JPH09246371A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device and a manufacturing method thereof, where a time required for an element isolation process can be shortened. SOLUTION: An N-type impurity layer 2 is formed on a P-type semiconductor substrate 1, and an insulating film 3 of silicon oxide is formed thereon. Then, a part of the insulating film 3 is removed through a photolithography technique and an etching technique for the formation of an opening at a required position, the semiconductor substrate 1 is anisotropiccally etched with alkali etchant such as potassium hydroxide (KOH) water solution using the insulating film 3 with an opening as a mask to form a groove 4 which reaches to the a P-type semiconductor substrate 1. In succession, P-type impurity ions of baron (B) or the like are implanted only into the groove 4 and thermally diffused to form a P-type impurity region 5, and the P-type semiconductor substrate 1 and the P-type impurity region 5 are connected together to carry out element isolation for the formation of an N-type semiconductor region 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device utilizing junction separation and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIG. 1 is a schematic sectional view showing a semiconductor device according to a conventional example. In a conventional semiconductor device, an n-type impurity layer 2 as a support layer composed of a second conductivity-type impurity layer is formed on a p-type semiconductor substrate 1 which is a first conductivity-type semiconductor substrate, and an element of the n-type impurity layer 2 is formed. Boron (B) at the location where separation is desired
Which is a first conductivity type impurity layer by diffusing p-type impurities such as
A type impurity region 4 is formed to form an n-type semiconductor region 6 which is a second conductivity type semiconductor region, and a surface of the insulating film 3 such as a silicon oxide film is formed. Then, by applying the lowest potential of the entire element to the p-type semiconductor substrate 1 and the p-type impurity region 4, the elements are separated by utilizing the rectifying property of the pn junction.

[0003]

However, in the semiconductor device having the above-described structure, as the thickness of the n-type impurity layer 2 increases, the diffusion depth of the p-type impurity region 4 for junction isolation becomes deeper. As a result, for example, the n-type impurity layer 2
Even if the thickness is about 20 μm, it takes several tens of hours to form the p-type impurity region 4 reaching the p-type semiconductor substrate 1, resulting in a longer process.

The present invention has been made in view of the above points, and an object of the present invention is to provide a semiconductor device and a manufacturing method thereof capable of shortening the process time associated with element isolation. It is in.

[0005]

According to the first aspect of the present invention,
A support layer composed of a first conductivity type semiconductor substrate, a second conductivity type impurity layer formed on the first conductivity type semiconductor substrate, and the support layer reaching the first conductivity type semiconductor substrate. A first conductive type impurity layer formed by diffusing a first conductive type impurity into the groove, and the first conductive type impurity layer and the first conductive type semiconductor substrate. The second conductivity type semiconductor region separated by and is formed.

According to a second aspect of the present invention, a support layer made of a second conductivity type impurity layer is formed on the first conductivity type semiconductor substrate, an insulating film is formed on the support layer, and then the insulating film is formed. By removing the insulating film at a desired portion of the substrate, etching the insulating film as a mask until reaching the first conductivity type semiconductor substrate to form a groove, and diffusing the first conductivity type impurity into the groove. Forming a first conductivity type impurity layer,
A second conductivity type semiconductor region separated by a conductivity type impurity layer and the first conductivity type semiconductor substrate is formed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing a manufacturing process of a semiconductor device according to one embodiment of the present invention. First, an n-type impurity layer 2 which is a second conductivity type impurity layer is formed on a p-type semiconductor substrate 1 which is a first conductivity type semiconductor substrate, and an insulating film 3 such as a silicon oxide film is formed thereon ( FIG. 1 (a)).

Next, at a desired position of the insulating film 3, a part of the insulating film 3 is removed by using a photolithography technique and an etching technique to form an opening, and the insulating film 5 having the opening is formed. Anisotropic etching is performed using an alkaline etchant such as an aqueous potassium hydroxide (KOH) solution as a mask to form a groove 4 reaching the p-type semiconductor substrate 1 (FIG. 1B).

Subsequently, a p-type impurity such as boron (B) is ion-implanted and thermally diffused only in the groove 4 to form a p-type impurity region 5 which is a first conductivity type impurity layer, and the p-type semiconductor substrate 1 is formed. And the p-type impurity region 5 are connected to form an n-type semiconductor region 6 which is a second conductivity type semiconductor region separated from each other (FIG. 1C).

Therefore, in the present embodiment, the groove 4 is formed in the n-type impurity layer 2, and the p-type impurity is ion-implanted and thermally diffused only in the groove 4 to form the p-type impurity region 5. Even when the thickness of the n-type impurity layer 2 is increased, it is possible to form the p-type impurity layer 5 so as to be connected to the p-type semiconductor substrate 1 in a relatively short time, and it is possible to significantly reduce the process time. Become.

[0011]

The invention according to claim 1 or 2 is
A first conductive type semiconductor substrate, a support layer made of a second conductive type impurity layer formed on the first conductive type semiconductor substrate, and a support layer formed so as to reach the first conductive type semiconductor substrate. A first conductive type impurity layer formed by diffusing a first conductive type impurity into the groove;
Since the second conductivity type semiconductor region separated by the conductivity type impurity layer and the first conductivity type semiconductor substrate is formed, for example, even when the thickness of the support layer is increased, the second conductivity type semiconductor region is connected to the first conductivity type semiconductor substrate. As described above, it is possible to form the first conductivity type impurity layer in a relatively short time, and the process time can be significantly shortened as compared with the conventional one, and the semiconductor device capable of shortening the process time associated with element isolation can be provided. It was possible to provide the manufacturing method.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a manufacturing process of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a semiconductor device according to a conventional example.

[Explanation of symbols]

 1 p-type semiconductor substrate 2 n-type impurity layer 3 insulating film 4 groove 5 p-type impurity region 6 n-type semiconductor region

Claims (2)

[Claims] 1. A support layer composed of a first conductivity type semiconductor substrate, a second conductivity type impurity layer formed on the first conductivity type semiconductor substrate, and the first conductivity type semiconductor substrate on the support layer. And a first conductivity type impurity layer formed by diffusing the first conductivity type impurity into the groove part. The first conductivity type impurity layer and the first conductivity type impurity layer 1
A semiconductor device having a second conductivity type semiconductor region separated from a conductivity type semiconductor substrate. 2. A support layer made of a second conductivity type impurity layer is formed on a first conductivity type semiconductor substrate, an insulating film is formed on the support layer, and then a desired portion of the insulation film is insulated. The first conductive type impurity layer is formed by removing the film, performing etching using the insulating film as a mask until reaching the first conductive type semiconductor substrate to form a groove, and diffusing the first conductive type impurity into the groove. And a second conductivity type semiconductor region separated by the first conductivity type impurity layer and the first conductivity type semiconductor substrate are formed.