JPH04359448A - Semiconductor device and its estimation method - Google Patents

Abstract

PURPOSE:To estimate accurately a slanting ion implantation technique and a rotational ion implantation technique used in a semiconductor manufacturing process. CONSTITUTION:A semiconductor device is formed for estimating an ion implantation technique used in a semiconductor manufacturing process. The semiconductor device comprises two electrodes 11 formed on a semiconductor substrate and made of a conductive material, a coupling part 12 having a projecting shape for connecting the two electrodes and made of an insulating material 12' at least at the surface thereof, and a semiconductor film 13 for connecting the two electrodes through one of the sidewall of the coupling part 12.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a semiconductor device and an evaluation method thereof for evaluating ion implantation techniques during the manufacture of semiconductor devices, and in particular to evaluation methods for ion implantation techniques such as oblique ion implantation techniques and rotational ion implantation techniques. The present invention relates to a semiconductor device used and a method for evaluating the same.

0002

2. Description of the Related Art Conventionally, as a method for evaluating ion implantation techniques used in semiconductor device manufacturing processes, ions are usually implanted into the surface of a semiconductor substrate, and then the resistance of the surface of the substrate is measured.

On the other hand, as recent ion implantation techniques, oblique ion implantation techniques that allow the ion implantation angle to be freely set with respect to the semiconductor substrate surface, and rotational ion implantation techniques that allow ion implantation to be performed while rotating the semiconductor substrate have been developed. has been done.

By the way, when the above-mentioned conventional evaluation method is applied to evaluate the above-mentioned oblique ion implantation technique, the change in the ion implantation amount due to a slight change in the ion implantation angle (the change in the resistance of the substrate surface) Since the amount of change) was small, it was difficult to accurately evaluate the relationship between the ion implantation angle and the ion implantation amount. In addition, when the conventional evaluation method described above is used to evaluate the rotational ion implantation technique, the amount of ion implantation changes little with respect to a slight change in the direction of ion implantation in the in-plane direction of the semiconductor substrate. Therefore, it has been difficult to accurately evaluate the relationship between the ion implantation direction and the ion implantation amount.

[0005]

As described above, the conventional semiconductor device evaluation method has a problem in that it is difficult to accurately evaluate oblique ion implantation techniques and rotational ion implantation techniques.

The present invention has been made to solve the above problems, and provides a semiconductor device and an evaluation method thereof that can accurately evaluate oblique ion implantation technology and rotational ion implantation technology used in semiconductor manufacturing processes. The purpose is to

[0007]

[Means for Solving the Problems] The present invention provides two electrode portions made of a conductor formed on a semiconductor substrate in a semiconductor device formed to evaluate ion implantation technology used in a semiconductor manufacturing process. a connecting portion formed in a convex shape and having at least a surface made of an insulator so as to connect the two electrode portions; and a connecting portion formed such that one side wall of the connecting portion connects the two electrode portions. The semiconductor film is characterized by comprising:

The present invention also provides a semiconductor device evaluation method for evaluating ion implantation technology used in a semiconductor manufacturing process, in which two electrode portions made of a conductor formed on a semiconductor substrate and A convex connecting part formed to connect the electrode parts and at least a surface of which is made of an insulator, and a semiconductor film formed on one side wall of the connecting part to connect the two electrode parts. the steps of manufacturing a semiconductor device, implanting ions into the semiconductor film of the semiconductor device and activating the implanted ions, and measuring a resistance value between the two electrode parts. It is characterized by

[0009]

[Operation] When ions are implanted into the semiconductor film formed on the side wall of the convex connecting portion and then the implanted ions are activated, the resistance value between the two electrode portions is determined depending on the amount of ion implantation. When ions are implanted using oblique ion implantation technique,
Since the change in the amount of ion implantation (the amount of change in the resistance value) caused by a slight change in the ion implantation angle is large, by measuring the resistance value between the electrode parts, it is possible to determine the relationship between the ion implantation angle and the amount of ion implantation, and to determine the relationship between the ion implantation angle and the amount of ion implantation in the semiconductor film. It becomes possible to accurately evaluate the relationship between the implantation amount and the change in the in-plane direction of the substrate due to ion implantation from the direction in which the substrate is facing.

0010

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a portion of a first embodiment of a semiconductor device formed to evaluate ion implantation techniques used in semiconductor manufacturing processes.

Reference numerals 11 denote two electrode portions formed on a semiconductor substrate, the surfaces of each of which are covered with a conductor (for example, a polycrystalline silicon film). Reference numeral 12 denotes a connecting portion formed in a convex shape on the semiconductor substrate so as to connect these two electrode portions 11, and at least the surface thereof is made of an insulator 12'. Made of oxide film. 13 is a semiconductor film formed on one side wall of this connecting portion 12, and has a thickness of, for example, 400 mm.
It is made of a polycrystalline silicon film with a thickness of 100 nm and connects the two electrode parts. In this example, the connecting portion 12 is a conductor (a polycrystalline silicon film on the surface) constituting the electrode portion 11.
In other words, both ends of the polycrystalline silicon film of the connecting portion 12 are formed of the same layer formed at the same time as the two electrode portions 1.
1... is connected to the polycrystalline silicon film on the surface. next,
2(a) to (c) regarding the manufacturing process of the above semiconductor device.
).

First, a semiconductor substrate is oxidized, and a silicon oxide film is formed on the surface of the substrate to a thickness of about 1100 nm. Next, RIE (reactive ion etching) is performed, and as shown in FIG. A portion 12 is formed. Next, the entire structure is oxidized to form a silicon oxide film to a thickness of about 100 nm. Next, a semiconductor film, for example a polycrystalline silicon film 13, is deposited to a thickness of about 400 nm.

Next, only the portion where the electrode is to be formed is covered with a resist (not shown), and RIE is performed to form the area shown in FIG. 2(b).
As shown in FIG.
...Etching is performed so as to leave only the surface and the side wall of the connecting portion 12.

Next, after removing the resist, one side wall of the connecting portion 12 is covered with a resist (not shown) so that only one side wall of the connecting portion 12 is exposed, as shown in FIG. 2(c). Perform isotropic etching to remove only the sidewalls. Next, an example of an evaluation method for evaluating an ion implantation technique used in a semiconductor manufacturing process using the above semiconductor device will be described with reference to FIG.

[0015] In the semiconductor device, the two electrode parts 11 on the semiconductor substrate are connected to each other on one side wall of a convex connecting part 12 whose surface is made of an insulator 12'. A polycrystalline silicon film 13 is formed to connect the electrode parts 11. Therefore, after implanting ions into the polycrystalline silicon film 13 on the side wall of the connecting portion,
A silicon oxide film (not shown) was deposited on the entire surface to a thickness of about 300 nm, and was heated at 95 nm in an inert gas atmosphere.
When heat treatment is performed at 0° C. for about 30 minutes to electrically activate the implanted ions, the resistance value between the two electrode portions 11 is determined depending on the amount of ions implanted. Furthermore, by removing only the surface portion of the electrode portion of the silicon oxide film with an ammonium fluoride solution to expose the polycrystalline silicon film 13 on the surface of the electrode portion 11, it is possible to electrically measure the resistance value between the electrode portions 11. become.

When the ions are implanted using an oblique ion implantation technique, the change in the amount of ions implanted (the amount of change in the resistance value) caused by a slight change in the ion implantation angle is large. By measuring the resistance value between the ion implantation angle and the ion implantation amount, it becomes possible to accurately evaluate the relationship between the ion implantation angle and the ion implantation amount. That is, the number d of ions implanted per unit area of the polycrystalline silicon film 13 on the side wall of the connecting portion is expressed by the following equation. d=Dcosθ

Here, θ is the angle formed by the ion implantation direction 32 with respect to the normal 31 of the polycrystalline silicon film 13 on the side wall of the connecting portion, and D is the angle when ions are implanted perpendicularly to the surface of the polycrystalline silicon film on the side wall of the connecting portion. is the number of ions implanted per unit area. From the above equation, the ion implantation amount per unit area depends on the ion implantation angle θ. In particular, when θ=90°, the ion implantation amount largely depends on the ion implantation angle θ.

Furthermore, when the ion implantation is performed, if the in-plane direction of the ion implantation is changed from the direction in which the polycrystalline silicon film 13 on the side wall of the connecting portion faces, the ion implantation direction in the in-plane direction of the semiconductor substrate is changed. Since the change in the ion implantation amount (the amount of change in the resistance value) for a slight change is large, it is possible to accurately evaluate the relationship between the ion implantation direction and the ion implantation amount.

Note that the semiconductor device of the present invention is not limited to the embodiment shown in FIG. 1, and can be implemented in various modifications. For example, if two sets of polycrystalline silicon films for the side walls of the electrode portion and the connecting portion are provided, in which the directions in which the connecting portions are formed in the plane of the semiconductor substrate are orthogonal to each other, each set has a polycrystalline silicon film on the side wall of the connecting portion. It becomes possible to accurately evaluate the relationship between the amount of ion implantation and the change in the in-plane direction of the substrate due to ion implantation from the direction in which the crystalline silicon film is oriented. Similarly, two sets of polycrystalline silicon films for the side walls of the electrode portion and the connecting portion are provided independently with the connecting portions formed in the same direction in the plane of the semiconductor substrate, and each semiconductor film in these two sets is connected to each connecting portion in the two sets. When the ion implantation is performed on different sidewalls of the connecting portion, the relationship between the ion implantation amount and the change in the in-plane direction of the substrate from the direction in which the polycrystalline silicon film on the sidewall of the connecting portion faces is determined for each group. It becomes possible to evaluate accurately.

FIG. 4 shows a part of a semiconductor device according to a second embodiment. In this semiconductor device, four sets of electrode parts 11 and polycrystalline silicon films 13 on the side walls of the connecting part shown in FIG. 1 are formed so as to face in four directions perpendicular to each other. Therefore, when ions are implanted using the rotational ion implantation technique, the polycrystalline silicon film 1 on the side walls of the four connecting parts
It becomes possible to accurately evaluate the relationship between the amount of ion implantation and the change in the in-plane direction of the substrate due to ion implantation from the direction in which 3... are facing, respectively.

FIG. 5 shows a part of a semiconductor device according to a third embodiment. This semiconductor device is different from the semiconductor device shown in FIG. 1 in that a plurality of sets of connecting portions 12 and polycrystalline silicon films 13 on the side walls of the connecting portion are arranged in parallel at intervals between the two electrode portions 11. They are different in how they are formed.

According to this semiconductor device, when ions are implanted into a plurality of (N) polycrystalline silicon films between two electrode portions and the implanted ions are activated, the two electrodes are activated as in each of the above embodiments. The polycrystalline silicon film connecting the parts is 1
The resistance value between the two electrode parts is 1 compared to the case where there are only 1
/N times, so there is an advantage that the resistance value between the electrode parts can be stably measured.

[0023]

As described above, according to the present invention, it is possible to realize a semiconductor device and an evaluation method thereof that can accurately evaluate oblique ion implantation technology and rotational ion implantation technology used in semiconductor manufacturing processes.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a part of a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an example of the manufacturing process of the semiconductor device shown in FIG. 1;

FIG. 3 is a perspective view showing the evaluation method of the present invention.

FIG. 4 is a plan view showing a semiconductor device according to a second embodiment of the present invention.

FIG. 5 is a plan view showing a semiconductor device according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11... Electrode part, 12... Connection part, 12'... Insulator, 13...
semiconductor film.

Claims (6)

[Claims] 1. Two electrode parts made of a conductor formed on a semiconductor substrate; a connecting part formed in a convex shape to connect the two electrode parts and having at least a surface made of an insulator; A semiconductor device comprising: a semiconductor film formed so as to connect the two electrode parts on one side wall of the connecting part. 2. The semiconductor device according to claim 1,
A semiconductor device, wherein the conductor constituting the electrode portion and the semiconductor film on the side wall of the connecting portion are formed at the same time and made of the same layer. 3. The semiconductor device according to claim 1, wherein the two electrode portions, the connecting portions, and the semiconductor film are independently provided in two sets in which the connecting portions are formed in directions perpendicular to each other within the plane of the semiconductor substrate. A semiconductor device characterized by: 4. The semiconductor device according to claim 1, wherein the two electrode portions, the connecting portion, and the semiconductor film are independent in that the connecting portions are formed in the same direction within the plane of the semiconductor substrate. 2. A semiconductor device characterized in that two sets are provided, and each semiconductor film in the two sets is formed on a side wall on a different side of each connecting portion in the two sets. 5. The semiconductor device according to claim 1, wherein a plurality of sets of the connecting portion and the semiconductor film are formed in parallel between the two electrode portions. 6. Two electrode parts made of a conductor formed on a semiconductor substrate, a convex connecting part formed to connect the two electrode parts and having at least a surface made of an insulator, and the above-mentioned 2 electrode parts. manufacturing a semiconductor device including a semiconductor film formed on one side wall of the connecting portion so as to connect two electrode portions; and implanting ions into the semiconductor film of the semiconductor device, and implanting the implanted ions into the semiconductor film of the semiconductor device. 1. A method for evaluating a semiconductor device, comprising the steps of: activating the electrode portion; and measuring a resistance value between the two electrode portions.