JP4480318B2 - Composite semiconductor device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a composite semiconductor element in which a compound semiconductor element and an integrated circuit (IC) are combined, and a method for manufacturing the same. The present invention relates to a technique for transferring a compound semiconductor thin film such as IC and InSb onto an integrated circuit.
[0002]
[Prior art]
Compound semiconductors such as InSb, InAs, and GaAs having high electron mobility are suitable as materials for high-sensitivity Hall elements and high-speed electronic devices. Further, there is a composite semiconductor element in which these elements and an integrated circuit having a signal processing function are combined. For example, a Hall IC composed of an InSb Hall element and an Si integrated circuit described in JP-A-61-226982 Is well known. These Hall ICs have an advantage that they are more sensitive to magnetic fields than Si monolithic Hall ICs in which the Hall element part and the signal processing part are formed on the same substrate.
[0003]
[Problems to be solved by the invention]
However, the Hall IC described above has a problem that the Hall element and the IC are separately arranged on the lead frame and the electrodes of these elements are connected by wires, so that the size is larger than that of the Si monolithic Hall IC. .
[0004]
In order to realize a small Hall IC, a structure in which Hall elements are arranged on the IC can be considered. For example, Japanese Patent Laid-Open No. 49-91196 proposes a magnetosensitive element in which a magnetosensitive portion of a compound semiconductor is formed on a semiconductor substrate (IC substrate) on which an amplifying transistor is formed via an insulating layer. . As a specific method for forming a compound semiconductor thin film, it is described that it is directly formed on an insulating layer such as SiO ₂ by sputtering, vapor deposition or the like.
[0005]
In the method of forming a compound semiconductor thin film described above, the IC is a substrate, so that the formation temperature is restricted, the circuit is formed, the substrate has large irregularities, and is directly deposited on the insulating layer. For this reason, it has been difficult to form a high-quality compound semiconductor thin film having high electron mobility. Therefore, despite using a compound semiconductor, a high-sensitivity Hall element cannot be produced, and the superiority over the Si monolithic Hall IC has been significantly reduced.
[0006]
The present invention has been made in view of such problems, and an object of the present invention is to provide characteristics of a compound semiconductor in a composite semiconductor element in which a compound semiconductor element and an IC are combined, such as a Hall IC using InSb as a sensor part. It is an object of the present invention to provide a composite semiconductor device and a method for manufacturing the same that can realize downsizing while utilizing the above.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a composite semiconductor device in which a compound semiconductor device and an integrated circuit are electrically connected, wherein the compound semiconductor device is the integrated semiconductor device. A connection electrode of the laminate in which the compound semiconductor terminal and the electrode pad of the integrated circuit are electrically connected after the electrode pad of the integrated circuit is exposed and transferred onto the circuit through an adhesive. And the compound semiconductor element is a Hall element having In _X1 Ga _{1 -X1} As _Y1 Sb _{1 -Y1} (0 ≦ X1 ≦ 1, 0 ≦ Y1 ≦ 1) as an active layer .
[0009]
The invention according to claim 2 is the invention according to claim 1 , wherein the laminate is a laminate made of gold and titanium.
According to a third aspect of the present invention, there is provided a method of manufacturing a composite semiconductor device in which a compound semiconductor device and an integrated circuit are electrically connected, and a compound semiconductor thin film formed on a substrate is bonded onto the integrated circuit. A step of removing the substrate from the compound semiconductor thin film after transfer adhesion through an agent, a step of etching the compound semiconductor into a predetermined shape by a photolithography method, and a step of exposing only the electrode pads of the integrated circuit If, possess and forming a connection electrode of the stack for electrically connecting the input and terminals of the predetermined shape of the compound semiconductor with the electrode pad, wherein the compound semiconductor thin film is vapor deposited on the mica substrate In _X1 Ga _1-X1 As _Y1 Sb _1-Y1 (0 ≦ X1 ≦ 1, 0 ≦ Y1 ≦ 1) .
[0012]
As described above, the present inventors have conducted extensive studies to solve the above problems, and as a result, transferred and bonded the compound semiconductor thin film formed on a suitable substrate under suitable conditions onto an IC via an adhesive. Then, after forming the compound semiconductor element, it is possible to produce a composite semiconductor element in which the compound semiconductor element is arranged on the IC by electrically connecting with the IC. It has been found that the present invention is effective for realizing a composite semiconductor device that achieves high sensitivity and is also miniaturized, and has led to the present invention.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view of a composite semiconductor device according to the present invention. Indicates a connection electrode connecting the compound semiconductor element and the integrated circuit.
[0014]
2 (a) to 2 (f) are diagrams showing a manufacturing process of the composite semiconductor element of the present invention. First, the adhesive 3 is applied onto the integrated circuit 1 (a), and the compound semiconductor thin film 2a formed on the substrate 5 for thin film formation is attached onto the adhesive 3 (b). Thereafter, the substrate 5 is removed (c) and then patterned to be processed into the shape of the compound semiconductor element 2 (d). Further, the adhesive 3 on the electrode pad 1b is removed (e), then the connection electrode 4 is formed (f), and the compound semiconductor element and the integrated circuit are connected to produce a composite semiconductor element.
[0015]
The formation of the compound semiconductor thin film in the present invention can be carried out under a suitable temperature condition by selecting a thin film forming substrate suitable for the compound semiconductor thin film. Accordingly, the high electron mobility inherent in the compound semiconductor material can be realized, and the compound semiconductor thin film is directly formed on the integrated circuit substrate described in Japanese Patent Laid-Open No. 49-91196 described above. It is a different point.
[0016]
FIG. 3 is a top view of a packaged composite semiconductor device according to the present invention, in which reference numeral 6 denotes an integrated circuit, 7 denotes a compound semiconductor device, 8 denotes a lead frame, 9 denotes a wire, and 10 denotes a molded package. This is significantly reduced in size as compared with a conventional composite semiconductor element in which a compound semiconductor element and an integrated circuit are connected by a wire.
[0017]
That is, according to the present invention, in the composite semiconductor element in which the compound semiconductor element 2 and the integrated circuit 1 are electrically connected, the compound semiconductor element 2 is bonded to the integrated circuit 1 via the adhesive 3. It is characterized by that.
[0018]
According to another aspect of the present invention, the compound semiconductor element is a Hall element having an active layer of In _X1 Ga _{1 -X1} As _Y1 Sb _{1 -Y1} (0 ≦ X1 ≦ 1, 0 ≦ Y1 ≦ 1). It is an element.
[0019]
In the present invention, the function, structure, and material of the compound semiconductor element are not particularly limited, but as the compound semiconductor material in the case of a Hall element, In _X1 Ga _1-X1 As _Y1 Sb _1-Y1 (0 ≦ X1 ≦ 1, 0 ≦ Y1 ≦ 1) is preferable because of high electron mobility. Further, the compound semiconductor element may be in a bulk form or a thin film form and is not particularly limited. For example, when the compound semiconductor is InSb, it may be an InSb bulk or an InSb thin film formed on a GaAs substrate. However, in order to reduce the thickness of the element, after bonding onto an integrated circuit The thin film forming substrate is preferably removed. When mica is used as the thin film forming substrate, it is very preferable because the InSb and InAs thin films having high electron mobility can be obtained and the mica substrate can be easily peeled off after bonding.
[0020]
That is, the present invention relates to a method for manufacturing a composite semiconductor device in which a compound semiconductor device and an integrated circuit are electrically connected, and a compound semiconductor thin film formed on a substrate is bonded to the integrated circuit via an adhesive. Then, a method for producing a composite semiconductor element, comprising: removing the substrate from the compound semiconductor thin film.
[0021]
Further, the present invention is characterized in that the compound semiconductor thin film is In _X1 Ga _{1 -X1} As _Y1 Sb _{1 -Y1} (0 ≦ X1 ≦ 1, 0 ≦ Y1 ≦ 1) formed by vapor deposition on a mica substrate. This is a method for manufacturing a composite semiconductor device.
[0022]
The present invention also includes a step of removing the substrate from the compound semiconductor thin film, then processing the compound semiconductor thin film into a predetermined shape by an etching method, and thereafter removing at least the adhesive on the electrode pad portion of the integrated circuit. A method of manufacturing a composite semiconductor device comprising a step of connecting a compound semiconductor thin film and an electrode pad of an integrated circuit with a conductive thin film.
[0023]
Although it does not specifically limit as adhesive material in this invention, Thermosetting resin, such as an epoxy resin, is preferable from a viewpoint of the ease of a process and heat resistance. The method for applying the adhesive is not particularly limited, but the spin coating method is preferred because it can be applied thinly and uniformly. When applying by this method, it is preferable to select a low-viscosity resin as the adhesive material.
[0024]
In addition, the substrate material of the integrated circuit in the present invention is not particularly limited, but generally Si or GaAs is used and can be selected depending on the application.
[0025]
Specific examples of the present invention will be described below.
The composite semiconductor element shown in FIG. 1 was produced by the process shown in FIG.
First, an epoxy resin as the adhesive 3 was applied on the integrated circuit 1 formed on the Si substrate by spin coating to a thickness of about 2 μm (a). Next, a 1 μm-thick InSb thin film 2a formed by vacuum deposition is applied to the mica substrate 5 on an adhesive, and the epoxy is thermally cured in a thermostat to bond the Si integrated circuit and the InSb thin film (b) Thereafter, the mica substrate was peeled and removed (c).
[0026]
When the electron mobility of the InSb thin film transferred from the mica substrate onto the Si integrated circuit was measured using the van der Pauw method, it was 30000 cm ² / Vs, the same as that on the mica substrate before transfer. The electron mobility was 4000 m ² / Vs when formed directly on the Si integrated circuit via the SiO ₂ layer, which was an extremely high value.
[0027]
Next, a resist pattern having the shape of the Hall element 2 was formed on the InSb thin film by photolithography, and the InSb thin film was etched using an HCl-based etchant to remove the resist (d). Next, a resist pattern was formed in which the Al electrode pad portion of the integrated circuit was an opening, and the epoxy was removed by O ₂ ashing to expose the Al electrode pad (e). Finally, a connection electrode 4 made of a laminate of 1 μm Au and 0.1 μm Ti is formed so as to wire the input / output terminals of the Hall element and a predetermined Al electrode pad of the integrated circuit (f), and the composite semiconductor The device was completed.
[0028]
This composite semiconductor element was die-bonded on a lead frame, then wire bonded, and further transfer molded to produce a mold element.
[0029]
FIG. 3 is a top view of the mold element, and it can be seen that it is extremely small compared to FIG. 4 in the case where the conventional Hall element and the integrated circuit are connected by a wire. In FIG. 4, reference numeral 11 denotes an integrated circuit, 12 denotes a compound semiconductor element, 13 denotes a lead frame, 14 denotes a wire, and 15 denotes a mold package.
[0030]
【The invention's effect】
As described above, according to the present invention, after a compound semiconductor element is formed by transferring and bonding a high-quality compound semiconductor thin film formed on a suitable substrate under suitable conditions onto an integrated circuit via an adhesive. Since the compound semiconductor element and the integrated circuit are electrically connected by the connection electrode, it is possible to provide a composite semiconductor element that combines downsizing while sufficiently achieving the performance achieved by a single compound semiconductor element it can.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a composite semiconductor element in the present invention.
FIG. 2 is a diagram showing an example of a process chart for manufacturing a composite semiconductor element according to the present invention.
FIG. 3 is a top view of a molded composite semiconductor device according to the present invention.
FIG. 4 is a top view of a conventional composite semiconductor device in which a compound semiconductor device and an integrated circuit are connected by a wire.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 6, 11 Integrated circuit 1a The board | substrate 1b in which the circuit was formed Electrode pad 2, 7, 12 Compound semiconductor element 2a Compound semiconductor thin film 3 Adhesive 4 Connection electrode 5 Thin film formation board | substrate 8, 13 Lead frame 9, 14 Wire 10 , 15 Mold package

Claims (3)

In a composite semiconductor element in which a compound semiconductor element and an integrated circuit are electrically connected,
The compound semiconductor element is transferred and bonded to the integrated circuit via an adhesive, and includes a connection electrode of a laminate in which the terminal of the compound semiconductor and the electrode pad of the integrated circuit are electrically connected ,
The compound semiconductor _{device, In X1 Ga 1-X1 As} Y1 Sb 1-Y1 composite semiconductor device characterized by (0 ≦ X1 ≦ 1,0 ≦ Y1 ≦ 1) is a Hall element to the active layer. The composite semiconductor element according to claim 1, wherein the laminate is a laminate made of gold and titanium. In a method for manufacturing a composite semiconductor element in which a compound semiconductor element and an integrated circuit are electrically connected,
After the compound semiconductor thin film formed on the substrate is transferred and adhered to the integrated circuit via an adhesive, the substrate is removed from the compound semiconductor thin film, and the compound semiconductor is formed into a predetermined shape by photolithography. Etching, exposing only the electrode pad of the integrated circuit, forming a connection electrode of a laminate that electrically connects the electrode pad and the input / output terminal of the predetermined shape of the compound semiconductor; I have a,
The compound semiconductor thin film is In _X1 Ga _1-X1 As _Y1 Sb _1-Y1 (0 ≦ X1 ≦ 1, 0 ≦ Y1 ≦ 1) formed by vapor deposition on a mica substrate . Production method.

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