deposit is attached at the joining end. Can be efficiently removed to prevent the sealing of deposits. Therefore, a subsequent peeling process (step e) etc. are performed, and it can manufacture by preventing a void generate | occur | producing in a junction terminal part. In the present invention, the lower the humidity (the less water) is, the higher the effect of suppressing the generation of voids at the junction ends, but at that time, it is more reinforcement of the static electricity countermeasure by the ionizer or the like. desirable.

EXAMPLE

Hereinafter, although an Example and a comparative example of this invention are shown and this invention is demonstrated more concretely, this invention is not limited to these.

(Example 1)

As shown below, the bonded substrate was manufactured according to the manufacturing method of the bonded substrate by the bonding method as shown in FIG.

First, a single crystal silicon substrate having a mirror polished diameter of 150 mm was prepared as the first substrate 10. Then, a 100 nm silicon oxide film layer was formed on the surface of the first substrate by thermal oxidation. In addition, a synthetic quartz substrate having a diameter of 150 mm was prepared as the second substrate 20 (step a).

Next, hydrogen ions were implanted into the first substrate 10 through the formed silicon oxide film layer, and a microbubble layer (ion implantation layer) 11 parallel to the surface was formed at an average traveling depth of the ions (step b). In the ion implantation conditions, the implantation energy is 35 keV, the implantation dose is 9 × 10 ¹⁶ / cm 2, and the implantation depth is 0.3 μm.

Next, after loading the first substrate 10 ion-implanted into the plasma processing apparatus and introducing nitrogen as the plasma gas, a high frequency of 13.56 MHz is 300 mm in diameter under a reduced pressure of 2 Torr (270 kPa). The high frequency plasma treatment was performed for 10 seconds on the ion implanted surface by applying the high frequency power between the parallel plate electrodes under the condition of 50 W. In this manner, the surface activation treatment was performed on the ion implantation surface 12 of the first substrate 10.

On the other hand, the second substrate 20 is loaded in a plasma processing apparatus, nitrogen gas is introduced as a plasma gas between the narrow electrodes, and then plasma is generated by applying a high frequency between the electrodes to perform a high frequency plasma treatment for 10 seconds. It was. In this manner, the surface activation treatment was also performed on the surface 22 of the second substrate 20 to be bonded in the next bonding step (step c).

After making the 1st board | substrate 10 and the 2nd board | substrate 20 which performed the surface activation process as mentioned above adhere | attach at room temperature using the surface which performed the surface activation process as a joining surface, the back surface of both board | substrates is strongly strengthened in the thickness direction. (Press d).

In addition, the atmosphere at the time of this joining was made into the temperature of 20 degreeC, and water content 6g / m <3>. In other words, the relative humidity is 33%.

In addition, the aspect of the propagation of the close contact portion was observed from the second substrate (transparent synthetic quartz substrate) side at this time. In the vicinity of the junction termination part, there existed the aspect of the electric wave as shown to Fig.1 (a).

Next, in order to raise the bonding strength, the board | substrate which bonded the 1st board | substrate 10 and the 2nd board | substrate 20 was heat-processed at 300 degreeC for 6 hours.

Next, in order to form the starting point of the cleavage, an external impact was applied to the ion implantation layer 11 of the first substrate by one end of the scissors for stationery. Thereafter, the first substrate 10 and the second substrate are relatively separated from each other so that the ion implantation layer is directed from the one end to which the external impact is applied to the first substrate 10 and the second substrate 20 toward the other end. In (11) it was separated sequentially (step e).

In this way, the bonded substrate 30 having the thin film 31 on the second substrate 20 was manufactured. As a result of observing the bonded substrate 30 from the second substrate (transparent synthetic quartz substrate), almost no voids were observed in the substrate surface, and about two voids were observed at the bonded end portions.

(Example 2)

In the same manner as in Example 1, however, the bonding substrate was manufactured by setting the atmosphere at the time of bonding in the bonding step (step d) to a temperature of 20 ° C. and a moisture content of 5 g / m 3, that is, a relative humidity of 27%.

Thus, when the generation | occurrence | production situation of the void of the bonded board | substrate manufactured in this way was observed similarly to the case of Example 1, a void was hardly seen in a board | substrate surface, and the void was not seen in a junction terminal part.

(Example 3)

In the same manner as in Example 1, however, the bonding substrate was manufactured by setting the atmosphere at the time of bonding in the bonding step (step d) to a temperature of 25 ° C. and a water content of 6 g / m 3, that is, a relative humidity of 24%.

Thus, when the generation | occurrence | production situation of the void of the bonded board | substrate manufactured in this way was observed similarly to the case of Example 1, a void was hardly seen in a board | substrate surface, and the void was not seen in a junction terminal part.

(Comparative Example)

In the same manner as in Example 1, however, the bonding substrate was manufactured with an atmosphere at the time of bonding in the bonding step (step d) at a temperature of 20 ° C. and a moisture content of 10 g / m 3, that is, a relative humidity of 55%.

The mode of propagation of the tight contact portion was observed in the same manner as in the case of Example 1, and in the vicinity of the junction end, the mode of propagation as shown in Fig. 1B was obtained.

Thus, when the generation | occurrence | production situation of the void of the bonded board | substrate thus manufactured was observed similarly to the case of Example 1, many voids were seen in the junction terminal part.

From the above result, the effect of this invention that the generation | occurrence | production of the void of a joining terminal part can be prevented by making humidity at the time of joining 30% or less and / or moisture content 6g / m <3> or less became clear.

In addition, this invention is not limited to the said embodiment. The said embodiment is an illustration, It has the structure substantially the same as the technical idea described in the claim of this invention, and what exhibits the same effect is included in the technical scope of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the aspect of the propagation of the contact | adherence part in a junction terminal part typically, (a) is a case of the low humidity which concerns on this invention, (b) shows the case of the conventional high humidity.

It is explanatory drawing which shows typically the aspect of the propagation of the contact | adherence part in a junction start part.

3 is a graph showing the relationship between the moisture content and relative humidity in the atmosphere and the bonding speed.

It is a flowchart which shows an example of the manufacturing method of the bonded substrate which can apply the manufacturing method of the bonded substrate of this invention.

<Explanation of symbols for the main parts of the drawings>

10... First substrate

11... Ion implantation layer

12... Ion implantation surface

20... Second substrate

22... Joint surface

30... Junction board

31... pellicle

Claims (6)

A method of bonding a first substrate to a second substrate, thinning the first substrate, and manufacturing a bonded substrate having a thin film on the second substrate, at least, Forming an ion implantation layer by implanting hydrogen ions or rare gas ions or both thereof from the surface of the first substrate as a semiconductor substrate; Performing a surface activation treatment on one or both surfaces of the ion-implanted surface of the first substrate and the surface to be bonded to the second substrate, A bonding step of joining the ion-implanted surface of the first substrate and the surface to be bonded to the second substrate in an atmosphere of one or more of 30% or less of humidity and 6 g / m 3 or less of moisture; A peeling process of thinning the first substrate by separating the first substrate from the ion implantation layer. The manufacturing method of the bonded substrate which manufactures the bonded substrate which has a thin film on the said 2nd board | substrate. The method of manufacturing a bonded substrate according to claim 1, wherein the first substrate is any one of a single crystal silicon substrate, a single crystal silicon substrate having an oxide film formed on its surface, and a compound semiconductor substrate. The said 2nd board | substrate is a quartz board | substrate, a sapphire (alumina) board | substrate, a SiC substrate, a borosilicate glass substrate, a crystallized glass substrate, an aluminum nitride substrate, a single crystal silicon substrate, and the oxide film formed in the surface of Claim 1 or 2. A method for producing a bonded substrate, comprising one of a single crystal silicon substrate and a SiGe substrate. The method of manufacturing a bonded substrate according to claim 1 or 2, wherein after the bonding step, a heat treatment step of heat-treating the bonded substrate at 100 ° C to 400 ° C is performed, and then the peeling step is performed. The said surface activation process is performed by a plasma process, The manufacturing method of the bonded substrate of Claim 1 or 2 characterized by the above-mentioned. The one end part of Claim 1 or 2 which provided the external impact from the one end part of the said 1st board | substrate to the space | interval in the said ion implantation layer of the said 1st board | substrate in the said peeling process, and gave this external shock. A method for producing a bonded substrate, which is performed by cleavage that proceeds from the end toward the other end.

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