JPH0715867B2 - Thermocompression bonded wafer and method for manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a thermocompression-bonded wafer which is composed of two thermocompression-bonded substrates and has an embedding layer on the surface of one of the substrates to be a mating surface. Regarding

(Prior Art) In recent years, semiconductor wafers required to have high density (high integration), high speed (high response), and high output have been demanded. For that purpose, various epitaxial methods and ion implantation are required. Method, thermocompression bonding method, partial melting recrystallization method (Zone Melting o
n Insulation) and other technologies have been developed.

FIG. 7 is a manufacturing process diagram showing a method for manufacturing a thermocompression-bonded wafer previously envisaged by the present inventor, and specifically, on a surface of one substrate 1 which is a wafer of a pair of substrates to be used. An oxide film 3 is formed in advance, and another substrate 2 (which may be a wafer or a ceramic) is thermocompression bonded to the surface of the oxide film 3 and the back surface of the substrate 1 is polished to form an IC. A thermocompression bonded wafer A having a so-called active region layer 1a which functions as described above is obtained.

In this case, the embedding layer 4 such as a series resistor or a separator to be provided in the thermocompression bonding wafer A was formed in advance on the surface of one substrate 1 and the portion to be the mating surface.

(Problems to be Solved by the Invention) Therefore, in the obtained thermocompression bonded wafer A, the embedding layer 4 is literally embedded in the thermocompression bonded wafer A, and it is possible to determine exactly where the embedding layer 4 is located. I can't figure it out.

Therefore, the present invention has been made to provide a thermocompression bonding wafer capable of confirming the embedded layer from the outside and a method for manufacturing the same.

(Means for Solving the Problems) That is, when the present invention is described with the reference numerals used in the embodiments, the first invention is that a: two substrates 11 and 12 at least one of which is a wafer. In thermocompression bonding, a concave portion 15 is formed on a surface portion which is a mating surface of one substrate 11 which is a wafer, on the scribe line 14 of the one substrate 11 or at a position along the scribe line 14.
To form one or more places.

b: Forming the oxide film 13 on the recess 15 or on the entire surface of the wafer including the recess 15.

c: Fill the recess 15 with a solid 16.

d: A burying layer 18 having a predetermined positional relationship with the recess 15 is formed on a surface portion of the one substrate 11 which is a mating surface, and the burying layer 18 is formed by the scribe line in the a. At any stage between the stage before the formation of 14 and the stage of embedding the solid 16 in c) above.

e: Flattening the wafer surface, and thermocompression bonding the other substrate 12 to the flattened wafer surface.

f: Polishing and removing the one substrate 11 from the back surface side to the oxide film 13 existing at the bottom of the recess 15.

7. A method for manufacturing a thermocompression bonded wafer comprising the above a) to f).

The second invention is a: a surface portion which is a mating surface of one substrate 11 which is a wafer in thermocompression bonding of two substrates 11 and 12 at least one of which is a wafer. The recess 15 is provided on the scribe line 14 of the substrate 11 or at a position along the scribe line 14.
To form one or more places.

b: Forming the oxide film 13 on the recess 15 or on the entire surface of the wafer including the recess 15.

c: Fill the recess 15 with a solid 16.

d: A part of the oxide film 13 is removed, and the recess is
A buried layer 18 'having a predetermined positional relationship with respect to 15 is formed, and this buried layer 18' is formed by the above-mentioned step b.
After the formation of the oxide film 13 in step 1), before the solid 16 is embedded in the above c, or simultaneously with the solid 16 embedded.

e: Flattening the wafer surface, and thermocompression bonding the other substrate 12 to the flattened wafer surface.

f: Polishing and removing the one substrate 11 from the back surface side to the oxide film 13 existing at the bottom of the recess 15.

7. A method for manufacturing a thermocompression bonded wafer comprising the above a) to f).

In the third invention, a: an oxide film 19 is formed on the surface portion of one of the substrates 11 which is a wafer when the two substrates 11 and 12 at least one of which is a wafer are thermocompression bonded. After that, the oxide film 19 is removed at one or a plurality of positions on the scribe line 14 or along the scribe line 14 that have a predetermined positional relationship with the scribe line 14.

b: subjecting the removed portion 17 of the oxide film 19 to selective oxide film 13 indentation processing.

c: Fill the removal section 17 with the solid 16.

d: The scribe line 14 is formed on one of the oxide film 19 and the oxide film 13, which is the surface to be the mating surface of the one substrate 11.
Alternatively, a buried layer 18 having a predetermined positional relationship with the removed portion 17 is formed, and the buried layer 18 is formed from a stage before the formation of the scribe line 14 in the above a to a process in the above c. Do at any stage between the stages of solid 16 embedding.

e: Flattening the wafer surface, and thermocompression bonding the other substrate 12 to the flattened wafer surface.

f: Polishing and removing the one substrate 11 from the back surface side to the oxide film 13.

7. A method for manufacturing a thermocompression bonded wafer comprising the above a) to f).

The fourth invention is: a: a surface portion which is a mating surface of one substrate 11 which is a wafer when thermocompressing two substrates 11 and 12 at least one of which is a wafer. Forming one or a plurality of recesses 15 on the scribe line 14 of the substrate 11 or along the scribe line 14 so as to have a predetermined positional relationship with a specific location of the scribe line 14.

b: Forming the oxide film 13 on the recess 15 or on the entire surface of the wafer including the recess 15.

c: Form a conductor region 21 on the oxide film 13 with a predetermined positional relationship from the recess 15 with or without making a hole in the oxide film 13. thing.

d: After forming the conductor region 21, the surface layer of the conductor region 21 is covered with an insulating layer 22.

e: After covering the conductor region 21 covered with the insulating layer 22 with the solid 23, the surface of the wafer is flattened, and the other substrate 12 is thermocompression bonded to the flattened wafer surface.

f: Polishing and removing the one substrate 11 from the back surface side to the oxide film 13 existing at the bottom of the recess 15.

7. A method for manufacturing a thermocompression bonded wafer comprising the above a) to f).

The fifth invention is composed of two thermocompression-bonded substrates 11 and 12 and one substrate 1
1 is a thermocompression bonding wafer for forming an embedding layer 18 on the surface portion to be a mating surface, on the scribe line 14 of the thermocompression bonding wafer or at a predetermined position along the scribe line 14, the embedding layer 18 or the conductor region. A thermocompression bonding wafer having an exposed oxide film 13 is used as a standard for checking the existence position.

Here, "at least one is a wafer" means that the other substrate may be a wafer, or may be a ceramic, a wafer including an element, or a ceramic.

The "buried layer" means (a) a low resistance layer or a separation layer due to impurities that form a conductive region of the same kind or different kind formed in a connection or partially in the active region, and (b) unevenness of the oxide film. (C) A hole is made in a part of the oxide film.
For example, polysilicon doped with As, P, B, Sb (doped P
oly-Silicon) filled area, (d) other materials for manufacturing devices.

"On the scribe line or along the scribe line" means the position that can be grasped from the scribe line, the bonding pad, grooves other than the scribe line near the scribe line, protrusions, patterns, and other arbitrary marks. Means that.

The "predetermined positional relationship" means a positional relationship in which the position of the buried layer or the buried polysilicon of the surface oxide film can be confirmed by the presence of the recess.

The depth of the “recess 15” is a factor that determines the thickness of the active region layer, and the thickness of the active region layer is controlled by controlling the depth of the recess.

The shape of the "recess 15" is also related to the oxide film portion described later,
Regardless of whether it is linear or dot-shaped, the number thereof is determined by the shape and condition of the buried layer.

“Solid 16” to be filled in the concave portion or the removed portion includes polysilicon, metal, glass, Sio ₂ —Si ₃ N ₄ and SiO ₂
-Si ₃ N ₄ -SiO _2, etc. is used, the solid is formed serves as a reinforcing member.

The "conductor region 21" is a region required in the subsequent device manufacturing, for example, a region having a capacity for memory, or a conductor for connection,
Polysilicon or an appropriate metal is used for this.

As a means for "polishing and removing" one of the substrates that is a wafer, surface grinder (SG), lapping,
Methods such as mechanical chemical (MC) are used.

It should be noted that the exposed shape of the oxide film portion may be linear or dot-like, and the number thereof is sufficient as long as it is necessary for grasping the position of the buried layer.

(Function) In the present invention, an oxide film having a polishing rate (etching rate) significantly different from that of Si is provided as a stopper on the polishing limit surface (eg, SiO ₂ by 6 mol KOH at 50 ° C.).
The etching rate of Si is 0.5 [angstrom / min], and the etching rate of Si is 170
[Angstrom / min]).

As a result, even if the polishing surface is tilted to one side, the etching rate is slowed in the exposed portion of the oxide film, and the etching amount with the other portion is balanced. Therefore, by setting the depth of existence of the oxide film to 0.1 μ or 0.5 μ, the thermocompression bonded wafer having the active region layer of each thickness can be obtained.

In particular, according to the selective oxide film pushing process, the depth of the oxide film can be set arbitrarily, so that the active region layer can be formed extremely thin and uniform.

Then, the thermocompression bonded wafer obtained as described above,
Since the concave portion is located at the scribe line or at a position along the scribe line, the yield in semiconductor chip manufacturing is not reduced, and the standardization of the design can be facilitated.

Further, the thermocompression bonded wafer according to the present invention has an oxide film portion exposed on the surface. The buried layer position can be accurately grasped in the device manufacturing process with reference to the edge of the oxide film portion. As a result, it becomes possible to form a capacitor, a resistor, a transistor, etc. on the active region based on the buried layer which is accurately grasped.

(Example) Hereinafter, the present invention will be described with reference to the accompanying drawings.

1 and 2 are manufacturing process diagrams showing an embodiment of the first invention of the present application. FIG. 1 relates to manufacturing of an SOS (Silicon on Silicon) thermocompression bonding wafer, and FIG. 2 shows an SOI (Silicon on In).
FIG. 3 is a manufacturing process diagram showing another embodiment of the invention of the present application, and FIG.
(A) to (D) are plan views showing an arrangement example of the recessed portion or the removed portion. In the illustrated drawings, both the pair of substrates are wafers.

As shown in the figure, the thermocompression bonding wafer of the present invention is formed by thermocompression bonding two substrates 11 and 12, and an exposed oxide film 13 is provided at a predetermined position corresponding to the scribe line 14 of the thermocompression bonding wafer. Have. This oxide film 13 is used as a standard for confirming the existing position of the buried layer 18 formed in advance. Next, the thermocompression bonding wafer of the present invention will be described in detail according to the manufacturing process.

First, in the manufacturing process example of FIG. 1, a concave portion 15 is formed in advance on the scribe line 14 on the surface (the surface on the side to be the pressure-bonding surface) of the one substrate 11 having the embedded layer 18. The number of the recesses 15 is
In the later-described polishing, the number is sufficient as long as one plane can be determined by this polishing, and even if the number is large, there is no problem.
The shape of the recess 15 may be linear as shown in FIG. 4 (a), or may be dot-shaped as shown in FIG. 4 (b) to (d). When it is dot-like, its shape may be arbitrary. The concave portion 15 has a constant depth (corresponding to a desired active layer thickness) by selective etching by a liquid phase or a vapor phase (including etching using ions or plasma) method using a photoresist technique. Depth).

Then, an oxide film 13 is formed in the recess 15 by thermal oxidation, a CVD method, a sputter deposition method, or the like. At this time, if the oxide film 13 is formed only in the concave portion 15, a SOS thermocompression bonding wafer can be obtained as shown in FIG. 1, and if the oxide film 13 is formed not only in the concave portion 15 but also on the entire surface of the substrate 11. , SO as shown in Figure 2
I A thermocompression bonded wafer can be obtained. Thus, the solid 16 is filled in the recess 15 having the oxide film 13 thus formed for the purpose of reinforcement in preparation for polishing described later. As the solid 16, polysilicon, metal, glass, and _{SiO 2 -Si 3 N 4, SiO} 2 -Si 3 N 4 -
SiO ₂ or the like is selected. In addition, as shown in FIG.
After removing a part of the entire surface oxide film of 11, and filling and planarizing the low resistance polysilicon to form a buried layer 18 ′, after that, the other substrate 12 is thermocompression-bonded and further heat-treated to obtain SOI. Good conductive area 18 ″ that covers part of both wafers
You can also make

Next, the surface of the substrate 11 or the surface of the oxide film 13 in FIG. 2 is polished to eliminate the surface irregularities, and another substrate 12 is thermocompression bonded to the polished surface. Specifically, at a temperature of about 1100 ° C., the two substrates 11 and 12 are thermocompression bonded by their own weight or a little weight if the bonding state is maintained for about 2 hours.

After the substrate 11 is pressure-bonded to the substrate 12 as described above, the back surface of the substrate 11 is polished. In this polishing, a mechanical method and a chemical method are used together in consideration of polishing efficiency. Then, the polishing is continued until the lower end portion of the oxide film 13 formed in the substrate 11 is completely exposed.

That is, a chemical method such as KOH or etching polishing using an organic solvent (organic amine) and a SiO ₂ particle coating liquid (colloidal silica) is adopted just before the completion of polishing, but one method in which etching polishing is in progress is used. If the oxide film 13 is exposed at a portion, the etching rate of SiO ₂ is extremely slow after that, and the etching at that portion does not proceed, and the etching of other portions is continued while performing the correction polishing, and eventually all the portions are exposed. At, the oxide film 13 appears and the etching is substantially stopped. In this way, the polishing limit is determined by the oxide film 13 formed in the substrate 11, and an active region layer corresponding to the constant formation amount of the oxide film 13 (in other words, the depth of the recess 15) is obtained. Become. The edge 13a of the oxide film 13 has a buried layer 18
It is used as a guide for confirming the existence position of. That is, the substrate 11 is polished and removed from the back surface side up to the oxide film 13 existing at the bottom of the recess, and the exposed oxide film 13 is used as an index for confirming the existing position of the embedded layer 18. The embedding layer 18 may be formed at any stage between the stage before the formation of the scribe line 14 and the stage for embedding the solid 16.

The oxide film 13 can also be formed by a selective oxide film pushing method. In this selective oxide film indentation method, the indentation depth is determined by time, and further, the indentation depth can be easily controlled by the control of 0.1 μ unit.

Specifically, as shown in FIG. 3, an oxide film 19 is formed on the surface of the substrate 11, and the oxide film 19 is partially removed on or along the scribe line, and the removed portion is removed.
The oxide film 13 is pushed in by combining the thermal oxidation method, the anodic oxidation method, the O ₂ ion implantation method, and the heat treatment with 17 and then the solid 16 is buried in the step portion formed in the removed portion 17. later,
This is similar to the case of FIGS. 1 and 2. The edge 13a of the oxide film 13 thus obtained is used as a standard for confirming the existing position of the buried layer 18, as described above. That is, the substrate 11 is polished and removed from the back surface side to the oxide film 13 existing at the bottom of the recess, and the exposed oxide film 13 is used as an index for confirming the existing position of the embedded layer 18 as in the previous example. The buried layer 18 may be formed on the surface of the substrate 11 from the beginning, or a hole may be formed in the oxide film 19 after the oxide film 19 is formed, and impurities may be diffused therein by an ion implantation method or the like. Form by pushing.

FIG. 5 is a manufacturing process diagram showing still another embodiment of the present invention. In this case, when the two substrates 11 and 12 are thermocompression bonded, the mating surface of one substrate 11 which is a wafer and The surface portion of the scribe line 14 on the scribe line 14 of the one substrate 11 or at a position along the scribe line 14.
The concave portion 15 is formed so as to have a predetermined positional relationship with respect to the specific portion. There may be one recess 15 or a plurality of recesses.

Then, the oxide film 13 is formed on the recess 15 or on the entire surface of the wafer including the recess 15.

A conductor region 21 is formed on the oxide film 13 with a predetermined positional relationship from the recess 15. This conductor area 21
For example, polysilicon or an appropriate metal is used. The conductor area 21 is formed in a single layer or a laminated shape depending on the purpose.

After molding the conductor region 21, the surface layer of the conductor region 21 is covered with an insulating layer 22. When polysilicon is used for the conductor region 21, an oxide film is formed by leaving the molded necessary region and oxidizing the surface layer, and this oxide film becomes the insulating layer 22. In this way, the conductor region 21 covered with the insulating layer 22 becomes, for example, a memory capacity or connection conductor or resistor in the subsequent device manufacturing.

After covering the conductor region 21 covered with the insulating layer 22 with the solid 23, the surface of the wafer is flattened, and the other substrate 12 is thermocompression bonded to the flattened wafer surface.

Further, similarly to the above-mentioned embodiment, the one substrate 11 is polished and removed from the back surface side until the oxide film 13 existing at the bottom of the recess 15 is reached. The exposed oxide film portion is formed by two thermocompression bonded substrates.
In 11 and 12, it can be used as an index for confirming the existence position of the conductor region 21.

In this way, the conductor area 21 is provided inside the thermocompression bonded wafer, but the thermocompression bonded wafer having such a structure is, as described above, even if the conductor area 21 is present inside. This is an epoch-making one that the existence position can be confirmed from the outside by using the oxide film portion as an index. Therefore, the process of forming the conductor area 21 will now be described in some detail.

In FIG. 6, an oxide film 24 (for example, SiO ₂ or the like), a nitride film (for example, Si ₃ N ₄ or the like), or the like is formed on the surface portion that becomes the mating surface of the substrate 11 (FIG. 6 (1)), and this oxidation is performed. A hole 25 is formed in a predetermined portion of the film 24 (this portion has a predetermined positional relationship with the recess 15 or the scribe line 14 described later) by a photoetching method.
Is formed (FIG. 6 (2)), polysilicon 26 is covered thereon (FIG. 6 (3)), and a photoresist 27 is formed above the hole 25 (FIG. 6 (4)). The polysilicon 26 is cut out by photoetching (FIG. 6 (5)), and the photoresist 27 is removed (FIG. 6 (6)).

Further, a photoresist 28 is formed again on the surface, and the photoresist 28 at a predetermined position on the scribe line 14 is removed by photoetching (FIG. 6 (7)). After that, by etching, a recess 15 is formed at a portion where the photoresist 28 is not present, penetrating the oxide film (FIG. 6 (8)). By removing the photoresist 28 (Fig. 6 (9)) and oxidizing the surface, oxide films 13 and 22 are formed on the surface of the recess 15 and the polysilicon 26 (Fig. 6 (10)). . The polysilicon 26 covered with the oxide films 22 and 24 corresponds to the conductor region 21 in FIG.

Then, a solid 23 is covered on the oxide film 24 to flatten the surface of the wafer (FIG. 6 (11)), and the other substrate 12 is thermocompression bonded to the flattened wafer surface (see FIG. 12)),
Similar to the above embodiment, the one substrate 11 is removed by polishing from the back surface side until the oxide film 13 existing at the bottom of the recess 15 is reached (FIG. 6 (13)). The exposed oxide film portion is formed on the two polysilicon-based substrates 11 and 12 which are thermocompression-bonded.
It serves as an index for confirming the location of the (conductor area 21).

In the embodiments of FIGS. 5 and 6, the conductor region 21 of FIG. 5 becomes a so-called floating island, and the polysilicon 26 (conductor region 21) of FIG. 6 has a contact (with an active region). A conducting part) will be provided.
With respect to this point, it is also possible to form a diffusion conduction region from the surface or form a trench (groove) by electron beam, laser light or the like from the surface when forming an element, and oxidize or fill polysilicon to form a contact. In this way, by forming the polysilicon 26 (conductor region 21) on the bottom portion on the side opposite to the element formation surface, it becomes easier to create capacity,
It can easily cope with high density.

Although only one region is illustrated and described in the embodiments, it is needless to say that the number of these regions is appropriately provided as necessary, and as described above, they may be formed in a single layer or in a laminated shape depending on the purpose. It is needless to say that the techniques used in the above-described embodiments are those of the preceding examples (the techniques described in FIGS. 1 to 3) as appropriate.

The thermocompression bonded wafer thus obtained is subjected to an element manufacturing process on the surface and then cut on the scribe line 14 to be used as a semiconductor element.

(Effects of the Invention) As described above, according to the present invention, the processing (thickness) accuracy is improved, and even if the buried layer or the conductor region is not visible from the outside, the back surface of the thermocompression bonded wafer is oxidized. Since the film portion is exposed, this serves as a guide for confirming the position of the buried layer and the conductor region, and the work in the subsequent device process can be performed easily and rationally.

[Brief description of drawings]

1 and 2 are manufacturing process diagrams showing an embodiment of the first invention of the present application. FIG. 1 relates to manufacturing of an SOS (Silicon on Silicon) thermocompression bonding wafer, and FIG. 2 shows an SOI (Silicon on In).
FIG. 3 is a manufacturing process diagram showing another embodiment of the invention of the present application, and FIGS. 4 (a) to 4 (d) are plan views showing arrangement examples of concave portions or removed portions. FIGS. 5, 5 and 6 are manufacturing process diagrams showing still another embodiment of the present invention, and FIG. 7 is a manufacturing process diagram showing a conventional method for manufacturing a thermocompression bonding wafer. 11,12 …… Substrate, 13 …… Oxide film 14 …… Scribe line, 15 …… Concave 16,23 …… Solid, 18,18 ′ …… Embedded layer 21 …… Conductor area, 22 …… Insulation layer

Claims (5)

[Claims] 1. A method for manufacturing a thermocompression bonded wafer, comprising the following a, b, c, d, e, and f. a: When thermocompression bonding two substrates 11, 12 at least one of which is a wafer, a scribe line 14 of one of the substrates 11 which is a mating surface of the one substrate 11 At the top or along the scribe line 14, the recess 15
To form one or more places. b: Forming the oxide film 13 on the recess 15 or on the entire surface of the wafer including the recess 15. c: Fill the recess 15 with a solid 16. d: A buried layer 18 having a predetermined positional relationship with the recess 15 is formed on a surface portion of the one substrate 11 which is a mating surface, and the buried layer 18 is formed by the scribe line in the a. At any stage between the stage before the formation of 14 and the stage of embedding the solid 16 in c) above. e: Flattening the wafer surface, and thermocompression bonding the other substrate 12 to the flattened wafer surface. f: Polishing and removing the one substrate 11 from the back surface side to the oxide film 13 existing at the bottom of the recess 15. 2. A method for producing a thermocompression bonded wafer, comprising the following a, b, c, d, e, and f. a: When thermocompression bonding two substrates 11, 12 at least one of which is a wafer, a scribe line 14 of one of the substrates 11 which is a mating surface of the one substrate 11 At the top or along the scribe line 14, the recess 15
To form one or more places. b: Forming the oxide film 13 on the recess 15 or on the entire surface of the wafer including the recess 15. c: Fill the recess 15 with a solid 16. d: A part of the oxide film 13 is removed, and the recess is
A buried layer 18 'having a predetermined positional relationship with respect to 15 is formed, and this buried layer 18' is formed by the above-mentioned step b.
After the formation of the oxide film 13 in step 1), before the solid 16 is embedded in the above c, or simultaneously with the solid 16 embedded. e: Flattening the wafer surface, and thermocompression bonding the other substrate 12 to the flattened wafer surface. f: Polishing and removing the one substrate 11 from the back surface side to the oxide film 13 existing at the bottom of the recess 15. 3. A method for producing a thermocompression bonded wafer, comprising the following a, b, c, d, e, and f. a: In thermocompression bonding of two substrates 11 and 12 at least one of which is a wafer, an oxide film 19 is formed on the surface of the one substrate 11 which is a wafer to be a mating surface, and then on the scribe line 14. Alternatively, at a position along the scribe line 14, the oxide film 19 is removed at one or a plurality of locations that have a predetermined positional relationship with the scribe line 14. b: subjecting the removed portion 17 of the oxide film 19 to selective oxide film 13 indentation processing. c: Fill the removal section 17 with the solid 16. d: The scribe line 14 is formed on one of the oxide film 19 and the oxide film 13, which is the surface to be the mating surface of the one substrate 11.
Alternatively, a buried layer 18 having a predetermined positional relationship with the removed portion 17 is formed, and the buried layer 18 is formed from a stage before the formation of the scribe line 14 in the above a to a process in the above c. Do at any stage between the stages of solid 16 embedding. e: Flattening the wafer surface, and thermocompression bonding the other substrate 12 to the flattened wafer surface. f: Polishing and removing the one substrate 11 from the back surface side to the oxide film 13. 4. A method for manufacturing a thermocompression bonded wafer, comprising the following a, b, c, d, e, and f. a: When thermocompression bonding two substrates 11, 12 at least one of which is a wafer, a scribe line 14 of one of the substrates 11 which is a mating surface of the one substrate 11 To form one or a plurality of recesses 15 at a position above or along the scribe line 14 and having a predetermined positional relationship with a specific position of the scribe line 14. b: Forming the oxide film 13 on the recess 15 or on the entire surface of the wafer including the recess 15. c: Form a conductor region 21 on the oxide film 13 with a predetermined positional relationship from the recess 15 with or without making a hole in the oxide film 13. thing. d: After forming the conductor region 21, the surface layer of the conductor region 21 is covered with an insulating layer 22. e: After covering the conductor region 21 covered with the insulating layer 22 with the solid 23, the surface of the wafer is flattened, and the other substrate 12 is thermocompression bonded to the flattened wafer surface. f: Polishing and removing the one substrate 11 from the back surface side to the oxide film 13 existing at the bottom of the recess 15. 5. A thermocompression bonded wafer comprising two thermocompression bonded substrates 11, 12 and a buried layer 18 formed on a surface portion of one substrate 11 which is a mating surface. A scribe line 14 of the thermocompression bonded wafer. At a predetermined position on the top or along the scribe line 14, the buried layer 18 or the conductor region 21
A thermocompression-bonded wafer having an exposed oxide film 13 as a standard for checking the existence position of.