JPH049383B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device. More specifically, a plurality of active layers are stacked in which functional elements such as transistors and conductive wires (hereinafter referred to as wiring) that connect them are integrated, and the functional elements and circuits integrated in different active layers are stacked. The present invention relates to a method of manufacturing semiconductor devices that are organically connected to each other.

FIG. 1 shows an example of the structure of a multilayer semiconductor device. In the figure, 10 is a supporting substrate such as a semiconductor or an insulator, 11 is a first active layer formed on the supporting substrate 10, and 21, 31, 41, 51, 6
1 and 71 are the second layer, third layer, fourth layer,...
...the (n-2)th layer, the (n-1)th layer, the nth active layer, 12 the substrate of the package on which the multilayer semiconductor device 1 is mounted, 13 the bonding pad, 1
4 is a bonding wire. Next, the manufacturing sequence of a conventionally well-known multilayer semiconductor device will be briefly explained using the same figure.

First, a first active layer 11 consisting of functional elements such as transistors and wiring is formed on the surface of a supporting substrate 10 made of semiconductor or the like using a well-known integrated circuit forming process. At this time, a process for bonding with the second layer active layer 21 to be created next is also performed. Next, an insulating film, a semiconductor film, etc. are sequentially formed on the first active layer 11. The most typical example of the semiconductor film is a silicon single crystal film obtained by recrystallizing a polysilicon film by laser annealing or electron beam annealing. Next, after integrating functional elements such as transistors using the semiconductor film, these are connected to form the second active layer 21.
shall be. In this case, as necessary, the functional elements and circuits formed in the first active layer 11 and the second active layer 21 are coupled to each other, and the functional elements and circuits formed in the third active layer 31 to be formed next are Processes for bonding with circuit elements are also performed. Hereinafter, using a process similar to the process for creating the second active layer 21, the active layers of the third layer, fourth layer, ... (n-2) layer, (n-1) layer, n-th layer Layers 31, 41,...5
1, 61, and 71 are sequentially created to form a multilayer semiconductor device 1.

Semiconductor devices manufactured in this way have not only a two-dimensional expansion but also a three-dimensional expansion in the vertical direction, so compared to well-known integrated circuits that only have a two-dimensional expansion, the semiconductor devices have higher integration density, functionality, signal processing ability, etc. is excellent. However, since all the processes for creating each active layer are performed layer by layer and then stacked up, as the number of active layers increases, the time required to create the device (TAT) increases. This results in extremely serious problems such as increased yield and decreased yield. The present invention provides a method for manufacturing a semiconductor device that solves these drawbacks. According to the present invention, a plurality of active layers in which circuit elements such as transistors and conductive wires interconnecting these are integrated are laminated, and the circuit elements of each active layer are mechanically coupled to each other between the layers. A method for manufacturing a semiconductor device forming a multi-layered semiconductor device, the method comprising:
Support substrate made of semiconductor or insulator
(n is an integer of 2 or more) and at least one active layer (hereinafter referred to as the first active layer) is prepared on the surface of each support substrate.
2, 2nd layer, . After that, the supporting substrate is removed leaving the active layers of the second layer, third layer, ... nth layer, and then the surface of the first active layer and the back surface of the second active layer, that is, the transparent After aligning both active layers with each other using an alignment pattern with the surfaces opposite to the substrate facing each other, the connection portion provided on the first active layer and the connection portion provided on the second active layer. are brought into close contact with each other and bonded together. Next, after removing the transparent substrate on the second active layer, the second active layer is A method for manufacturing a semiconductor device is obtained, characterized in that the steps described above are repeated on the active layer of the layer.

Further, according to the present invention, a plurality of active layers in which circuit elements such as transistors and conductive wires interconnecting these are integrated are laminated, and the circuit elements of each active layer are organically coupled to each other between the layers. A semiconductor device manufacturing method for forming a multi-layered semiconductor device, in which n supporting substrates (n is an integer of 2 or more) made of semiconductors or insulators are prepared, and at least one layer is formed on the surface of each supporting substrate. active layers (hereinafter referred to as first layer, second layer, ... nth layer active layer), and a transparent substrate is formed on each of the second layer, third layer, ... nth active layer. After adhesion and bonding with an adhesive material, the support substrate is removed leaving the second, third, ... n-th active layer, and then the surface of the first active layer and the second active layer are removed. With the back sides of the layers facing each other,
After aligning the positions of both active layers with each other using an alignment pattern, the connection portions provided on the first active layer and the connection portions provided on the second active layer are brought into close contact with each other, and both are After bonding and then removing the transparent substrate on the active layer of the second layer, the third layer, the fourth layer
Layer...For the n-th active layer, a plurality of n-layer laminates obtained by repeating the above steps applied to the second active layer are created in parallel. , then removing the support substrate of the other laminates leaving one laminate out of the plurality of laminates, and then stacking the plurality of laminates. method is obtained.

The present invention will be explained in detail below using the drawings. FIG. 2 shows an example of a semiconductor device manufactured by the manufacturing method of the present invention. In the same figure, support substrate 1
0, first layer active layer 11, package substrate 1
2. Elements that are the same as in FIG. 1, such as the second active layer 21, are indicated using the same numbers. Note that the first and second active layers 11 and 21 shown in the figure
is a silicon single crystal film obtained by using a semiconductor such as silicon as a support substrate, sequentially depositing an insulating film such as silicon dioxide and a polysilicon film on this, and then recrystallizing the polysilicon by laser annealing or the like. That is, an example created using SOI (Silicon on Insulator) is shown.

Reference numeral 101 is an insulating film made of silicon dioxide or the like deposited on the support substrate 10 by a vapor phase growth (CVD) method or the like. 104, 105, 106 are drain regions of field effect transistors (hereinafter referred to as FETs);
In the source region and the channel region, using the above semiconductor layer such as silicon formed on the insulating film 101,
Formed by a well-known process. 107 is a gate electrode of the FET, and 102 is an insulating film of silicon dioxide or the like deposited by CVD or the like after forming the gate electrode 107. 108 is the drain region 10
4. After opening a hole for wiring in the insulating film 102 on the source region 105, a metal wiring made of aluminum or the like is deposited by sputtering or the like, and then patterned by photolithography. Reference numeral 109 denotes a pattern (alignment pattern) for aligning the active layers 11 and 21 of the first and second layers, and here, as an example, a case is shown in which they are formed simultaneously with the metal wiring 108 from the same material. Reference numeral 103 indicates an insulating film such as silicon dioxide formed by a CVD method, 110 indicates a vertical wiring made of metal such as aluminum, which is inserted into the hole formed by opening the insulating film 103, and 112 indicates an insulating film formed on the vertical interconnection 110. It is a bump made of metal such as gold. 113 is a transparent heat dissipating material such as artificial diamond that has excellent insulation and thermal conductivity. Although the heat dissipation material is not necessarily required, it is an extremely effective means when the amount of heat generated by the active layer is large. Here, the components of the first active layer 11 are summarized as 101, 102, 103, 104, 105,
106, 107, 108, 109, 110, 11
2,113 etc. Similarly, the second active layer 21
Also, insulating films 201, 202, such as silicon dioxide,
203, FET (204, 205, 206, 20
7,), metal wiring 208, vertical wiring 210, 21
1. Consists of metal bumps 212, transparent heat dissipation material 213, etc.

The active layers 11 and 21 configured as described above are aligned by matching the alignment pattern 209 with the alignment pattern 109 through the transparent heat dissipating materials 113, 213 and the transparent insulating films 103, 201, 202, 203. It is done by letting Also, the first layer, the second layer
Interconnection of the functional elements formed in the active layers 11, 12 of the layers is obtained by joining vertical interconnects, e.g. 211, and metal bumps, e.g. 112, by means such as diffusion welding.

3 to 6 show the method for manufacturing a semiconductor device according to the present invention in the order of steps, and the same elements as those shown in FIGS. 1 and 2 are used in FIGS. 1 and 2. The same number is used.

First, an active layer is formed on the surface of the n
The process starts by preparing two supporting substrates. The supporting substrate is then removed to obtain only the active layer. For this purpose, a transparent substrate such as glass or sapphire is adhered to the surface of the active layer (on the side opposite to the supporting substrate) using a transparent material such as wax. This is shown in FIG. By doing so, the transparent substrate 22 protects the active layer 21, so even if the supporting substrate 20 is removed, the active layer can be prevented from being destroyed. In FIG. 3, 20 is a supporting substrate such as a semiconductor, 21 is an active layer to be the second layer consisting of an insulating film, a heat dissipation material, functional elements, wiring, alignment pattern 209, etc.;
2 is a transparent substrate.

The next step is to remove the support substrate 20. For example, if the supporting substrate is silicon, polishing may be performed using an alkaline or ammonia-based solution, etching may be performed using a mixed solution of HNO ₃ , HF and CH ₃ COOH, or these two methods may be used.
It can be removed by combining two methods.
The above steps are also performed on the third to nth active layers at the same time.

The next step is shown in FIG. 15 is a support substrate 10
and a stage on which the first active layer 11 formed thereon is installed, and a heating device 16 such as a heater.
Equipped with: Further, the stage is a support substrate 10
It also has a well-known suction function to fix it in a predetermined position. 17, the transparent substrate 22 has the bonded second active layer 21 facing downward;
It is a movable device for holding, and has a well-known adsorption function, a well-known aligning function, a function of applying pressure to the transparent substrate, etc., for fixing the transparent substrate. Therefore, while moving the movable device 17 back and forth, right and left, the alignment pattern 209 provided in the second active layer 21 is changed to the alignment pattern 109 provided in the first active layer 11. By matching , the first and second active layers can be aligned with each other. After the alignment is completed, as shown in FIG. 5, the movable device 17 is translated downward, and the metal bumps (for example, 112 in FIG. 2) provided on the first active layer 11 are connected to the metal bumps (for example, 112 in FIG. 2) on the second layer. Vertical wirings (for example, 211 in FIG. 2) provided in the active layer 21 are brought into close contact with each other. At this time, the heating device 1
6, the metal bump and the vertical wiring are, for example,
Heat to around 350 degrees C. At the same time, the movable device 17 is controlled in the direction of the arrow 18, e.g.
If a pressure of about 50 kg/mm ² is applied, metal bumps such as gold and vertical wiring such as aluminum can be diffusion welded. Therefore, the functional elements or circuits in the first and second active layers are interconnected. Next, by removing the transparent substrate 22 from the second active layer 21, the lamination of the second active layer is completed.

The next step is to stack the third active layer 31, from which the support substrate has been removed, on the second active layer 21, as shown in FIG. In this case as well, the method of laminating the second active layer described with reference to FIGS. 3 to 5 is carried out in exactly the same manner. Hereinafter, the semiconductor device 1 as shown in FIG. 1 is formed by sequentially stacking the fourth to nth active layers in the same manner as the stacking method of the second and third active layers. .

The method for manufacturing a multilayer semiconductor device, ie, the stacking method, has been described above in detail. According to the present invention, the creation of the first, second, ... nth active layers and the removal of the support substrate from the second to nth active layers are performed in parallel and at the same time. The time required to create a multilayer semiconductor device according to the present invention is extremely shortened compared to the time required to create a multilayer semiconductor device that is well known in the past. Furthermore, active layers made of semiconductors made of different materials such as silicon and gallium arsenide, or active layers formed using different manufacturing processes such as FETs and bipolar transistors can be laminated freely, allowing for multifunctionality and optimization of functions. , the degree of freedom in design also increases. Furthermore, since active layers with no failures can be selected by conducting circuit tests in advance and then stacking them, a semiconductor device with extremely high yield can be realized. Therefore, productivity is greatly improved. Also, since the alignment pattern provided in the transparent insulating film is freely visible after removing the opaque support substrate, alignment between the layers can be easily achieved using conventional methods. Therefore, there are advantages such as not requiring a large-scale device such as a back alignment device.

In addition, in the method of manufacturing a semiconductor device of the present invention, when stacking an active layer or removing a support substrate, the sizes of the active layer, the support substrate, the transparent substrate, etc. are not limited. In addition, the types of materials used in the above explanation (semiconductor materials, insulating materials, metal materials, heat dissipation materials, adhesive materials, etching solutions, etc.), manufacturing conditions (temperature, pressure, film thickness, etc.), or individual manufacturing methods ( etching, polishing, diffusion welding, etc.)
These are just examples, and the present invention is not limited to the above as long as the effects of the present invention can be achieved. In the above explanation, the active layer formed using SOI was explained as an example, but the explanation is not limited to this, and the active layer is formed using a wide range of general materials, for example, when the active layer is formed on the surface of a semiconductor substrate, or when the active layer is formed on the surface of a semiconductor substrate. It is also applicable when it is formed on an epitaxial semiconductor film or on an SOS Si film. Further, the simple circuit configuration used in the above description is also an example, and the present invention is not limited to this.

In addition, in the above embodiment, n sheets were initially prepared in which only one active layer was formed on the support substrate, but it is not necessary to be limited to this. Alternatively, a plurality of active layers may be formed in advance using a method.

Further, in the above embodiments, a case where three or more active layers are laminated is shown, but the present invention can of course be applied to a case where three or more active layers are laminated.

Further, in the embodiment described above, the n-layer laminate obtained by laminating n active layers one by one was used as a completed semiconductor device, but there is no need to be limited by this understanding. That is, in the present invention, (n+1) layers, (n+2) layers, etc. may be further laminated on this n-layer laminate.

Also, a plurality of n-layer laminates are made in parallel, the supporting substrates for one laminate are left behind, and the supporting substrates for other laminates are removed, and finally they are laminated in the same manner as in the previous example. You may. Conversely, when considering an n-layer laminate as a completed semiconductor device, for example, three n/3-layer laminates are manufactured in parallel, and finally these three are laminated to form an n-layer semiconductor device. may be completed.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a structural example of a multilayer semiconductor device, FIG. 2 is a schematic sectional view of a structural example of a multilayer semiconductor device using SOI, and FIGS. 3 to 6 illustrate the manufacturing method of the present invention. For illustrative purposes, they are schematic cross-sectional views showing the structure of a multilayer semiconductor device in the order of its steps.
1 to 6, 1 is a multilayer semiconductor device, 10 and 20 are support substrates, 12 is a package substrate, 13 is a bonding pad, 14 is a bonding wire, 15 is a stage, 16 is a heating device, 17 is a movable device, 18 is a direction of pressurization, 11,
21, 31, 41, 51, 61, and 71 are the first layer, second layer, third layer, fourth layer, and (n-2) layer, respectively.
layer, (n-1)th layer and nth active layer, 22
is a transparent substrate, and 109, 209, and 309 are alignment patterns. In Fig. 2, 101, 102,
103, 201, 202, 203 are insulating films, 10
4,204 is a drain region, 105,205 is a source region, 106,206 is a channel region, 10
7,207 is a gate, 108,208 is a wiring, 1
10, 210, 211 are vertical wiring, 112, 21
2 is a metal bump, and 113, 213 is a heat dissipation material.

Claims (1)

[Claims] 1. A plurality of active layers in which circuit elements such as transistors and conductive wires interconnecting these are integrated, and the circuit elements of each active layer are organically coupled to each other between the layers. A semiconductor device manufacturing method for forming a multi-layered semiconductor device, in which n supporting substrates made of semiconductors or insulators are formed (n is 2).
(an integer greater than or equal to
layer,...referred to as the nth active layer), and the second layer is formed.
After adhering and bonding transparent substrates on the active layers of the second, third, and nth layers using transparent adhesive materials, the active layers of the second, third, and nth layers are left and supported. The substrate is removed, and then the front surface of the first active layer faces the back surface of the second active layer, and after aligning both active layers with each other using an alignment pattern, the first active layer The connecting portion provided in the layer and the connecting portion provided in the active layer of the second layer are brought into close contact with each other,
After bonding the two, and then removing the transparent substrate on the second active layer, the third layer, the fourth layer, ... the n-th active layer, and the second active layer. A method for manufacturing a semiconductor device, characterized in that the steps described above are repeated. 2. A multi-layer semiconductor in which a plurality of active layers are laminated, in which circuit elements such as transistors and conductive wires that interconnect them are integrated, and the circuit elements in each active layer are organically bonded to each other between the layers. A method for manufacturing a semiconductor device forming a device, in which n supporting substrates (n is an integer of 2 or more) made of a semiconductor or an insulator are prepared, and at least one active layer (hereinafter referred to as 1st layer, 2nd layer
layer,...referred to as the nth active layer), and the second layer is formed.
After adhering and bonding transparent substrates on the active layers of the layers, third layer, ... nth layer with transparent adhesive materials, the active layers of the second layer, third layer, ..., nth layer are left. The support substrate is removed, and then the surface of the first active layer and the second layer are removed.
After aligning the back sides of the active layers of the layers with each other using an alignment pattern, the first
After the connection portion provided on the active layer of the layer and the connection portion provided on the active layer of the second layer are brought into close contact with each other and bonded together, and then the transparent substrate on the active layer of the second layer is removed. , the third layer, the fourth layer, ... an n-layer laminate formed by repeating the steps described above for the second active layer on the n-th active layer. Create a plurality of laminates in parallel, then remove the supporting substrate of the other laminates while leaving one laminate among the laminates, and then laminate the multiple laminates. A method for manufacturing a semiconductor device, characterized by: