JP2007152554A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device having a microstructure and a semiconductor element which are provided on a same substrate in a same step. <P>SOLUTION: A first sacrificial layer 103 is provided on an area to be a microstructure on a substrate 101, and a structure layer 105 is provided above the layer. A semiconductor layer 104 is film formed on an area to be a semiconductor element. Polycrystalline silicon which is crystallized by a metal is used for the structure layer. This polycrystalline silicon is different from general polycrystalline silicon, the covalent binding is not broken in a crystalline grain boundary, the fracture strength is high, and it is suitable for the structure layer. Moreover, this polycrystalline silicon can be used as the semiconductor layer 104, and the microstructure and the semiconductor element can be provided on the same substrate. Continuously, a second sacrificial layer 108 is provided on the structure layer, and an electrically conductive layer or the like is provided on the semiconductor layer. Finally, the first and second sacrificial layers are removed and the microstructure having spaces below and above the structure layer is obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a semiconductor device including a microstructure and a semiconductor element over the same substrate and a manufacturing method thereof.

In recent years, research on micro mechanical systems called MEMS has been actively conducted. MEMS (
Micro Electro Mechanical System) is an abbreviation for a microelectromechanical system, and may be simply called a micromachine. A micromachine generally refers to a micro device in which a “micro structure having a three-dimensional structure and a movable structure” and an “electronic circuit having a semiconductor element” are integrated using a semiconductor micro processing technique. Unlike the semiconductor element, the microstructure has a three-dimensional structure and has a movable portion. And it has functions, such as a switch, variable capacity, or an actuator.

Micromachines can control their microstructures with electronic circuits, so they are not a central processing control type as with conventional computer-based devices. It is thought that it is possible to build an autonomous decentralized system that performs a series of actions to take action through the.

Many studies have been made on such micromachines (see Patent Document 1).
Patent Document 1 describes a mechanical device that has been crystallized in a thin film form.
Japanese Patent Application Laid-Open No. 2004-1201

Microstructures and semiconductor elements that make up a micromachine require processes such as sacrificial layer etching when manufacturing microstructures, and are manufactured in separate steps because they have different processes from those used when manufacturing semiconductor elements. It is the mainstream. In addition, how to seal the microstructure is a big problem. Since the processes are different as described above, micromachines that have been put into practical use are mainly those in which a microstructure and a semiconductor element are manufactured in separate steps.

However, there is a demand for a method for manufacturing a microstructure and a semiconductor element in the same process in order to reduce manufacturing costs and downsize an apparatus. Therefore, an object of the present invention is to provide a method for manufacturing a micromachine for forming a microstructure and a semiconductor element over the same insulating substrate. Another object of the present invention is to provide a micromachine manufactured by the above method.

In order to solve the above problems, the present invention includes a layer including polycrystalline silicon that is thermally crystallized or laser-crystallized using a metal (also referred to as a structural layer in this specification), below the layer or A micromachine having a space (also referred to as a hollow) above and a semiconductor device including the micromachine are characterized. Such polycrystalline silicon can be formed on an insulating surface typified by a glass substrate, has high strength, can be used as a microstructure, and can of course constitute a semiconductor element. As a result, a semiconductor device for forming a microstructure and a semiconductor element can be formed over the same insulating substrate.

The space may have a single layer structure or a laminated structure. Such a space is formed by removing the sacrificial layer with an etchant introduced through the contact hole. Therefore, when the semiconductor device is seen in a cross-sectional view, the spaces having a stacked structure are preferably connected by contact holes or the like. In order to reduce the number of steps for removing the sacrificial layer, the spaces are preferably connected by contact holes or the like. In other words, the structure layer (the layer having polycrystalline silicon) can have a structure in which a space is formed above and below, and the layers are stacked through the space. Thus, the spaces provided above and below the structural layer are formed by removing the sacrificial layers provided above and below the structural layer. Therefore, when the semiconductor device is shown in a sectional view in a certain direction, for example, the first space on the substrate, the first structural layer on the first space, and the second space on the first structural layer. In the case where the second structural layer is present on the second space, the first space and the second space are connected by other portions.

Such a space allows the layer having polycrystalline silicon to move. The term “movable” includes, for example, moving up, down, left and right, and rotating around a certain axis. That is, a structural layer (a layer having polycrystalline silicon) sandwiched between upper and lower spaces can move up and down, right and left, or rotate around a certain axis depending on the existence of the space.

Below, the concrete structure of this invention is shown.

One embodiment of the present invention includes an electrical circuit and a microstructure provided over an insulating surface, the electrical circuit includes a semiconductor element, the microstructure includes a layer including polycrystalline silicon, Crystalline silicon is a semiconductor device characterized by thermal crystallization or laser crystallization using a metal.

Another embodiment of the present invention further includes a conductive layer which forms a wiring, and an electrical circuit and a microstructure can be electrically connected by the conductive layer.

Another embodiment of the present invention further includes a counter substrate facing the insulating surface, and among the counter substrates,
An insulating layer which is a protective layer can be provided in a portion facing a region where the microstructure is not provided.

Another embodiment of the present invention further includes a conductive layer that forms wiring and a counter substrate facing the insulating surface, and an electric circuit and a microstructure can be electrically connected by the conductive layer.
An insulating layer which is a protective layer can be provided in a portion of the counter substrate that faces a region where the microstructure is not provided.

Another embodiment of the present invention further includes a first conductive layer that forms the first wiring provided on the insulating surface and a counter substrate facing the insulating surface, and the microstructure includes a microstructure in the counter substrate. An insulating layer, which is a protective layer, can be provided in a portion facing the region that is not provided, and a second conductive layer that forms a second wiring is provided on the protective layer. The electric circuit and the microstructure can be electrically connected by the two conductive layers.

The microstructure and the electric circuit can be protected by the counter substrate. Note that the substrate is not limited to a substrate as long as it has a protecting function, and the microstructure and the electric circuit can be protected by an insulator such as a protective film.

In the present invention, an anisotropic conductive material can be used for connection between wirings (conductive layers), an electric circuit, and a microstructure.

In the present invention, a space is provided between the layer having polycrystalline silicon and the insulating surface.

In the present invention, a first space is provided between the layer having polycrystalline silicon and the insulating surface,
A second space is provided between the layer having polycrystalline silicon and the layer provided on the layer having polycrystalline silicon.

In the present invention, a microstructure includes a conductive layer including a metal element or a metal compound provided over an insulating surface and a layer including polycrystalline silicon provided over the conductive layer. There is a space between the layer including crystalline silicon.

In the present invention, a microstructure includes a conductive layer including a metal element or a metal compound provided over an insulating surface and a layer including polycrystalline silicon provided over the conductive layer. A first space is provided between the layer having crystalline silicon and a second space is provided between the layer having polycrystalline silicon and the layer provided on the layer having polycrystalline silicon.

In the present invention, the microstructure includes a layer including polycrystalline silicon provided over an insulating substrate,
A conductive element including a metal element or a metal compound provided over the layer including polycrystalline silicon, and a space is provided between the layer including polycrystalline silicon and the conductive layer.

In the present invention, the microstructure includes a layer including polycrystalline silicon provided over an insulating substrate,
A conductive layer having a metal element or a metal compound provided over the layer having polycrystalline silicon, and an insulating layer having an organic material or an inorganic material provided on the conductive layer; A first space is provided between the conductive layer and the conductive layer, and a second space is provided between the conductive layer and the insulating layer.

In the present invention, the microstructure includes a layer including polycrystalline silicon provided over an insulating substrate,
A conductive layer having a metal element or a metal compound provided over a layer having polycrystalline silicon, and an insulating layer having an organic material or an inorganic material provided on the conductive layer, and having polycrystalline silicon There is a space between the layer and the conductive layer.

In one embodiment of the manufacturing method of the present invention, a layer including polycrystalline silicon crystallized using a metal is formed over an insulating surface, and a conductive layer including a metal element or a metal compound is formed over the layer including polycrystalline silicon. Forming an insulating layer having silicon oxide or silicon nitride over the conductive layer, forming a sacrificial layer having silicon oxide, silicon nitride, metal element, or metal compound over the insulating layer; A method for manufacturing a semiconductor device is characterized in that a sacrificial layer is removed by etching.

In another embodiment of the present invention, a layer having polycrystalline silicon crystallized using a metal is formed over an insulating surface, and a conductive layer having a metal element or a metal compound is formed over the layer having polycrystalline silicon. A first insulating layer having silicon oxide or silicon nitride is formed on the conductive layer, and a sacrificial layer having silicon oxide, silicon nitride, metal element, or metal compound is formed on the first insulating layer. Forming a second insulating layer having an inorganic material or an organic material on the sacrificial layer, forming a contact hole in the second insulating layer, and introducing an etchant through the contact hole; Is a method for manufacturing a semiconductor device.

In another embodiment of the present invention, a first sacrificial layer including silicon oxide, silicon nitride, a metal element, or a metal compound is formed over a substrate, and a metal is used over the first sacrificial layer. Forming a layer having crystallized polycrystalline silicon, forming a second sacrificial layer having silicon, a compound of silicon, a metal element, or a metal compound on the layer having polycrystalline silicon; A method for manufacturing a semiconductor device is characterized in that a first insulating layer is formed over a layer, and part or all of the first sacrificial layer and the second sacrificial layer are removed by etching.

In another embodiment of the present invention, a first conductive layer including a metal element or a metal compound is formed over a substrate, and silicon oxide, silicon nitride, a metal element, or the first conductive layer is formed over the first conductive layer. A first sacrificial layer having a metal compound is formed, a layer having polycrystalline silicon crystallized using a metal is formed on the sacrificial layer, and a silicon, silicon compound is formed on the layer having polycrystalline silicon. Forming a second sacrificial layer having a metal element or a metal compound, forming a first insulating layer on the second sacrificial layer, and a part of the first sacrificial layer and the second sacrificial layer or A method for manufacturing a semiconductor device is characterized in that the whole is removed by etching.

In another embodiment of the present invention, a layer including polycrystalline silicon crystallized using a metal is formed in first and second regions on an insulating surface, and a metal element or metal is formed on the layer including polycrystalline silicon. Forming a conductive layer having a compound; forming an insulating layer having silicon oxide or silicon nitride on the conductive layer; and sacrificing having silicon oxide, silicon nitride, a metal element, or a metal compound on the insulating layer Forming a layer, removing the sacrificial layer formed in the first region by etching to form a microstructure, and forming a layer including polycrystalline silicon, a conductive layer, and an insulating layer in the second region A semiconductor device manufacturing method is characterized in that a semiconductor element is formed.

In another embodiment of the present invention, a layer including polycrystalline silicon crystallized using a metal is formed in first and second regions on an insulating surface, and a metal element or metal is formed on the layer including polycrystalline silicon. Forming a first conductive layer having a compound, forming an insulating layer having silicon oxide or silicon nitride on the first conductive layer, and forming silicon oxide, silicon nitride, metal element on the insulating layer;
Alternatively, a sacrificial layer having a metal compound is formed, a second conductive layer is formed on the sacrificial layer to form a wiring having a metal element or metal compound, and the sacrificial layer formed in the first region is removed by etching. Then, a microstructure is formed, and a semiconductor element having a layer having polycrystalline silicon, a first conductive layer, and an insulating layer is formed in the second region, and the microstructure and the semiconductor element are formed by wiring. Is a method for manufacturing a semiconductor device.

According to another aspect of the present invention, a layer having polycrystalline silicon crystallized using a metal is formed in first and second regions on a first insulating surface, and a metal element is formed on the layer having polycrystalline silicon. Or a conductive layer having a metal compound is formed, an insulating layer having silicon oxide or silicon nitride is formed over the conductive layer, and a silicon oxide, silicon nitride, metal element, or metal compound is formed over the insulating layer A sacrificial layer is formed, and the sacrificial layer formed in the first region is removed by etching to form a microstructure, and in the second region, a layer including polycrystalline silicon, a conductive layer,
And a semiconductor element having an insulating layer is formed, and a protective layer is formed using silicon oxide, silicon nitride, an organic material, or an inorganic material in a region on the second insulating surface that is not opposed to the microstructure. An insulating layer is formed, and a first insulating surface and a second insulating surface are bonded to each other.

According to another aspect of the present invention, a layer having polycrystalline silicon crystallized using a metal is formed in first and second regions on a first insulating surface, and a metal element is formed on the layer having polycrystalline silicon. Or a conductive layer having a metal compound is formed, an insulating layer having silicon oxide or silicon nitride is formed over the conductive layer, and a silicon oxide, silicon nitride, metal element, or metal compound is formed over the insulating layer A sacrificial layer is formed, a first wiring having a metal element or a metal compound is formed on the sacrificial layer, and the sacrificial layer formed in the first region is removed by etching to form a microstructure. In the second region, a semiconductor element having a polycrystalline silicon layer, a conductive layer, and an insulating layer is formed, and the microstructure and the semiconductor element are electrically connected by wiring, On an insulating surface An insulating layer serving as a protective layer is formed using silicon oxide, silicon nitride, an organic material, or an inorganic material in a region not facing the structure body, and the first insulating surface and the second insulating surface are bonded to each other. This is a method for manufacturing a semiconductor device.

In another embodiment of the present invention, a layer including polycrystalline silicon crystallized using a metal is formed in first and second regions on an insulating surface, and a metal element or metal is formed on the layer including polycrystalline silicon. Forming a conductive layer having a compound; forming an insulating layer having silicon oxide or silicon nitride on the conductive layer; and sacrificing having silicon oxide, silicon nitride, a metal element, or a metal compound on the insulating layer Forming a layer, forming a first wiring having a metal element or a metal compound over the sacrificial layer, removing the sacrificial layer formed in the first region by etching, forming a microstructure, In the second region, a semiconductor element having a layer having polycrystalline silicon, a conductive layer, and an insulating layer is formed, and the microstructure and the semiconductor element are electrically connected by the first wiring, On an insulating surface A protective layer is formed using silicon oxide, silicon nitride, an organic material, or an inorganic material in a region not facing the structure, and a second wiring having a metal element or a metal compound is formed on the protective layer, A method for manufacturing a semiconductor device is characterized in that a first insulating surface and a second insulating surface are bonded so that the first wiring and the second wiring are electrically connected.

In another embodiment of the present invention, the first region on the substrate includes silicon oxide, silicon nitride,
A first sacrificial layer having a metal element or a metal compound was formed, and crystallized using metal on the first sacrificial layer formed in the first region and the second region on the substrate. A layer having polycrystalline silicon is formed, and a layer having silicon, a compound of silicon, a metal element, or a metal compound is formed on the layer having polycrystalline silicon formed in the first region and the second region. Forming a second sacrificial layer and a first conductive layer, forming a first insulating layer on the second sacrificial layer and the first conductive layer, and in the first region, A semiconductor element having a microstructure formed by removing part or all of the sacrificial layer and the second sacrificial layer by etching, and having a layer having polycrystalline silicon and a first conductive layer in the second region Of manufacturing a semiconductor device characterized by manufacturing a semiconductor device It is.

In another embodiment of the present invention, a first conductive layer having a metal element or a metal compound is formed in a first region on a substrate, and the first conductive layer formed in the first region is formed on the first region. , Silicon oxide,
Forming a first sacrificial layer having silicon nitride, a metal element, or a metal compound, using a metal on the first sacrificial layer formed in the first region, and on the second region on the substrate; A layer having crystallized polycrystalline silicon is formed, and silicon, a compound of silicon, a metal element, or a metal compound is formed on the layer having polycrystalline silicon formed in the first region and the second region. Forming a second sacrificial layer and a second conductive layer; forming a first insulating layer on the second sacrificial layer and the second conductive layer; and Removing a part or all of the first sacrificial layer and the second sacrificial layer by etching to form a microstructure in the first region, and a layer having polycrystalline silicon in the second region and Producing a semiconductor element having a second conductive layer; A method for manufacturing a semiconductor device according to symptoms.

In another embodiment of the present invention, a contact hole is provided in the first insulating layer, a third conductive layer having a metal element or a metal compound is formed on the first insulating layer and in the contact hole,
In the first region, part or all of the first sacrificial layer and the second sacrificial layer is removed by etching.

In another embodiment of the present invention, a first sacrificial layer including silicon oxide, silicon nitride, a metal element, or a metal compound is formed over a substrate, and a metal is used over the first sacrificial layer. Forming a layer having crystallized polycrystalline silicon, on the layer having polycrystalline silicon,
Forming a second sacrificial layer having a compound of silicon, a metal element, or a metal compound, forming a first insulating layer on the second sacrificial layer, and forming the first sacrificial layer and the second sacrificial layer A method for manufacturing a semiconductor device is characterized in that a part or the whole is removed by etching, a second insulating layer is formed over a counter substrate, and the substrate and the counter substrate are bonded to face each other.

In another embodiment of the present invention, a first conductive layer including a metal element or a metal compound is formed over a substrate, and silicon oxide, silicon nitride, a metal element, or the first conductive layer is formed over the first conductive layer. A first sacrificial layer having a metal compound is formed, a layer having polycrystalline silicon crystallized using a metal is formed on the sacrificial layer, and a silicon, silicon compound is formed on the layer having polycrystalline silicon. Forming a second sacrificial layer having a metal element or a metal compound, forming a first insulating layer on the second sacrificial layer, and a part of the first sacrificial layer and the second sacrificial layer or A method for manufacturing a semiconductor device is characterized in that the whole is removed by etching, a second insulating layer is formed over a counter substrate, and the substrate and the counter substrate are bonded to face each other.

In another embodiment of the present invention, the first region on the substrate includes silicon oxide, silicon nitride,
A first sacrificial layer having a metal element or a metal compound was formed, and crystallized using metal on the first sacrificial layer formed in the first region and the second region on the substrate. A layer having polycrystalline silicon is formed, and a layer having silicon, a compound of silicon, a metal element, or a metal compound is formed on the layer having polycrystalline silicon formed in the first region and the second region. Forming a second sacrificial layer and a first conductive layer, forming a first insulating layer on the second sacrificial layer and the first conductive layer, and in the first region, By removing a part or all of the sacrificial layer and the second sacrificial layer by etching, a microstructure is formed in the first region, and the layer including polycrystalline silicon and the first region are formed in the second region. A semiconductor element having a conductive layer is fabricated and a second insulating layer is formed on the counter substrate. To form a layer, a method for manufacturing a semiconductor device characterized by bonding to face each other and the substrate and the counter substrate.

In another embodiment of the present invention, a first conductive layer having a metal element or a metal compound is formed in a first region on a substrate, and the first conductive layer formed in the first region is formed on the first region. , Silicon oxide,
Forming a first sacrificial layer having silicon nitride, a metal element, or a metal compound, using a metal on the first sacrificial layer formed in the first region, and on the second region on the substrate; A layer having crystallized polycrystalline silicon is formed, and silicon, a compound of silicon, a metal element, or a metal compound is formed on the layer having polycrystalline silicon formed in the first region and the second region. Forming a second sacrificial layer and a second conductive layer; forming a first insulating layer on the second sacrificial layer and the second conductive layer; and And removing a part or all of the first sacrificial layer and the second sacrificial layer by etching to produce a microstructure in the first region and a layer having polycrystalline silicon in the second region And a semiconductor element having a second conductive layer A second insulating layer formed on the plate, a method for manufacturing a semiconductor device characterized by bonding to face each other and the substrate and the counter substrate.

In another embodiment of the present invention, a contact hole is provided in the first insulating layer, a third conductive layer having a metal element or a metal compound is formed on the first insulating layer and in the contact hole,
In the first region, part or all of the first sacrificial layer and the second sacrificial layer is removed by etching, a second insulating layer is formed on the counter substrate, and the second insulating layer is formed on the second insulating layer. A fourth conductive layer containing a metal element or metal compound is formed, and anisotropic conductivity is performed so that the substrate and the counter substrate face each other, and the third conductive layer and the fourth conductive layer are electrically connected. It is characterized by bonding using a material.

In another embodiment of the present invention, a first contact hole is provided in the first insulating layer, and a third conductive layer having a metal element or a metal compound on the first insulating layer and in the first contact hole is provided. A third insulating layer is formed on the third conductive layer, a second contact hole is provided on the third insulating layer, and a metal is formed on the third insulating layer and the second contact hole. A fifth conductive layer having an element or a metal compound is formed, and in the first region, part or all of the first sacrificial layer and the second sacrificial layer is removed by etching, and the first sacrificial layer is formed on the counter substrate. Forming a second insulating layer, forming a fourth conductive layer having a metal element or a metal compound on the second insulating layer;
The substrate and the counter substrate face each other, and the fifth conductive layer and the fourth conductive layer are bonded together using an anisotropic conductive material so as to be electrically connected.

Another embodiment of the present invention is characterized in that the second insulating layer is formed in a region that is not opposed to a region in which part or all of the first sacrificial layer and the second sacrificial layer are removed by etching. .

  Another embodiment of the present invention is characterized in that a substrate having an insulating surface is used.

Another embodiment of the present invention is characterized in that the layer having polycrystalline silicon uses polycrystalline silicon that is thermally crystallized or laser crystallized using a metal added to a selective region.

Another embodiment of the present invention is characterized in that the layer having polycrystalline silicon is a stacked layer of polycrystalline silicon thermally crystallized or laser-crystallized using a metal and amorphous silicon.

In another embodiment of the present invention, the metal for crystallizing polycrystalline silicon is Ni, Fe,
Any one or more of Ru, Rh, Pd, Pd, Os, Ir, Pt, Cu, or Au is used.

Note that the first to fifth spaces here are called for convenience. Therefore,
For example, a space that is partially connected may be called a first space and a second space.

The present invention provides a microstructure that can withstand external force and stress by using polycrystalline silicon crystallized using a metal such as nickel (Ni) for a structural layer of a microstructure and an active layer of a semiconductor element,
In addition, a semiconductor device in which a semiconductor element having excellent element characteristics is formed over the same substrate can be provided. Furthermore, the present invention provides a microstructure and a semiconductor element on the same substrate,
It is possible to provide a semiconductor device which does not require assembly or a package and does not require manufacturing costs.

Embodiments and examples of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following description. It will be readily understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the following embodiments and examples. Note that in describing the structure of the present invention with reference to the drawings, the same portions are denoted by the same reference numerals in different drawings.

(Embodiment 1)
In this embodiment mode, a structural example of a semiconductor device of the present invention and a manufacturing method thereof will be described with reference to drawings.

The semiconductor device of the present invention belongs to the field of micromachines, and has a size from micrometer to millimeter. Further, when manufactured to be incorporated as a part of a certain mechanical device, the semiconductor device may have a size of a metric unit so that it can be easily handled during assembly.

FIG. 1 shows a conceptual diagram of a semiconductor device of the present invention.

The semiconductor device 11 of the present invention includes an electric circuit portion 12 having a semiconductor element and a structure portion 13 constituted by a microstructure. The electric circuit unit 12 includes a control circuit 14 that controls the microstructure, an interface 15 that communicates with the external control device 10, and the like. The structure body 13 includes a sensor 16, an actuator 17, a switch, and the like that are formed of a microstructure.

The electric circuit unit 12 can also include a central processing unit for processing information obtained by the structure unit 13, a memory for storing the processed information, and the like.

The external control device 10 is a device for performing operations such as transmitting a signal for controlling the semiconductor device 11, receiving information obtained by the semiconductor device 11, and supplying driving power to the semiconductor device 11.

The present invention is not limited to the above configuration example. That is, the present invention provides a semiconductor device,
Since the semiconductor device includes an electric circuit that controls a microstructure and a microstructure controlled by the electric circuit, the other structures are not limited to those in FIGS.

Conventionally, when dealing with minute objects such as millimeters or less, first the structure of the minute object is expanded, and humans and computers obtain the information to determine information processing and operations, and then reduce the operations. It needs a process of communicating to minute objects.

However, the semiconductor device of the present invention shown in FIG. 1 can handle a minute object simply by a human or computer transmitting a high-level conceptual command. That is, when a human or a computer determines a purpose and transmits an instruction, the semiconductor device can move by obtaining information on an object using a sensor or the like to perform information processing.

In the above example, it is assumed that the object is very small. Such an object includes, for example, a minute signal (for example, a minute change in light or pressure) or the like emitted from the object, although the object itself has a size of a meter unit.

Next, a method for manufacturing a microstructure and a semiconductor element over the same substrate in order to manufacture the semiconductor device of the present invention described above will be described with reference to FIGS. Each drawing shows a top view or a cross-sectional view taken along OP or QR of the top view.

The microstructure and the semiconductor element of the present invention can be formed over a substrate having an insulating surface (hereinafter referred to as an insulating substrate). Here, the insulating substrate is a glass substrate, a quartz substrate, a plastic substrate, or the like. Furthermore, it is also possible to use a conductive substrate such as a metal or a substrate in which an insulating layer is formed over a semiconductor substrate such as silicon. By forming the microstructure and the semiconductor element integrally on the plastic substrate, a highly flexible and thin semiconductor device can be formed. In addition, a thin semiconductor device can be formed by thinning the glass substrate by polishing or the like.

First, the base film 102 is formed over the substrate 101 having an insulating surface (see FIGS. 2A1 and 2A2).
)reference). As the base film 102, an insulating layer such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film can be formed with a single layer or a stacked structure. Although a case where a two-layer structure is used as the base film 102 is described here, a structure in which an insulating layer is stacked in a single layer or two or more layers may be used as the base film 102.

As the first layer of the base film 102, a silicon oxynitride film formed by using a plasma CVD method and using SiH ₄ , NH ₃ , N ₂ O, and H ₂ as a reactive gas is 10 to 200 nm (preferably 50 to 100 nm). In this embodiment, a silicon oxynitride film with a thickness of 50 nm is formed. Next, plasma CVD is applied as the second layer of the base film 102 on the first layer.
A silicon oxynitride film formed using SiH ₄ and N ₂ O as a reaction gas,
A layer having a thickness of 200 nm (preferably 100 to 150 nm) can be formed. In this embodiment, a silicon oxynitride film with a thickness of 100 nm is formed.

Next, a first sacrificial layer 103 is formed over the base film 102 and patterned into an arbitrary shape (see FIGS. 2A1 and 2A2). The first sacrificial layer 103 can be formed using an element or a compound such as tungsten or silicon nitride, such as metal or silicon, and using a sputtering method, a CVD method, or the like. For patterning, a resist mask is formed using a photolithography method, and anisotropic dry etching is performed. The sacrificial layer refers to a layer to be removed in a later step, and a space is provided by removing the sacrificial layer. Such a sacrificial layer can be formed from a material having a metal element, a metal compound, silicon, silicon oxide, or silicon nitride. The sacrificial layer may be a conductor or an insulator.

The film thickness of the first sacrificial layer 103 is determined in consideration of various factors such as the material of the first sacrificial layer 103, the structure and operation method of the microstructure, and the etching method for removing the sacrificial layer. The
For example, if the first sacrificial layer 103 is too thin, the etching agent does not diffuse and is not etched. In addition, a phenomenon occurs in which the structural layer buckles after etching. Furthermore, for example, when a conductive layer is provided below the sacrificial layer and the microstructure is operated with an electrostatic force, specifically, when operating with an electrostatic force between the conductive layer and the structural layer, the first sacrificial layer If it is too thick, there is a possibility that it cannot be driven. Therefore, the first sacrificial layer 103 is, for example, 0.5 μm or more and 3 μm.
It has the following thickness and preferably has a thickness of 1 μm to 2.5 μm.

In addition, when a material having a large internal stress is used as a sacrificial layer, a thick sacrificial layer cannot be formed at a time. In this case, the first sacrificial layer can be formed thick by repeating film formation and patterning.

Next, a semiconductor layer 104 that forms a semiconductor element, and a structural layer 105 that forms a microstructure
A semiconductor layer to be formed is formed and patterned into an arbitrary shape (see FIGS. 2B1 and 2B2). The semiconductor layer (the semiconductor layer 104 and the structural layer 105 are collectively referred to as a semiconductor layer) can be formed using a material containing silicon. Examples of the material having silicon include a material made of silicon and a silicon germanium material having germanium in an amount of about 0.01 to 4.5 atomic%.

The material and film thickness of the structural layer 105 take into consideration various factors such as the thickness of the first sacrificial layer 103, the material of the structural layer 105, the structure of the microstructure, or the etching method for removing the sacrificial layer. It is determined. For example, when the structural layer 105 is formed thick, the internal stress is distributed, which causes warping and buckling. On the other hand, a microstructure can be formed using the structural layer 105 formed using a substance having a large internal stress distribution difference. In addition, if the thickness of the structural layer 105 is small, the microstructure may be buckled by the surface tension of the solution used when the sacrificial layer is etched. As described above, the thickness of the structural layer is set so as not to cause buckling or the like. For example, when the structural layer 105 is formed using the semiconductor layer of this embodiment, the film thickness is preferably 0.5 μm or more and 10 μm or less.

As the semiconductor layer, a semiconductor layer having a crystalline state or an amorphous state can be used; however, in this embodiment mode, an amorphous semiconductor layer is formed and crystallized by heat treatment to be a crystalline semiconductor. Form a layer. For the heat treatment, a heating furnace, laser irradiation, irradiation of light emitted from a lamp instead of a laser beam (hereinafter referred to as lamp annealing), or a combination thereof can be used.

In the case of using laser irradiation, a continuous wave laser beam (CW laser beam) or a pulsed laser beam (pulse laser beam) can be used. As a laser beam, Ar laser, Kr laser, excimer laser, YAG laser, Y ₂ O ₃ laser, YVO ₄
A laser beam oscillated from one or more of laser, YLF laser, YAlO ₃ laser, glass laser, ruby laser, alexandrite laser, Ti: sapphire laser, copper vapor laser, or gold vapor laser can be used. By irradiating the fundamental wave of such a laser beam and the second to fourth harmonic laser beams, a crystal with a large grain size can be obtained. For example, a second harmonic (532 nm) or a third harmonic (355 nm) of an Nd: YVO ₄ laser (fundamental wave 1064 nm) can be used. At this time, the energy density of the laser beam is about 0.01 to 100 MW / cm ² (preferably 0.1 to 10).
MW / cm ² ) is required. Then, irradiation is performed at a scanning speed of about 10 to 2000 cm / sec.

The continuous wave fundamental laser beam and the continuous wave harmonic laser beam may be irradiated, or the continuous wave fundamental laser beam and the pulsed harmonic laser beam may be irradiated. You may do it. By irradiating a plurality of laser beams, energy can be supplemented.

Further, a pulsed laser beam that is oscillated at an oscillation frequency capable of irradiating the next pulsed laser beam before the semiconductor layer is melted by the laser beam and solidified can also be used. . By oscillating the laser beam at such a frequency, crystal grains continuously grown in the scanning direction can be obtained. A specific oscillation frequency of the laser beam is 10 MHz or more, and a frequency band that is significantly higher than a frequency band of several tens to several hundreds Hz that is normally used is used.

When a heating furnace is used as another heat treatment, the amorphous semiconductor layer is heated at 400 to 550 ° C. for 2 to 20 hours. At this time, the temperature is set to 400 to 550 so that the temperature gradually increases.
It is good to set in multiple stages in the range of ° C. In the first low-temperature heating process at about 400 ° C., hydrogen and the like of the amorphous semiconductor layer are generated, so that film roughness during crystallization can be reduced. Furthermore, it is preferable to form a metal that promotes crystallization, such as nickel, on the amorphous semiconductor layer because the heating temperature can be reduced. As metals, Fe, Ru, Rh, Pd, Os, Ir,
Metals such as Pt, Cu, and Au can also be used.

Further, in addition to the heat treatment, the crystalline semiconductor layer may be formed by irradiation using the laser as described above.

The crystal structure of the structure layer 105 formed in this way can be almost the same as that of a single crystal. Therefore, the toughness of the structural layer 105 can be increased. That is, the formed semiconductor layer (produced using silicon in this embodiment mode) is crystallized by performing thermal crystallization using a metal or laser crystallization. As a result, it is possible to obtain the structural layer 105 having higher toughness than ordinary polycrystalline silicon used as the material for the structural layer. Note that normal polycrystalline silicon refers to polycrystalline silicon produced only by thermal crystallization without using a metal. The toughness of the structural layer 105 can be increased in this manner because a semiconductor layer in which crystal grain boundaries are continuous can be formed by a crystallization process. The structure layer 105 has a crystal structure in which the covalent bond is not interrupted at the crystal grain boundary, unlike amorphous silicon or polycrystalline silicon obtained by normal thermal crystallization. Therefore, stress concentration caused by a crystal grain boundary does not occur, and as a result, the fracture stress becomes higher than that of general polycrystalline silicon.

Furthermore, crystalline silicon formed using a metal has continuous crystal grain boundaries. Therefore, the mobility of electrons is large, and it is suitable as a material for the structural layer when the structure is controlled by electrostatic force.

Furthermore, when crystalline silicon is formed using a metal that promotes crystallization, the metal can be included in the crystalline silicon. Therefore, the structure layer can have conductivity,
It is suitable as a semiconductor device for controlling a microstructure with electrostatic force.

Further, since the metal that promotes crystallization becomes a contamination source of the semiconductor device, it can be removed or reduced after crystallization. In this case, after crystallization by heat treatment or laser irradiation,
By forming a layer to be a gettering sink over the semiconductor layer and heating, the metal can be moved to the gettering sink and the metal can be removed or reduced. As the gettering sink, a polycrystalline semiconductor layer or a semiconductor layer to which an impurity is added can be used. For example, a polycrystalline semiconductor layer to which an inert element such as argon is added can be formed over the semiconductor layer, and this can be used as a gettering sink. By adding an inert element, the polycrystalline semiconductor layer can be strained, and the metal can be efficiently captured by the strain. In addition, a metal can be captured by forming a semiconductor layer to which an element such as phosphorus is added.

Polycrystalline silicon manufactured through such a process can be used for the structural layer 105 as it is. In the case where the structure layer 105 needs to have conductivity, the structure layer 105 can be given conductivity by adding an impurity element such as phosphorus, arsenic, or boron. A microstructure having conductivity is suitable as a semiconductor device controlled by an electrostatic force.

Such polycrystalline silicon is also suitable for the semiconductor layer 104. As described above, the polycrystalline silicon of the present invention is produced so that crystal grain boundaries are continuous. Therefore, the mobility of electrons can be increased and the performance of the semiconductor element can be improved.

Next, the first insulating layer 106 that covers the top surface of the structural layer 105 is formed over the semiconductor layer 104 and the structural layer 105 (see FIGS. 2B1 and 2B2). The first insulating layer 106 provided over the semiconductor layer 104 functions as a gate insulating layer. The first insulating layer 106 is formed of the base film 1
As in 02, a material containing silicon such as silicon oxide or silicon nitride can be formed by a plasma CVD method, a sputtering method, or the like. In this embodiment, a 115 nm thick silicon oxynitride film (composition ratio: Si = 32%, O = 59%, N = 7%, H = 2%) is formed as the first insulating layer 106 by a plasma CVD method. Form. Of course, the first insulating layer 1
06 is not limited to the silicon oxynitride film, and an insulating layer containing other silicon may be used as a single layer or a stacked structure.

Alternatively, a metal oxide having a high dielectric constant, for example, hafnium (Hf) oxide can be used as the material of the first insulating layer 106. When such a high dielectric constant material is applied to the gate insulating layer, the semiconductor element can be driven with a low voltage, and a semiconductor device with low power consumption can be provided.

The first insulating layer 106 can be formed by high-density plasma treatment. The high density plasma treatment means that the plasma density is 1 × 10 ¹¹ cm ⁻³ or more, preferably 1 × 10 ^11.
cm ⁻³ to 9 × 10 ¹⁵ cm ⁻³ or less, and microwaves (for example, frequency 2.45 GHz)
This is a plasma treatment using a high frequency such as z). When plasma is generated under such conditions, the low electron temperature is changed from 0.2 eV to 2 eV. As described above, high-density plasma characterized by a low electron temperature has low kinetic energy of active species, so that a film with less plasma damage and fewer defects can be formed.

A substrate on which the semiconductor layer 104 and the structural layer 105 are formed is placed in a film formation chamber that can perform such plasma treatment, and a distance between an electrode for plasma generation, that is, a so-called antenna and an object to be formed is 2.
The film forming process is performed at 0 mm to 80 mm, preferably 20 mm to 60 mm. Such a high-density plasma treatment makes it possible to realize a low-temperature process (substrate temperature of 400 ° C. or lower). Therefore, glass or plastic with low heat resistance can be used as the substrate 101.

The film formation atmosphere of such an insulating layer can be a nitrogen atmosphere or an oxygen atmosphere. The nitrogen atmosphere is typically a mixed atmosphere of nitrogen and a rare gas, or a mixed atmosphere of nitrogen, hydrogen, and a rare gas. As the rare gas, at least one of helium, neon, argon, krypton, and xenon can be used. The oxygen atmosphere is typically a mixed atmosphere of oxygen and a rare gas, a mixed atmosphere of oxygen, hydrogen, and a rare gas, or a mixed atmosphere of dinitrogen monoxide and a rare gas. As the rare gas, at least one of helium, neon, argon, krypton, and xenon can be used.

The insulating layer formed as described above is dense with little damage given to other coatings when the first insulating layer 106 is formed. The insulating layer formed by high-density plasma treatment is
The interface state between the insulating layer and the layer in contact with the insulating layer can be improved. For example, when the first insulating layer 106 is formed using high-density plasma treatment, the interface state with the semiconductor layer can be improved. As a result, the electrical characteristics of the semiconductor element can be improved. Further, by forming the insulating layer over the structural layer in this manner, damage to the microstructure can be reduced and the strength of the structural layer 105 can be maintained.

Here, the case where high-density plasma treatment is used to form the first insulating layer 106 has been described.
The semiconductor layer may be subjected to high density plasma treatment. The semiconductor layer surface can be modified by high-density plasma treatment. As a result, the interface state can be improved, and the electrical characteristics of the semiconductor element can be improved.

Furthermore, not only the first insulating layer 106 but also the base film 102 and other insulating layers can be formed using high-density plasma treatment.

Next, a gate electrode 107 constituting a semiconductor element and a first conductive layer serving as a second sacrificial layer 108 constituting a microstructure are formed over the first insulating layer 106 and patterned into an arbitrary shape. (See FIG. 2 (C1) and (C2)). The first conductive layer (the gate electrode 107 and the second sacrificial layer 108 are collectively referred to as the first conductive layer) is made of a conductive metal or compound such as tungsten, and a sputtering method, a CVD method, or the like is used. Can be used to form a film.

The first conductive layer becomes the second sacrificial layer 108. The second sacrificial layer 108 is replaced with the first sacrificial layer 10.
In the case of etching at the same time, it is desirable to form a film using the same material as the first sacrificial layer 103, for example, tungsten. However, the present invention is not limited to these materials, and the first sacrificial layer 103 and the second sacrificial layer 108 may be formed using different materials.

The first conductive layer serves as the gate electrode 107 of the semiconductor element. Note that the gate electrode 107 can also be formed by stacking the first conductive layer using different conductive materials and etching the first conductive layer in a tapered shape. Note that FIG. 2 shows an example in which a gate electrode is manufactured using a single layer structure.

For patterning, a resist mask is formed using a photolithography method, and anisotropic dry etching is performed. As an example of etching, ICP (Inductive Co
It is possible to use an uplink plasma (inductively coupled plasma) etching method.
At this time, the etching conditions (the amount of power applied to the coil-type electrode, the amount of power applied to the electrode on the substrate 101 side, the temperature of the electrode on the substrate 101 side, etc.) are determined. As an etching gas, a chlorine-based gas typified by Cl ₂ , BCl ₃ , SiCl ₄ or CCl ₄ , a fluorine-based gas typified by CF ₄ , SF ₆ or NF _3, or O ₂ is appropriately used. be able to.

Next, an impurity element is added to the semiconductor layer 104 constituting the semiconductor element to form an N-type impurity region 11.
2 and a P-type impurity region 111 are formed (see FIGS. 3A1 and 3A2). Such an impurity region can be selectively formed by forming a resist mask by a photolithography method and adding an impurity element. The impurity element can be added by an ion doping method or an ion implantation method. Typically, phosphorus (P) or arsenic (As) is used as the impurity element imparting N-type, and boron (B) can be used as the impurity element imparting P-type. An impurity element imparting N-type is preferably added to the N-type impurity region 112 and the P-type impurity region 111 in a concentration range of 1 × 10 ²⁰ to 1 × 10 ²¹ / cm ³ .

Next, an insulating layer made of a nitrogen compound such as silicon nitride or an oxide such as silicon oxide is formed by a plasma CVD method or the like, and the insulating layer is anisotropically etched in the vertical direction, whereby the gate electrode 107 and the second Of the sacrificial layer 108 (hereinafter referred to as sidewall 10).
9) (see FIGS. 3A1 and 3A2). The sidewall 109 can prevent a short channel effect that occurs as the gate length is shortened.

Next, an impurity element is added to the semiconductor layer 104 having the N-type impurity region 112 to form a high-concentration N-type impurity region 110 having an impurity concentration higher than that of the N-type impurity region 112 provided below the sidewall 109. .

In the case where the gate electrode 107 is formed by stacking different conductive materials and having a tapered shape, the sidewall 109 is not necessarily formed. This is because when the gate electrode manufactured in a tapered shape is used, the N-type impurity region 112 and the high-concentration N-type impurity region 110 can be formed by adding the impurity element once.

After the impurity region is formed, heat treatment, infrared light irradiation, or laser light irradiation is performed to activate the impurity element. Simultaneously with activation, plasma damage to the first insulating layer 106 and plasma damage to the interface between the first insulating layer 106 and the semiconductor layer 104 can be recovered. In particular, when the impurity element is activated from the front surface or the back surface using an excimer laser in an atmosphere of room temperature to 300 ° C., effective activation can be performed. YA
You may activate by irradiating the 2nd harmonic of G laser. A YAG laser is a preferred laser irradiation means because it requires less maintenance.

Alternatively, a passivation film made of an insulating material such as silicon oxynitride or silicon oxide may be formed so as to cover the conductive layer or the semiconductor layer 104 that serves as the gate electrode 107. Thereafter, hydrogenation can be performed by heat treatment, infrared light irradiation, or laser light irradiation.
For example, using a plasma CVD method, a silicon oxynitride film is formed to a thickness of 100 nm,
Thereafter, the semiconductor layer 104 can be hydrogenated by heating at 300 to 550 ° C. for 1 to 12 hours using a clean oven. For example, a clean oven is used and heated in a nitrogen atmosphere at 410 ° C. for 1 hour. In this step, dangling bonds in the semiconductor layer 104 generated by addition of the impurity element can be terminated by hydrogen contained in the passivation film. At the same time, the activation process of the impurity region can be performed.

Through the above steps, an N-type semiconductor element 113 and a P-type semiconductor element 114 are formed (see FIGS. 3A1 and 3A2).

Subsequently, a second insulating layer 115 is formed so as to cover the whole (see FIGS. 3B1 and 3B2). The second insulating layer 115 can be formed using an insulating inorganic material, an organic material, or the like.

As the inorganic material, silicon oxide or silicon nitride can be used. As the organic material, polyimide, acrylic, polyamide, polyimide amide, resist, benzocyclobutene, siloxane, or polysilazane can be used. Note that the siloxane resin is Si-O-Si.
Corresponds to a resin containing bonds. Siloxane has a skeleton structure formed of a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group,
Aromatic hydrocarbon). A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent. Polysilazane is formed using a polymer material having a bond of silicon (Si) and nitrogen (N) as a starting material.

Next, the second insulating layer 115 and the first insulating layer 106 are sequentially etched to form a first contact hole 116 (see FIGS. 3B1 and 3B2). As the etching process, a dry etching process or a wet etching process can be applied. In this embodiment mode, the first contact hole 116 is formed by dry etching.

Next, the second conductive layer 11 is formed on the second insulating layer 115 and in the first contact hole 116.
7 is formed and patterned into an arbitrary shape, thereby forming a source electrode, a drain electrode, and a wiring constituting an electric circuit (see FIGS. 3B1 and 3B2). Second conductive layer 11
7 is aluminum (Al), titanium (Ti), molybdenum (Mo), tungsten (W
) Or a film made of silicon (Si) element, or an alloy film using these elements.

In the case of a pattern in which the second conductive layer 117 is rectangular and has corners due to layout restrictions, it is preferable to pattern the second conductive layer 117 into a rounded shape. By patterning in a rounded shape, generation of dust can be suppressed and yield can be improved. The same applies to patterning of a conductive layer such as a gate electrode. Further, when patterning the semiconductor layer, it is preferable to round the corners.

Next, the second insulating layer 115 and the first insulating layer 106 are sequentially etched to form a second contact hole 118, thereby exposing the first sacrificial layer 103 and the second sacrificial layer 108. (See FIGS. 4A1 and 4A2.) 4A1 and 4A2 illustrate only a microstructure. As the etching process, a dry etching process or a wet etching process can be applied. In this embodiment mode, the second contact hole 118 is formed by dry etching. The second contact hole 118 is opened to etch away the first sacrificial layer 103 and the second sacrificial layer 108. Therefore, it is necessary to determine the diameter so that the etching agent flows. For example, the diameter of the second contact hole 118 is preferably 2 μm or more.

The second contact hole 118 includes the first sacrificial layer 103 and the second sacrificial layer 108.
May be formed as a contact hole having a diameter that facilitates etching. That is, it is not necessary to form as a small hole as described above, and the second insulating layer 1 on the semiconductor element or the like.
15 and the second contact hole 118 so that the entire sacrificial layer is exposed, leaving a necessary portion.
May be formed. As a result, the time taken to remove the sacrificial layer can be shortened.

Next, the first sacrificial layer 103 and the second sacrificial layer 108 are attached to the second contact hole 11.
8 is removed by etching (see FIGS. 4B and 4C). By this etching process, a first space 124 is created in the portion where the first sacrificial layer is present, and a second space 126 is created in the portion where the second sacrificial layer is present. For the etching, a wet etching method or a dry etching method suitable for the material of the sacrificial layer can be applied.

For example, when the sacrificial layer is tungsten (W), the sacrificial layer can be removed by immersing it in a solution in which 28% ammonia and 31% hydrogen peroxide water are mixed at a ratio of 1: 2 for about 20 minutes. . When the sacrificial layer is silicon dioxide, the sacrificial layer can be removed by using buffered hydrofluoric acid in which ammonium fluoride is mixed in a ratio of 7 to the 49% hydrofluoric acid aqueous solution 1.
When the sacrificial layer is silicon, alkali metal hydroxide such as phosphoric acid, KOH, NaOH, CsOH, NH ₄ OH, hydrazine, EPD (a mixture of ethylenediamine, pyrocatechol, water), TMAH, IPA, NMD3 solution, etc. Can be used.

When drying after wet etching, to prevent buckling of the microstructure due to capillary action,
Rinsing is performed using an organic solvent having low viscosity (for example, cyclohexane), or drying is performed under conditions of low temperature and low pressure, or a combination of both.

Here, the first sacrificial layer 103 and the second sacrificial layer 108 are formed of different materials,
If etching cannot be performed with the same etchant, the sacrificial layer is etched in two steps.
In this case, it is necessary to determine the etching conditions by sufficiently considering the selection ratio with the structural layer 105 in contact with the etching agent, the second insulating layer 115, or the like.

The sacrificial layer can be removed by dry etching using F ₂ or XeF ₂ under high pressure conditions such as atmospheric pressure.

Furthermore, in order to prevent the microstructure from buckling due to the capillary phenomenon that occurs in the space after the sacrificial layer is removed, plasma treatment for imparting water repellency to the surface of the microstructure can be performed. By using such a process to etch away the first sacrificial layer 103 and the second sacrificial layer 108, a space is generated, and the microstructure 119 can be manufactured.

In the case where the microstructure 119 is moved by an electrostatic force, a third conductive layer 120 that can be used as a common electrode, a control electrode, or the like is preferably formed below the base film 102 (see FIG. 4D). . In the case where the base film 102 has a stacked structure, the third conductive layer 120 can be formed between the base films 102. The third conductive layer 120 is formed by a CVD method or the like using a metal such as tungsten or a conductive material as a material. Moreover, you may pattern into arbitrary shapes as needed.

In the above process, the semiconductor layer 104 and the semiconductor layer 105 are formed over the first sacrificial layer 103, but an insulating layer is formed over the first sacrificial layer 103. Thereafter, a semiconductor layer can be formed. By using such a process, the structural layer 105 can be protected by the insulating layer when the first sacrificial layer 103 is removed, and damage to the structural layer 105 can be reduced.

In the method for manufacturing the microstructure 119 described above, it is necessary to select a material for the structural layer 105, a material for the first sacrificial layer 103, a material for the second sacrificial layer 108, and an etchant that removes the sacrificial layer. is there. For example, when a specific etching agent is determined, the first sacrificial layer 103 and the second sacrificial layer 108 may be formed using a material having a higher etching rate than the material of the structural layer 105.

In addition, the semiconductor layer included in the structural layer 105 is formed by stacking two or more layers including a layer including polycrystalline silicon crystallized using the above steps and a layer including amorphous silicon. It can also be formed. By stacking the semiconductor layers in this manner, the structural layer 105 having both flexibility and hardness can be obtained. Further, the balance between flexibility and hardness can be determined by the ratio of the thicknesses of the layers to be stacked.

Further, it is known that a silicon alloy such as nickel silicide is generally high in strength. By leaving the metal used for crystallization of the semiconductor layer entirely or selectively in the semiconductor layer and applying an appropriate heat treatment, a microstructure that is harder and has higher conductivity can be manufactured.

Further, by laminating the layer in which the metal used for crystallization as described above and the layer having polycrystalline silicon are stacked, a flexible structure layer having excellent conductivity can be obtained. In addition, by stacking layers including amorphous silicon and silicide, a hard structure layer having excellent conductivity can be obtained.

When metal is added to the entire surface and laser irradiation or heat treatment is performed, silicon crystal growth proceeds in a direction perpendicular to the substrate, and metal is selectively added to perform laser irradiation or heat treatment, or metal When crystallization is performed without using, crystal growth proceeds in a direction parallel to the substrate. By laminating two or more layers having different crystal directions, a material having further excellent toughness can be obtained. Since films with different crystal growth directions are stacked, even if breakdown occurs in one layer, cracks hardly propagate to layers with different crystal directions. As a result, it is possible to manufacture a structural layer 105 that is hard to break and has high strength.

The layer having amorphous silicon, the layer having polycrystalline silicon, or the layer having nickel silicide can be repeatedly stacked in order to obtain a required thickness. For example, a layer having polycrystalline silicon can be stacked by repeatedly forming a layer having amorphous silicon and heating. Further, in order to relieve the stress in the film, it may be repeated after the film formation, including patterning.

For example, as illustrated in FIG. 5A, a microstructure can be formed by stacking silicon and silicon compounds having various properties. FIG. 5A illustrates the case where a layer 150 including amorphous silicon, a layer 151 including polycrystalline silicon, and a layer 152 including nickel silicide are stacked over the substrate 101. In the present invention, the layers constituting the microstructure can be arbitrarily selected and stacked. In addition, the above steps can be easily stacked. Therefore, the structural layer 105 having desired properties can be easily manufactured.

Furthermore, the crystallization using a metal as in the above-described step can be partially performed by selectively applying a metal. For example, by applying a metal only to a portion of the structural layer 105 that overlaps with the first sacrificial layer 103, it can be partially crystallized.

The crystallization as described above can be partially crystallized by selective laser irradiation. For example, a structure having a beam structure as shown in FIG. 5B can be obtained by irradiating only a portion of the structural layer 105 overlapping the first sacrificial layer 103 with a laser beam or changing laser irradiation conditions. It is also possible to leave amorphous silicon only in the strut portion 155 of the layer (the portion surrounded by the dotted circle in the figure) and to crystallize only the beam portion 154 of the structural layer and the portion where the structural layer is in contact with the substrate It is.

By partially crystallizing as described above, various combinations of materials can be obtained.
For example, only the driven portion of the structural layer can be crystallized to increase toughness.

Note that the combination of the formation of the structural layer and the sacrificial layer and the crystallization can be freely selected from the above examples and combined. Thereby, the structural layer 10 having flexibility and rigidity is provided.
5 can be produced.

When crystallization is performed by laser crystallization or a combination of a metal and a laser as in the above-described process, the crystallization can be performed at a lower temperature than crystallization by heat alone, so that the range of materials that can be used in the process is widened. For example, when the semiconductor layer is crystallized only by heating, 1000 ° C.
It is necessary to perform heating for about 1 hour at a temperature of about a glass substrate that is vulnerable to heat and a melting point of 10
A metal of 00 ° C. or lower cannot be used as the substrate. However, a glass substrate having a strain point of 593 ° C. can be used by the process using the metal.

In addition, compared with a semiconductor layer only by thermal crystallization, the semiconductor layer manufactured by the above process has continuous crystal grain boundaries, so that the covalent bond is not interrupted. Therefore, stress concentration caused by unpaired bonds between grain boundaries does not occur, and as a result, the fracture stress becomes higher than that of general polycrystalline silicon.

Amorphous silicon has low toughness, but hardly undergoes plastic deformation. That is, it can be said that it is a hard but brittle substance like glass. In the present invention, since laser crystallization is performed, amorphous silicon and polycrystalline silicon can be separately formed depending on the portion of the substrate 101. By doing so, a microstructure 119 in which polycrystalline silicon having continuous grain boundaries excellent in toughness and amorphous silicon that hardly causes plastic deformation can be manufactured.

Amorphous silicon generally has internal residual stress after film formation. For this reason, peeling often occurs when a thick film is formed or laminated. However, since the internal stress is relaxed in the polycrystalline silicon produced by the above process and the film can be formed at a lower temperature process, the film formation and the crystallization can be repeated, and a semiconductor layer having an arbitrary thickness can be formed. Obtainable. It is also possible to form a film on the semiconductor layer by patterning using another material and further form a semiconductor layer thereon.

Further, it is known that a silicon alloy such as nickel silicide is generally high in strength. By selectively leaving nickel used for the catalyst in the semiconductor layer and applying an appropriate heat treatment, a microstructure 119 that is harder and has higher conductivity can be manufactured. Therefore, the thickness of the structural layer 105 can be reduced, and the microstructure 119 with high operation speed and excellent reactivity can be provided.

In addition, according to the present invention, a microstructure and a semiconductor element are manufactured over the same substrate, so that a semiconductor device that does not require assembly or a package and does not require manufacturing costs can be provided.

(Embodiment 2)
Next, in order to manufacture the semiconductor device of the present invention described above, a method for manufacturing a microstructure and a semiconductor element over the same substrate is different from that in Embodiment Mode 1 with reference to FIGS.
Will be described. Each drawing shows a top view, or a cross-sectional view in a top view OP or QR.

The microstructure and the semiconductor element of the present invention can be manufactured over an insulating substrate.

First, a base film 202 is formed over a substrate 201 having an insulating surface (see FIGS. 6A1 and 6A2).
)reference). As the base film 202, an insulating layer such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film can be formed with a single layer or a stacked structure. Here, a case where a two-layer structure similar to that in Embodiment 1 is used as the base film 202 is described; however, the base film 202 may have a structure in which an insulating layer is stacked in a single layer or two or more layers.

Next, a semiconductor layer 204 constituting a semiconductor element and a semiconductor layer 203 constituting a microstructure
Is patterned and patterned into an arbitrary shape (see FIGS. 6A1 and 6A2). Semiconductor layer 2
For 03 and 204, the same material and the same crystal structure as in Embodiment Mode 1 can be used. Then, similarly to Embodiment Mode 1, a crystalline semiconductor layer is formed by heat treatment using a metal.

In addition, since the semiconductor layer containing a metal used for crystallization is excellent in conductivity, the metal is left in the semiconductor layer 203 included in the microstructure and is selectively removed only from the semiconductor layer 204 included in the semiconductor element. It is also possible to do. In addition, when the metal contained in the semiconductor layer 203 included in the microstructure is removed, part of the semiconductor layer 203 included in the microstructure can be used without adding an impurity element. In the case where the semiconductor layer 203 needs to have conductivity when the microstructure is driven, an impurity that becomes P-type or N-type can be added.
This impurity addition can be performed simultaneously with the impurity addition step when forming the impurity region of the semiconductor element. The semiconductor layer 203 made conductive by this process is suitable for the structure of a microstructure controlled by electrostatic force.

Next, a first insulating layer 205 is formed over the semiconductor layers 203 and 204 (FIG. 6A1),
See A2)). The first insulating layer 205 can be formed using a material and a method similar to those of Embodiment 1. The first insulating layer 205 formed in the region of the semiconductor element functions as a gate insulating layer.

The first insulating layer 205 can be formed by high-density plasma treatment, and the conditions and the like are the same as those in Embodiment 1.

Further, the case where high-density plasma treatment is used to form the first insulating layer 205 has been described.
The semiconductor layers 203 and 204 may be subjected to high density plasma treatment. The semiconductor layer surface can be modified by high-density plasma treatment. As a result, the interface state can be improved, and the electrical characteristics of the semiconductor element and the microstructure can be improved. Furthermore, not only the first insulating layer 205 but also the base film 202 and other insulating layers can be formed using high-density plasma treatment.

Next, the first sacrificial layer 206 is formed over the semiconductor layer 203 included in the microstructure and patterned into an arbitrary shape (see FIGS. 6B1 and 6B2). The first sacrificial layer 206 can be formed using an element or a compound such as tungsten or silicon nitride, such as metal or silicon, and a sputtering method, a CVD method, or the like. For patterning, a resist mask is formed using a photolithography method, and anisotropic dry etching is performed.

The thickness of the first sacrificial layer 206 is determined in consideration of various factors such as the material of the first sacrificial layer 206, the structure and operation method of the microstructure, and the etching method for removing the sacrificial layer. Is done. For example, if the first sacrificial layer 206 is too thin, the etching agent does not diffuse and is not etched, or the structure layer buckles after etching. For example, when a conductive layer is provided below the sacrificial layer and the microstructure is operated by electrostatic force, if the first sacrificial layer is too thick, the microstructure is caused by electrostatic force between the conductive layer and the structural layer below the sacrificial layer. There is a risk that it cannot be driven. Therefore, the first sacrificial layer 206 has a thickness of 0.5 μm to 3 μm, and preferably 1 μm to 2.5 μm.

Next, on the first sacrificial layer 206 and the first insulating layer 205, a conductive layer which is the microstructure layer 207 and the second sacrificial layer 208 and serves as the gate electrode 209 of the semiconductor element is formed.
Patterning into an arbitrary shape (see FIGS. 6C1 and 6C2). The conductive layer can be sequentially formed using a conductive metal, a compound, or the like such as tungsten, using a sputtering method, a CVD method, or the like. In this embodiment mode, a structure in which conductive layers are stacked is used. The stacked conductive layers may be formed of the same material or different materials.

A first conductive layer 210 which forms the structure layer 207 of the microstructure and the gate electrode 209 of the semiconductor element is formed. The conductive layer is made of an element selected from Ta, W, Ti, Mo, Al, Cu, or an alloy material or compound material containing the element as a main component, and has a thickness of 50 nm to 2 μm.
What is necessary is just to form. A second conductive layer 211 constituting the second sacrificial layer 208 of the microstructure and the gate electrode 209 of the semiconductor element is formed thereon. The conductive layer is Ta, W, T
An element selected from i, Mo, Al, and Cu, or an alloy material or a compound material containing the element as a main component, may be formed to a thickness of about 100 nm to 2 μm. Alternatively, a semiconductor layer typified by a polycrystalline silicon film doped with an impurity element such as phosphorus, or an AgPdCu alloy may be used as the first conductive layer and the second conductive layer.

The conductive layer is not limited to a two-layer structure, and may have a three-layer structure. For example, tungsten, tungsten nitride or the like is used for the first layer, and an alloy of aluminum and silicon (A
l-Si), an alloy of aluminum and titanium (Al-Ti), a titanium nitride film, a titanium film, or the like may be used as the third layer, and a three-layer structure may be sequentially stacked. In this case, the first layer and the second layer can be the microstructure layer, and the third layer can be the second sacrificial layer. The first layer can be a structural layer, and the second and third layers can be second sacrificial layers. Of course, the conductive layer may have a single layer structure.

Thereafter, patterning is performed in the following procedure to form the structural layer 207, the second sacrificial layer 208, and the gate electrode 209. First, a resist mask is formed in a shape to be etched. Next, the second sacrificial layer 208 and the second conductive layer 211 are etched by using an ICP (Inductively Coupled Plasma) etching method. At this time, the cross section may be vertically patterned by anisotropic etching, or may be etched in a tapered shape. Next, etching conditions such as the amount of power applied to the coil-type electrode, the amount of power applied to the substrate-side electrode, and the electrode temperature on the substrate-side are determined, and the structural layer 207 and the first conductive layer 210 are desired. Etch to taper shape. As an etching gas, a chlorine-based gas typified by Cl ₂ , BCl ₃ , SiCl ₄ or CCl ₄ , a fluorine-based gas typified by CF ₄ , SF ₆ or NF _3, or O ₂ is used. Can do.

When the sacrificial layer is etched to form a microstructure, it is preferable that the second sacrificial layer 208 and the first sacrificial layer 206 be etched at the same time because fewer steps are required. Therefore, the second sacrificial layer 208 is desirably formed using the same material as the first sacrificial layer 206. However, the present invention is not limited to these materials, and the first sacrificial layer 206 and the second sacrificial layer 208 may be manufactured using the same material or different materials.

Next, an impurity element is added to the semiconductor layer 204 included in the semiconductor element to form an N-type impurity region and a P-type impurity region. Such an impurity region can be selectively formed by forming a resist mask by a photolithography method and performing a doping treatment in which an impurity element is added. The impurity element can be added by an ion doping method or an ion implantation method. Typically, phosphorus (P) or arsenic (As) is used as the impurity element imparting N-type, and boron (B) can be used as the impurity element imparting P-type. 1 × 10 ²⁰ to 1 × 10 ²¹ / cm for N-type impurity region and P-type impurity region
It is desirable to add an impurity element imparting N-type in a concentration range of ³ . If necessary,
By alternately repeating the etching of the gate electrode 209 and the doping treatment, the impurity concentration of the semiconductor layer can be controlled and a high concentration impurity region or a low concentration impurity region can be formed.

In the case where the gate electrode 209 is formed with a single conductive layer or when the gate electrode 209 is formed with a stacked conductive layer and is not etched into a tapered shape, an insulating layer is formed over the gate electrode 209 and the insulating layer is formed differently. By performing isotropic etching, an insulating layer (side wall) in contact with the side surface of the gate electrode 209 can be formed. The method for manufacturing the sidewall is the same as in Embodiment Mode 1.

After the impurity region is formed, heat treatment, infrared light irradiation, or laser light irradiation may be performed to activate the impurity element. The activation means is the same as in the first embodiment.

In addition, after a passivation film formed of an insulating layer such as a silicon oxynitride film or a silicon oxide film is formed so as to cover the conductive layer or the semiconductor layer, heat treatment, infrared light irradiation, or laser light irradiation is performed, May also be performed. The hydrogenation conditions are the same as in the first embodiment.

Through the above steps, an N-type semiconductor element 212 and a P-type semiconductor element 213 are formed (see FIGS. 7A1 and 7A2). At this time, impurity regions are formed in regions not covered with the first sacrificial layer 206, the structural layer 207, and the second sacrificial layer 208 in the semiconductor layer 203 included in the microstructure.

Subsequently, a second insulating layer 214 is formed so as to cover the whole (see FIGS. 7A1 and 7A2). The second insulating layer 214 can be formed using an insulating inorganic material, organic material, or the like. The second insulating layer 214 can be manufactured in a manner similar to that of the second insulating layer 115 described in Embodiment 1.

Next, the second insulating layer 214 and the first insulating layer 205 are sequentially etched, and the semiconductor layer 20
3 and 204 and a first contact hole 215 for connecting a wiring to the structural layer 207 are formed (see FIGS. 7A1 and 7A2). As the etching process, a dry etching method or a wet etching method can be applied. In this embodiment mode, the first contact hole 215 is formed by dry etching.

Next, the first contact hole 215 is filled, the third conductive layer 216 is formed so as to cover the second insulating layer 214, and patterned into an arbitrary shape, so that the source electrode, the drain electrode, and the electric Wiring and the like constituting the circuit are formed (see FIGS. 7A1 and 7A2). As the third conductive layer 216, a film made of aluminum (Al), titanium (Ti), molybdenum (Mo), tungsten (W), or silicon (Si) or an alloy film using these elements is used. it can.

As described in Embodiment Mode 1, when the third conductive layer 216 has a pattern having corners, it is preferable to pattern the corner portions into rounded shapes.

Next, the second insulating layer 214 is etched to form second contact holes 217 and 218. The second contact hole 217 is formed to expose the first sacrificial layer 206, and the second contact hole 218 is formed to expose the second sacrificial layer 208 (FIGS. 7B1 and 7B2). )reference). As the etching process, a dry etching method or a wet etching method can be applied.

In this embodiment mode, second contact holes 217 and 218 are formed by dry etching. The second contact holes 217 and 218 are opened to etch away the first sacrificial layer 206 and the second sacrificial layer 208. Therefore, it is necessary to determine the diameter so that the etching agent flows. For example, the diameter of the second contact holes 217 and 218 is preferably 2 μm or more.

In addition, the second contact holes 217 and 218 may be formed as contact holes having a diameter such that the first sacrificial layer 206 and the second sacrificial layer 208 can be easily etched. That is, it is not necessary to form as a small hole as described above, and the semiconductor layers 203 and 204 are not formed.
The second contact holes 217 and 218 may be formed so that the entire sacrificial layer is exposed, leaving a portion where the upper second insulating layer 214 is necessary. As a result, the time taken to remove the sacrificial layer can be shortened.

Next, the first sacrificial layer 206 and the second sacrificial layer 208 are removed by etching (see FIGS. 8A, 8B, and 8C). Here, only the microstructure is displayed in FIG. For the etching, a wet etching method suitable for the material of the sacrificial layer can be used, or a dry etching method can be used, and the sacrificial layer can be removed by etching through the second contact holes 217 and 218.

For example, when the first sacrificial layer or the second sacrificial layer is tungsten (W), it is performed by immersing in a solution in which 28% ammonia and 31% hydrogen peroxide solution are mixed 1: 2 for about 20 minutes. .
When the first sacrificial layer or the second sacrificial layer is silicon dioxide, buffered hydrofluoric acid in which ammonium fluoride is mixed at a ratio of 7 to the 49% hydrofluoric acid aqueous solution 1 is used. When the first sacrificial layer or the second sacrificial layer is silicon, alkali metal hydroxide such as phosphoric acid, KOH, NaOH, CsOH, NH ₄ OH, hydrazine, EPD (ethylenediamine, pyrocatechol,
Water mixture), TMAH, IPA, NMD3 solution or the like.

When drying after wet etching, to prevent buckling of the microstructure due to capillary action,
Rinsing is performed using an organic solvent having a low viscosity (for example, cyclohexane), or drying is performed under conditions of low temperature and low pressure, or a combination of both.

The first sacrificial layer or the second sacrificial layer is formed of F ₂ or XeF under high pressure conditions such as atmospheric pressure.
₂ can be removed by dry etching.

Furthermore, in order to prevent buckling of the microstructure due to capillary action occurring in the space after the first sacrificial layer or the second sacrificial layer is removed, plasma treatment for imparting water repellency to the surface of the microstructure can be performed.
By using such a process to etch away the first sacrificial layer 206 and the second sacrificial layer 208, a space 240 is created, and the microstructure 219 can be manufactured.

In the method for manufacturing the microstructure 219 described above, an appropriate combination of a material for the structural layer 207, a material for the first sacrificial layer 206, a material for the second sacrificial layer 208, and an etchant for removing the sacrificial layer is used. Must be selected. For example, when the etching agent is determined to be a specific one, the first sacrificial layer 2 is formed using a material having a higher etching rate than the material of the structural layer 207.
06 and the second sacrificial layer 208 may be formed.

Furthermore, the first sacrificial layer 206 and the second sacrificial layer 208 are formed of different materials,
If etching cannot be performed with the same etching agent, the sacrificial layer must be etched twice. In this case, a layer that is not removed but is in contact with the etchant (for example, the structural layer 20
7 and the second insulating layer 214) must be fully considered.

Further, as in this embodiment, a microstructure including a flexible movable part with high strength can be manufactured by manufacturing a structure layer of a microstructure with a conductive layer included in a gate electrode.

When the structural layer 207 and the second sacrificial layer 208 are formed by the above steps and the sacrificial layer is removed by etching, the second insulating layer 214 remains adhered to the tapered portion of the structural layer 207 (FIG. 8C
) 220). This can be used as a temporary support for preventing buckling of the structural layer 207 when the sacrifice layer is etched away to form the microstructure 219.

When the sacrificial layer is removed by wet etching, the etching solution is used as the structural layer 20.
7 and the first insulating layer 205, and the structural layer 207 and the first insulating layer 205 are attached (ie, buckled) by capillary action. To prevent this, the second insulating layer 214
By this, a support can be produced.

The area where the taper of the structural layer 207 is bonded to the second insulating layer 214 is about 100 nm square to 1 μm square, and the above-mentioned adhesion can be prevented by the support of the second insulating layer 214. However, when the structural layer 207 is moved and used, a support is not necessary. Here, when charges having different polarities are imparted between the semiconductor layer 203 and the structural layer 207 of the microstructure 219, that is, when a voltage is applied, the structural layer 207 is attracted to the semiconductor layer 203 side by electrostatic force and moves downward. Deflection, the support and the structural layer 207 can be separated. This is because the support and the structural layer 207 are bonded to each other with a minute area of about 100 nm square to 1 μm square.

By manufacturing the microstructure 219 using the support in this manner, buckling of the structural layer 207 can be prevented.

Further, in the above process, by changing part of the process or adding another process, microstructures and semiconductor elements having various structures can be manufactured.

For example, in the above process, the second sacrificial layer 208 is removed by etching to form only the structural layer 207; however, a microstructure can be manufactured without removing the second sacrificial layer 208 by etching (FIG. 8 (D) (E)). In this case, only the first sacrificial layer 206 needs to be removed by etching, and the second contact hole 218 for etching away the second sacrificial layer 208 is removed.
Does not have to be formed. By etching away the first sacrificial layer 206, the space 24 is removed.
2 is produced.

Further, the second sacrificial layer 2 is formed on the first sacrificial layer 206 using the same material as that of the first sacrificial layer 206.
21 can be formed, and then a fourth conductive layer 222 can be sequentially stacked (FIGS. 9A and 9B).
(See (C)). Then, by removing the first sacrificial layer 206 and the second sacrificial layer 221 by etching, a space 244 is generated, and the fourth conductive layer 222 and the second insulating layer 214 are formed.
A microstructure that becomes a structural layer can be manufactured. Through the above method, a capacitor 224 having a space below, a microstructure 224 having functions such as a cantilever and a switch can be manufactured (see FIGS. 9D and 9E).

At this time, the contact hole 223 for etching the sacrificial layer can be formed at the same time as the first contact hole 215 is formed. Alternatively, the contact hole 223 may be formed after the third conductive layer 216 for forming the wiring is formed. The shape of the structural layer forming the microstructure can be determined by the shape of the contact hole 223.

In the above example, the first sacrificial layer 206 and the second sacrificial layer 221 are stacked. However, a single sacrificial layer can be formed without forming the first sacrificial layer 206. It is. Further, in the above example, the first sacrificial layer 206 and the second sacrificial layer 221 are formed of the same material and simultaneously the sacrificial layer is etched away. However, the present invention is not limited to this example. For example, the first sacrificial layer 206 and the second sacrificial layer 221 can be formed using different materials, etched in multiple steps, and removed.

In addition, the counter substrate 225 can be attached to a semiconductor device manufactured over the substrate 201 in order to protect the microstructures 219 and 224 (see FIG. 10). In the case where the counter substrate 225 is attached, a third conductive layer 216 for forming a wiring is formed, and then a second insulating layer 226 is formed on the top surface of the substrate 201 and etched into an arbitrary shape. (Here, the second insulating layer 21
4 is a first insulating layer. At this time, the second insulating layer 226 is patterned so that the sacrificial layer and the structural layer to be a microstructure are exposed. After that, the sacrificial layer is removed by etching, so that a microstructure having the space 246 can be manufactured. Space 246 shown in FIG.
Has an open area at one end thereof.

Next, the counter substrate 225 for bonding is described. A third insulating layer 227 is formed in a portion facing the second insulating layer 226 formed over the substrate 201 in order not to destroy the microstructure by attaching the counter substrate 225. (Fig. 10 (
A)). An insulating layer is not formed in a portion facing the microstructure formed over the substrate 201 and a gap is formed between the substrates. Therefore, the microstructure is destroyed when the substrate 201 and the counter substrate 225 are attached to each other. This is preferable.

The fifth conductive layer 228, an antenna, or the like can be formed over the counter substrate 225 (see FIG. 10B). The fifth conductive layer 228 is patterned into an arbitrary shape and corresponds to a wiring constituting a circuit of the semiconductor device. In this case, a sixth conductive layer that forms a wiring for connecting to the first wiring (herein, the third conductive layer 216) on the second insulating layer 226 formed on the substrate 201. 229 is formed. Then, the substrate 201 and the counter substrate 225 can be attached so that the sixth conductive layer 229 and the fifth conductive layer 228 are electrically connected.

Note that when the conductive layer constituting the circuit of the semiconductor device is formed on the counter substrate, the substrate and the counter substrate are bonded to each other by combining the conductive layer formed on the substrate and the conductive layer formed on the counter substrate. It is desirable to use an anisotropic conductive material for electrical connection. Here, the anisotropic conductive material is an anisotropic conductive paste (ACP: Anisotropic Conductive Pa).
steel) or anisotropic conductive film (ACF: Anisotropic Con)
A material obtained by thermally curing (ductive Film) can be used. The anisotropic conductive material has conductivity only in a specific direction (here, a direction perpendicular to the substrate). An anisotropic conductive paste is called a binder layer and has a structure in which particles having a conductive surface (hereinafter referred to as conductive particles) are dispersed in a layer whose main component is an adhesive. The anisotropic conductive film has a structure in which particles having a conductive surface (hereinafter referred to as conductive particles) are dispersed in a thermosetting or thermoplastic resin film. Note that particles having a conductive surface are obtained by plating a spherical resin with nickel (Ni), gold (Au), or the like. Insulating particles made of silica or the like may be mixed in order to prevent an electrical short circuit between the conductive particles at unnecessary portions. In the case where only the insulating layer is formed over the counter substrate, the substrate and the counter substrate can be bonded to each other using an adhesive having no conductivity.

At this time, in the same manner as described above, the microstructures 219 and 2 formed on the substrate 201 are used.
24, a portion that does not face the microstructure and a connection portion between the fifth conductive layer 228 and the sixth conductive layer 229 form a third insulating layer 227, and the counter substrate 225 has the microstructure. It is desirable not to touch 219,224. Further, the fifth conductive layer 228 may be formed only on the third insulating layer 227 or may be formed on the upper and lower portions of the third insulating layer 227 and electrically connected to each other. Good (see FIG. 10B).

Further, the semiconductor device manufactured through the above steps can be peeled from the substrate 201 and attached to another substrate or an object. For example, a semiconductor device can be manufactured over a glass substrate and then transferred to a flexible substrate such as a plastic that is thinner and softer than glass.

In the case where the semiconductor device is peeled from the substrate 201, the peeling layer 23 is formed when the base film 202 is formed.
0 is formed (see FIG. 11A). The peeling layer 230 can be formed below the base film or between the stacked base films. Then, after forming the third conductive layer 216 in the above process, the semiconductor device is peeled from the substrate before the second contact holes 217 and 218 for etching the sacrificial layer are formed.

There are various methods for peeling, but an example is shown here. First, the opening 231 is formed so that the peeling layer 230 is exposed, an etchant is introduced into the opening 231, and the peeling layer 230 is partially removed (see FIG. 11B). Next, the substrate 23 for peeling from the upper surface direction of the substrate 201.
2 and the semiconductor element and the microstructure are separated from the substrate 201 with the separation layer 230 as a boundary,
Transfer to substrate 232. Next, the flexible substrate 233 is bonded to the side where the semiconductor element and the microstructure are in contact with the substrate 201. Then, a substrate 232 for peeling attached from above.
By peeling off the substrate, the substrate can be transposed.

Then, a contact hole is formed so that the sacrificial layer is exposed, and the sacrificial layer is etched away, whereby a microstructure is manufactured. In order to protect the third conductive layer 216 and the like at the time of peeling, a protective film may be formed over the wiring.

Further, when it is necessary to protect the microstructure, the counter substrate 225 described above can be attached.

In this embodiment mode, a method for transferring the semiconductor element and the microstructure to another substrate 233 after etching the separation layer 230 from the opening 231 is described; however, the present invention is not limited to this example. For example, after the peeling layer 230 is removed only by an etching process, the semiconductor element and the microstructure are transferred to another substrate 233, or the substrate 20 is not provided without the peeling layer 230.
1 A substrate 232 for peeling is attached from the upper surface to attach a semiconductor element and a microstructure to the substrate 20.
There is a method of peeling from 1. Further, there is a method of polishing the substrate 201 from the back surface to obtain a semiconductor element and a microstructure, and these methods can be combined appropriately. When a process of transferring the substrate 201 to another substrate 233 using a method other than polishing the substrate 201 from the back surface is used, there is an advantage that the substrate 201 can be reused.

As described above, a thin, soft, and small semiconductor device can be manufactured by peeling the semiconductor element and the microstructure formed over the substrate 201 and attaching them to the flexible substrate 233.

When crystallization is performed by laser crystallization or a combination of a metal and a laser as in the above-described process, the crystallization can be performed at a lower temperature than crystallization by heat alone, so that the range of materials that can be used in the process is widened. For example, when the semiconductor layer is crystallized only by heating, 1000 ° C.
It is necessary to perform heating for about 1 hour at a temperature of about a glass substrate that is vulnerable to heat and a melting point of 10
A metal having a temperature of 00 ° C. or lower cannot be used. However, a glass substrate having a strain point of 593 ° C. can be used by the process using the metal.

In addition, compared with a semiconductor layer only by thermal crystallization, the semiconductor layer manufactured by the above process has continuous crystal grain boundaries, so that the covalent bond is not interrupted. Therefore, stress concentration caused by unpaired bonds between grain boundaries does not occur, and as a result, the fracture stress becomes higher than that of general polycrystalline silicon.

Amorphous silicon generally has internal residual stress after film formation. For this reason, it is difficult to form a thick film. On the other hand, in the polycrystalline silicon manufactured by the above process, the internal stress is relaxed and the film can be formed at a lower temperature process, so that a semiconductor layer having an arbitrary thickness can be obtained by repeating the film formation and crystallization. It is also possible to pattern other materials on the semiconductor layer and further form a semiconductor layer thereon.

Further, it is known that a silicon alloy such as nickel silicide is generally high in strength. By selectively leaving a metal used for crystallization in the semiconductor layer and applying an appropriate heat treatment, a microstructure 219 that is harder and has higher conductivity can be manufactured. Therefore,
As described in this embodiment mode, the semiconductor layer is excellent when it is used as an electrode under the microstructure.

In addition, according to the present invention, a microstructure and a semiconductor element are manufactured over the same substrate, so that a semiconductor device that does not require assembly or a package and does not require manufacturing costs can be provided.

Note that this embodiment mode can be freely combined with the above embodiment modes.

(Embodiment 3)
In this embodiment, an example of the semiconductor device described in the above embodiment will be described. In the semiconductor device of the present invention, the sensor device 301 can be formed using a sensing element manufactured using a microstructure.

FIG. 12A illustrates a structure of a sensor device 301 which is one embodiment of the semiconductor device of the present invention. The sensor device 301 of this embodiment includes an electric circuit portion 302 having a semiconductor element and a structure portion 303 which is formed using a microstructure.

The structure body 303 includes a detection element 304 configured by a microstructure that detects external pressure, substance concentration, gas or liquid flow rate, and the like.

The electric circuit unit 302 includes an A / D conversion circuit 305, a control circuit 306, and an interface 307.
And a memory 308 and the like.

The A / D conversion circuit 305 converts information transmitted from the detection element into a digital signal. The control circuit controls the A / D conversion circuit and stores the digital signal in the memory. The interface 307 receives drive power from the external control device 310, receives a control signal, transmits information obtained by the sensor device 301 to the external control device 310, and the like.
The memory stores information obtained, information unique to the sensor device, and the like.

In addition, the electric circuit portion 302 can include an amplifier circuit that amplifies a signal received from the structure portion 303, a central processing circuit for processing information obtained by the structure portion 303, and the like.

The external control device 310 transmits a signal for controlling the sensor device 301, and the sensor device 30.
An operation such as receiving information obtained by 1 or supplying drive power to the sensor device is performed.

The sensor device 301 having the above-described configuration can detect external pressure, substance concentration, gas or liquid flow rate, temperature, and the like. In addition, since the sensor device has a central processing arithmetic circuit, it is also possible to realize a sensor device that processes detected information in the sensor device and generates and outputs a control signal for controlling other devices. is there.

FIG. 12B illustrates a structural example of the detection element 304 with a cross-sectional view. A detection element 304 illustrated in FIG. 12B includes a second conductive layer 321 and a first conductive layer 3 which is a structural layer below the base film.
20 and constitutes a capacity. A space 322 is provided below the first conductive layer 320.
Furthermore, since the first conductive layer 320 is moved by receiving an electrostatic force, pressure, or the like, the sensing element 304 is moved.
Is a variable capacitance in which the distance between the first conductive layer and the second conductive layer changes.

By using this structure, the detection element 304 can be used as a pressure detection element in which the first conductive layer 320 is moved by pressure.

In addition, in the detection element 304 illustrated in FIG. 12B, the first conductive layer 320 can be manufactured by stacking two kinds of substances having different coefficients of thermal expansion. In this case, the first conductive layer 320
Can be moved by a change in temperature, the sensing element 304 can be used as a temperature sensing element.

The present invention is not limited to the above configuration example. That is, in this embodiment, the sensor device includes an electric circuit that has a semiconductor element and controls the microstructure, and a detection element that is configured by the microstructure and that is controlled by the electric circuit and detects some physical quantity. It is characterized by that. Further, the sensor device is manufactured using the manufacturing method described in the above embodiment mode.

Note that this embodiment mode can be freely combined with the above embodiment modes.

(Embodiment 4)
In this embodiment, a specific example of the semiconductor device described in the above embodiment will be described. The semiconductor device of the present invention can constitute a memory device having a microstructure in a memory element. In this embodiment, an example of a memory device in which a peripheral circuit such as a decoder is formed using a semiconductor element and the inside of a memory cell is formed using a microstructure.

FIG. 13 illustrates a structure of a memory device 401 which is one embodiment of the semiconductor device of the present invention.

The storage device 401 includes a memory cell array 402, decoders 403 and 404, and a selector 405.
And a read / write circuit 406. Decoders 403 and 404, selector 40
For the configuration of 5, a known technique can be used.

The memory cell 409 includes, for example, a switch element 407 and a storage element 4 that control the storage element.
08 can be included. A memory device 401 described in this embodiment is characterized in that the switch element 407 and / or the memory element 408 are formed using a microstructure.

FIG. 14 shows a configuration example of the memory cell 409. FIG. 14A is a circuit diagram of the memory cell 409.
FIG. 14B shows a cross-sectional view of the structure.

As shown in FIG. 14A, the memory cell 409 includes a switch element 407 including a transistor 410 and a memory element 408 including a microstructure.

As shown in FIG. 14B, the memory element 408 is a microstructure manufactured using the manufacturing method described in Embodiment 1 or 2. The memory element 408 includes a capacitor having a first conductive layer under a base film and a second conductive layer that is a structural layer. The second conductive layer is connected to one of the two high concentration impurity regions of the switch element 407.

The first conductive layer is connected in common to the memory elements 408 of all the memory cells 409 included in the memory device 401. The first conductive layer applies a common potential to all the memory elements when reading data from and writing data to the memory device, and serves as a common electrode 411.

FIG. 15 illustrates an example of a memory cell 409 including a switch element 407 and a memory element 408 which are manufactured using a microstructure. FIG. 15 is a perspective view showing the structure of the memory cell 409.

For the switch element 407 and the memory element 408, the manufacturing method described in Embodiment 1 or 2 is used. The switch element 407 is a microstructure that functions as a switch having a structure in which cantilever beams are combined, and the memory element 408 is a microstructure that functions as a capacitor having a beam structure.

Here, the structure of the switch element 407 will be described. In the switch element 407, the sacrificial layer 420 and the structural layer 421 are stacked on the substrate, and it is only necessary that the lower part of the movable cantilever 422 is etched. In addition, the structure layer 421 includes a control electrode 423 and a conductor 424.

A switch manufactured using a microstructure has an advantage that a signal transmission path through the switch is completely insulated when the switch is off. Furthermore, there is an advantage that the control system for controlling on / off of the switch can be insulated from the signal transmission path.

A storage device having the above structure is a volatile memory, typically a DRAM (Dynamic
Random Access Memory). Known techniques can be used for peripheral circuit configurations and driving methods.

The micro structure constituting the memory cell is advantageous in that the switch response speed is high and a large force is not required for driving because the scaling law is applied by manufacturing the micro structure in a micro size (for example, in μm units). . Further, by manufacturing the switch element 407 with a microstructure, the selected memory element 408 can be completely insulated, and the memory device 401 with low power consumption can be realized.

Note that this embodiment mode can be freely combined with the above embodiment modes.

(Embodiment 5)
In this embodiment, an example of the semiconductor device described in the above embodiment will be described.

The semiconductor device of the present invention can be configured as, for example, a separation device that separates a specific substance from a mixture. The sorting apparatus will be described below.

FIG. 16 shows a basic configuration example of the sorting apparatus according to the present embodiment. Here, as an example of the separation apparatus, a separation apparatus that separates a gas of a specific substance from a mixed gas of two or more kinds of substances will be described.

The sorting device 501 is roughly divided into an electric circuit portion 502 and a structure portion 503, and the structure portion 503.
Has a detecting means 504 and a plurality of opening / closing means 505. The electric circuit unit 502 includes a signal processing unit 506, an opening / closing control unit 507, an information storage unit 508, and a communication unit 509.

Here, the detection means 504 and the opening / closing means 505 are constituted by a micro structure having a size of about a gas molecule to be sorted. One detection means 504 is provided adjacent to one opening / closing means 505 and detects what kind of substance is present near the opening / closing means 505. The opening / closing means 505 has a passage opening, receives a control signal from the opening / closing control means 507, and opens the passage opening only when a specific substance exists nearby to allow the specific substance to pass therethrough.

The signal processing unit 506 processes the signal transmitted from the detection unit 504 by amplification, A / D conversion, and the like, and transmits the processed signal to the opening / closing control unit 507. The opening / closing control means 507 controls the opening / closing means 505 based on the signal transmitted from the detection means 504. The information storage means 508 includes the sorting device 5
A program file for operating 01, information unique to the sorting apparatus 501 and the like are stored. A communication unit 509 communicates with an external control device 510.

The external control device 510 includes a communication unit 511, an information processing unit 512, a display unit 513, an input unit 514, and the like.

The communication unit 511 transmits a signal for controlling the sorting device 501, receives information obtained by the sorting device 501, supplies driving power to the sorting device 501, and the like. Information processing means 51
2 performs processing for processing information received from the sorting device 501, processing for transmitting information input from the input means to the sorting device 501, and the like. The display unit 513 displays information obtained from the sorting device 501, the operation status of the sorting device 501, and the like. The input means 514 provides a user with a means for inputting information.

FIG. 16B shows an embodiment in which the sorting apparatus 501 is used. Sorting device 50 having the above-described configuration
1 is disposed between the mixed material layer 520 and the specific material layer 521. When the sorting device 501 receives information from the external control device 510 such as which substance is to be sorted, the detection unit 5
04 detects what kind of substance exists in the immediate vicinity of the opening / closing means 505. Next, the signal processing means 506 processes the detection signal and transmits it to the open / close control means 507. The opening / closing control means 507 controls the opening / closing means 505 so as to open the passage only when there is a substance to be separated in the immediate vicinity of the opening / closing means 505. The opening / closing means 505 is an opening / closing control means 507.
Under the control from, only the substance to be separated is allowed to pass through the passage.

By the above operation, the separation device 501 can separate a gas of a specific substance from two or more kinds of mixed gases. Further, the separation device 501 is not limited to only gas separation. By using the above configuration, for example, it is possible to configure as a device for sorting specific cells. As an example, control can be performed so that only cells that fluoresce when irradiated with ultraviolet light are separated. Furthermore, it is possible to realize a separation apparatus having functions such as separation of only particles having fine grain boundaries, for example, particles containing radioactive substances, or separation of only magnetic ore particles.

The present invention can provide a separation system that includes the separation device 501, the mixed material layer 520, the specific material layer 521, and the external control device 510 and separates a specific material from the mixed material.

Note that this embodiment mode can be freely combined with the above embodiment modes.

The structural layer of the semiconductor device of the present invention can be formed, for example, by stacking a layer having polycrystalline silicon crystallized by the above process and a layer having amorphous silicon. Like the layer having polycrystalline silicon and the layer having amorphous silicon described above, silicon layers having different crystal states have different mechanical characteristics. Therefore, by stacking or forming a structure layer in a selective region, microstructures corresponding to various uses can be manufactured. In this example, the results of measuring the mechanical properties of these layers are shown.

In order to investigate the difference in the mechanical properties of silicon layers with different crystal states, the composite elastic modulus and indentation hardness of the layer having amorphous silicon and the layer having polycrystalline silicon formed by CVD are used. Measurements were made. Here, the layer having polycrystalline silicon is obtained by laser crystallization of a layer having amorphous silicon using a metal catalyst.

The layer containing amorphous silicon used for the sample is 50 nm thick on the quartz substrate as an underlayer.
A silicon nitride layer and a silicon oxide layer having a thickness of 100 nm were formed by a CVD method, and an amorphous silicon layer was formed on the base layer by the CVD method.

The layer having polycrystalline silicon used for the sample was formed by crystallizing a layer having amorphous silicon formed in the same manner as described above using a continuous wave laser. Here, the energy density of the laser beam used for crystallization is 9 to 9.5 W / cm ² , and the scanning speed is 35 cm / se.
c.

Here, the layer containing amorphous silicon used for the sample was formed with a thickness of 66 nm, and the thickness of the layer containing polycrystalline silicon crystallized by laser irradiation was about 60 nm.

The measurement was performed by nanoindentation measurement in which a triangular pyramid indenter was pushed into the sample. The measurement conditions were a single indentation of the indenter, and the indenter used was Berkov made of diamond.
It is an ich indenter. Therefore, the elastic modulus of the indenter is about 1000 GPa and the Poisson's ratio is about 0.1.
1.

The measured composite elastic modulus is an elastic modulus obtained by combining the elastic modulus of the sample and the indenter expressed by the following mathematical formula (1). In Equation (1), Er is the composite elastic modulus, E is the Young's modulus, and ν is the Poisson's ratio. In addition, the first term (a term indicated by sample) in the formula (1) is a term contributed by the elastic modulus of the sample, and the second term (a term indicated by indenter) is a term contributed by the elastic modulus of the indenter.

As shown in Equation (1), the composite elastic modulus is obtained as the sum of the first term contributed by the elastic modulus of the sample and the second term contributed by the elastic modulus of the indenter. However, since the elastic modulus of the indenter is much larger than that of the sample, the second term can be ignored, and the composite elastic modulus approximately represents the elastic modulus of the sample.

The indentation hardness is hardness measured by an indentation method, and is obtained by dividing the maximum press-fit weight of the indenter by the projected area at the time of maximum press-fit. Here, the projected area at the time of press-fitting is determined by the geometric shape of the indenter and the contact depth when the indenter pushes the sample. By multiplying this indentation hardness by 76, it can be handled equivalent to the Vickers hardness generally used as an index of hardness.

Table 1 shows the measurement results of the composite elastic modulus and indentation hardness of the layer having polycrystalline silicon and the layer having amorphous silicon. The result has shown the average value of 3 times of measurement results.

From the results shown in Table 1, the layer having polycrystalline silicon has a higher elastic modulus than the layer having amorphous silicon. That is, when a force that bends the structure is applied, the layer having polycrystalline silicon is more resistant to breakage due to bending than the layer having amorphous silicon.

Further, the results shown in Table 1 indicate that the layer having polycrystalline silicon is harder than the layer having amorphous silicon.

By stacking semiconductor layers having different elastic moduli and hardness in this manner, a microstructure that has both flexibility and resistance to bending force can be manufactured. For example, by stacking the above-described layers, even if breakdown occurs from a crystal defect of a layer including polycrystalline silicon, the breakdown is difficult to propagate to the layer including amorphous silicon, and thus the breakdown can be stopped. Thus, the balance between flexibility and hardness can be determined by the ratio of the thicknesses of the layers to be laminated.

In this way, a microstructure having a structural layer having desired properties such as flexibility, flexibility, or conductivity by laminating or partially forming silicon layers having different properties or silicon compound layers. The body can be made.

6A and 6B illustrate a semiconductor device of the present invention. 8A and 8B illustrate a method for manufacturing a semiconductor device of the present invention. 8A and 8B illustrate a method for manufacturing a semiconductor device of the present invention. 8A and 8B illustrate a method for manufacturing a semiconductor device of the present invention. 8A and 8B illustrate a method for manufacturing a semiconductor device of the present invention. 8A and 8B illustrate a method for manufacturing a semiconductor device of the present invention. 8A and 8B illustrate a method for manufacturing a semiconductor device of the present invention. 8A and 8B illustrate a method for manufacturing a semiconductor device of the present invention. 8A and 8B illustrate a method for manufacturing a semiconductor device of the present invention. 8A and 8B illustrate a method for manufacturing a semiconductor device of the present invention. 8A and 8B illustrate a method for manufacturing a semiconductor device of the present invention. 6A and 6B illustrate one embodiment of a semiconductor device of the present invention. FIG. 9 illustrates a structure of a memory cell. FIG. 9 illustrates a structure of a memory cell. 6A and 6B illustrate one embodiment of a semiconductor device of the present invention. 6A and 6B illustrate one embodiment of a semiconductor device of the present invention.

Claims (15)

Having an electrical circuit and a microstructure provided on a substrate;
The electrical circuit has a semiconductor element;
The microstructure includes a layer including polycrystalline silicon that is thermally crystallized or laser-crystallized using a metal. An electrical circuit provided on a substrate, a conductive layer, and a microstructure,
The electrical circuit has a semiconductor element;
The electrical circuit and the microstructure are electrically connected by the conductive layer;
The microstructure includes a layer including polycrystalline silicon that is thermally crystallized or laser-crystallized using a metal. An electric circuit provided on the substrate, a microstructure, and a counter substrate provided to face the substrate;
The electrical circuit includes a semiconductor element, and the microstructure includes a layer including polycrystalline silicon that is thermally crystallized or laser crystallized using a metal,
A semiconductor device, wherein an insulating layer is provided on a part of the counter substrate that does not face the microstructure. An electric circuit provided on the substrate, a conductive layer, a microstructure, and a counter substrate provided to face the substrate;
The electrical circuit has a semiconductor element;
The electrical circuit and the microstructure are electrically connected by the conductive layer;
The microstructure has a layer including polycrystalline silicon that is thermally crystallized or laser crystallized using a metal;
A semiconductor device, wherein an insulating layer is provided on a part of the counter substrate that does not face the microstructure. An electric circuit provided on the substrate, a first conductive layer, a microstructure, and a counter substrate provided to face the substrate;
The electrical circuit has a semiconductor element;
The microstructure has a layer including polycrystalline silicon that is thermally crystallized or laser crystallized using a metal;
An insulating layer is provided on a part of the counter substrate that does not face the microstructure,
A second conductive layer is provided on the insulating layer;
The semiconductor device, wherein the electric circuit and the microstructure are electrically connected by the first conductive layer or the second conductive layer. In claim 5,
The semiconductor device, wherein the first conductive layer and the second conductive layer are electrically connected via an anisotropic conductive material. In any one of Claims 1 thru | or 6,
A semiconductor device, wherein a first space is provided between the substrate and the layer having polycrystalline silicon. In any one of Claims 1 thru | or 6,
A first space is provided between the substrate and the layer comprising polycrystalline silicon;
A semiconductor device, wherein a second space is provided between the layer having polycrystalline silicon and the layer provided on the layer having polycrystalline silicon. In claim 7 or claim 8,
The microstructure includes a third conductive layer between the substrate and the first space. In claim 7,
The microstructure has a third conductive layer between the substrate and the first space,
A semiconductor device, wherein a second space is provided between the layer having polycrystalline silicon and the layer provided on the layer having polycrystalline silicon. In any one of Claims 1 thru | or 6,
The microstructure has a fourth conductive layer provided on the layer having polycrystalline silicon,
A semiconductor device, wherein a first space is provided between the layer having polycrystalline silicon and the fourth conductive layer. In claim 11,
The microstructure has an insulating layer having an organic material or an inorganic material provided on the fourth conductive layer,
A semiconductor device, wherein a second space is provided between the fourth conductive layer and the insulating layer. In any one of Claims 7 to 11,
The semiconductor device is characterized in that the first space is generated by etching a sacrificial layer formed using a material having a metal element, a metal compound, silicon, silicon oxide, or silicon nitride. . In any one of Claims 1 thru | or 13,
The semiconductor device is characterized in that the metal is selectively added to a layer to be the layer containing polycrystalline silicon. In any one of Claims 1 thru | or 14,
2. The semiconductor device according to claim 1, wherein the layer having polycrystalline silicon has a stacked structure of the polycrystalline silicon and amorphous silicon.

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