JP3203715B2 - Method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a semiconductor device used for a semiconductor integrated circuit formed on a semiconductor substrate, a liquid crystal display device formed on an insulating substrate, and the like.

[0002]

2. Description of the Related Art A conventional method for manufacturing a semiconductor device will be described with reference to FIG. First, as shown in FIG. 2A, an insulating thin film 202 is laminated on a semiconductor substrate 201, and the insulating thin film 202 is opened by photoetching. Is implanted by ion implantation, an amorphous impurity diffusion layer is formed in the semiconductor substrate 201, and then heat treatment is performed to activate and crystallize the impurity diffusion layer 204. 2
05 is formed. Then, as shown in FIG.
A first semiconductor layer 206 is laminated so as to cover the opening 203 and is patterned. Then, the second insulating film 2
07 is stacked on the second insulating film 207 in the same manner as that used for forming the opening 203.
8 is formed, a second semiconductor layer 209 is stacked on the entire surface, and is patterned to obtain the structure shown in FIG. 2C, thereby completing the semiconductor device.

[0003]

In recent years, with the development of semiconductor integrated circuits, there has been a growing demand for higher integration and lower power consumption of semiconductor devices used in semiconductor integrated circuits.

[0004] However, in the above-mentioned conventional technology, some problems are pointed out. One of them is a voltage drop when connecting the semiconductor layers. When the semiconductor layers are connected by the above conventional technique, the connection surface of the semiconductor layer to be connected is a portion where the periodic condition of the semiconductor atoms is disturbed, and there are many lattice defects. When the semiconductor layers including many lattice defects are connected to each other, the above-described lattice defects form trap levels, thereby loading the resistance. Therefore, when a voltage is applied, carriers are trapped by this, and a voltage drop occurs. Happens. Reducing the voltage drop is an important issue for reducing the power consumption and improving the performance of the semiconductor device. As a method for connecting the semiconductor layers, a method using a metal as the wiring layer has been studied. In this case, however, it has been pointed out that the process is complicated and difficult to miniaturize. A method of inserting a compound having a high melting point metal or a semiconductor between semiconductor layers to be connected has also been considered, but also in this case, the complexity of the process is a problem.

The present invention has been made to solve the above-mentioned problems in the prior art, and an object of the present invention is to provide a method of manufacturing a semiconductor device capable of miniaturization, high integration, and high performance. There.

[0006]

According to the present invention, there is provided a process for forming a first amorphous semiconductor layer on an insulating substrate or an insulating thin film, and forming an insulating film on the first amorphous semiconductor layer. Forming and opening a contact hole; forming a second amorphous semiconductor layer on the insulating film; and forming the first amorphous semiconductor layer and the second non-conductive layer through the contact hole. Connecting the first amorphous semiconductor layer and the second amorphous semiconductor layer connected to the first amorphous semiconductor layer by a laser annealing method or an RTA method. It is characterized by the following. Further, the first amorphous semiconductor layer is formed with a first conductivity type, and the second amorphous semiconductor layer is formed with a second conductivity type. Further, the first amorphous semiconductor layer and the second amorphous semiconductor layer are formed with the same conductivity type.

On an insulating substrate or an insulating thin film,
A step of forming a first amorphous semiconductor layer, a step of forming an insulating film on the first amorphous semiconductor layer and opening a contact hole, and a step of forming a second amorphous film on the insulating film. Forming a semiconductor layer and connecting the first amorphous semiconductor layer and the second amorphous semiconductor layer through the contact hole; And crystallization of the second amorphous semiconductor layer connected to the semiconductor device. Further, the method is characterized in that the first amorphous semiconductor layer is formed of a first conductivity type, and the second amorphous semiconductor layer is formed of a second conductivity type. Further, the first amorphous semiconductor layer and the second amorphous semiconductor layer are formed with the same conductivity type.

[0008]

According to the method of manufacturing a semiconductor device of the present invention, an amorphous impurity diffusion layer and an amorphous semiconductor layer in a semiconductor substrate, or a first amorphous semiconductor layer on an insulating substrate or an insulating thin film. By connecting the second amorphous semiconductor layer to the second amorphous semiconductor layer in an amorphous state and then simultaneously crystallization, a semiconductor junction with few crystal defects can be formed. By using a laser annealing method or an RTA method as a method for crystallizing a semiconductor layer, crystallization can be performed in a short time and diffusion of impurities can be suppressed to be small, so that miniaturization is possible. In addition, when crystallization is performed by a laser annealing method or an RTA method, the amorphous semiconductor layer is melted once and then crystallized, so that bonding defects at a bonding portion are further reduced. Therefore,
When the amorphous semiconductor layer or the first amorphous semiconductor layer in the semiconductor substrate is of the first conductivity type and the connected amorphous semiconductor layer is of the second conductivity type, a good PN junction is formed. When both are of the same conductivity type, a trap having few contact points at the joint end face and having good contact characteristics can be formed. Thus, lower power consumption and higher performance of the semiconductor device can be realized.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of a method for manufacturing a semiconductor device according to the present invention.
One will be described in detail with reference to element cross-sectional views for each manufacturing process. First, as shown in FIG.
1, a first insulating thin film 102 is formed, and an opening 103 is formed by a photo-etching method.
3, the impurity ions 104 are introduced and the impurity diffusion layer 1 is introduced.
05 is formed. The insulating thin film 102 is formed of a silicon dioxide film or a silicon nitride film formed by a thermal oxidation method, a thermal nitridation method, a normal pressure CVD method, a low pressure CVD method, a plasma CVD method, an ECR plasma CVD method, a sputtering method, or the like. Are formed by a combination of For the introduction of the impurity ions 104, an ion implantation method such as an ion implantation method or an ion doping method is used. The conductivity type of the amorphous impurity diffusion layer 105 formed in the semiconductor substrate 101 is determined by the introduced impurity ions. Next, as shown in FIG. 1B, a first amorphous semiconductor layer 106 is laminated and patterned on the entire surface to form an amorphous impurity diffusion layer 1 in the semiconductor substrate 101.
05 and the first amorphous semiconductor layer 106 are connected at the opening 103. The first amorphous semiconductor layer 1
06 is a low pressure CVD method, a plasma CVD method or an EC method.
It is formed by an R plasma CVD method or the like. Further, the first amorphous semiconductor layer 106 may be formed of a polycrystalline semiconductor layer and then made amorphous by introducing ions. The conductivity type of the amorphous semiconductor layer 106 is as follows:
Amorphous impurity diffusion layer 105 in the semiconductor substrate 101
Or the opposite conductivity type. afterwards,
After the second insulating thin film 107 is stacked and the opening 108 is formed again by using the photoetching method, the second amorphous semiconductor layer 109 is stacked, and the second amorphous semiconductor layer 109 is stacked at the opening 108. One amorphous semiconductor layer 106 is connected. This state is shown in FIG. The second amorphous semiconductor layer is formed in the same manner as the first amorphous semiconductor layer. afterwards,
As shown in FIG. 1D, a laser beam 110
And crystallization of the amorphous impurity diffusion layer 105, the first amorphous semiconductor layer 106, and the second amorphous semiconductor layer 110 in the semiconductor substrate 101 are all performed simultaneously. Is completed. As a means of crystallization, in addition to the laser annealing method described in this embodiment, there are a thermal annealing method and a lamp annealing method, and the like. Therefore, it is desirable to use a laser annealing method or an RTA method.

In this embodiment, a connection between an amorphous impurity diffusion layer in a substrate and a first amorphous semiconductor layer, and then a first amorphous semiconductor layer and a second amorphous semiconductor Although both connections with layers have been described, it is obvious that only one of the connections may be used, and conversely, the present invention can be applied to a multilayer connection.

[0011]

According to the method of manufacturing a semiconductor device of the present invention, the impurity diffusion layer and the first semiconductor layer, or the first semiconductor layer and the second semiconductor layer in the semiconductor substrate can all be made amorphous. By performing connection in a quality state and then performing crystallization collectively, it is possible to reduce bonding defects at each connection portion. When a laser annealing method is used as the crystallization method, the amorphous semiconductor layer is melted once and then crystallized, so that the junction defects at the connection portion can be further reduced. When the first conductive type amorphous semiconductor layer and the second conductive type amorphous semiconductor layer are connected in this manner, an ideal PN junction can be formed at the connection portion. Further, when amorphous semiconductor layers of the same conductivity type are connected to each other, a junction having a small trap level and a small contact resistance can be formed. That is, a voltage drop at a connection portion of the semiconductor device can be reduced, and low power consumption and high performance of the semiconductor device can be realized. When a laser annealing method or an RTA method is used as a crystallization method, the irradiation time is extremely short, so that diffusion of impurities contained in a semiconductor device formed over the same substrate can be suppressed. In addition, miniaturization of a semiconductor device becomes possible. Therefore, by using the method for manufacturing a semiconductor device of the present invention, miniaturization, low power consumption, and high performance of the semiconductor device can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an element for each manufacturing step in a method for manufacturing a semiconductor device described according to an embodiment of the present invention.

FIG. 2 is a sectional view of an element in each manufacturing process in a conventional semiconductor device manufacturing method.

[Explanation of symbols]

 101, 201 ... semiconductor substrate 102, 202 ... first insulating thin film 103, 108, 203, 208 ... aperture 104, 204 ... impurity ions 105, 205 ... amorphous Impurity diffusion layers 106, 206: first amorphous semiconductor layer 107, 207: second insulating thin film 109, 209: second amorphous semiconductor layer 110: laser beam 205 ..Crystalized impurity diffusion layer 206 ... first semiconductor layer 209 ... second semiconductor layer

Claims (3)

(57) [Claims] 1. The method according to claim 1, wherein the first substrate is provided on an insulating substrate or an insulating thin film.
Forming the first amorphous semiconductor layer, and the first amorphous
Form an insulating film on the semiconductor layer and open a contact hole
And forming a second amorphous semiconductor layer on the insulating film.
Forming the first amorphous layer through the contact hole.
A step of connecting a semiconductor layer and the second amorphous semiconductor layer
And the first by laser annealing or RTA.
Amorphous semiconductor layer and the second amorphous layer connected thereto
Crystallizing the semiconductor layer.
Semiconductor device manufacturing method. 2. The method according to claim 1, wherein the first amorphous semiconductor layer is of a first conductivity type.
And forming the second amorphous semiconductor layer in the second conductivity type.
2. The manufacturing of a semiconductor device according to claim 1, wherein
Construction method. 3. The first amorphous semiconductor layer and the second amorphous semiconductor layer.
Characterized in that the amorphous semiconductor layer is formed with the same conductivity type.
A method for manufacturing a semiconductor device according to claim 1.