JPH04269821A - Manufacture of semiconductor device having structure body of semiconductor quantum thin wire - Google Patents

Abstract

PURPOSE:To highly accurately and precisely form a structure body of semiconductor quantum well thin wires by forming an oxide layer with a window on a semiconductor substrate, with the window being formed highly accurately and precisely, and then, the structure body of semiconductor quantum thin wires on the semiconductor substrate exposed on the bottom of the window by utilizing such a fact that, a semiconductor layer can be formed on a semiconductor substrate, but cannot be formed on an oxide layer by epitaxial growth. CONSTITUTION:An oxide layer 9 having a window 7 is formed on a semiconductor substrate 1 in such a way that, after a semiconductor layer 2 which is more easily oxidized than a semiconductor substrate 1 is thinly formed on the substrate 1, the window 7 is formed and the oxide layer 9 is formed by oxidizing the surface of the layer 2. After the layer 9 is formed, a semiconductor layer 2 is formed on the substrate 1 exposed on the bottom of the window 7 by epitaxial growth by utilizing such a fact that a semiconductor layer can be formed on a semiconductor substrate, but cannot be formed on an oxide layer by epitaxial growth. Thus a structure body of semiconductor quantum thin wire is formed on the substrate 1 exposed on the bottom of the window 7 opened in the oxide layer 9.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to methods for manufacturing various semiconductor devices having semiconductor quantum wire structures.

0002

2. Description of the Related Art Conventionally, a method for manufacturing a semiconductor device having a semiconductor quantum wire structure has been proposed, which will be described below with reference to FIGS. 11 and 12.

That is, a semiconductor substrate or a semiconductor layer (hereinafter referred to as semiconductor substrate 1 for simplicity) is prepared (FIG. 11A).
), an oxide layer 41 made of, for example, silicon dioxide is formed on the semiconductor substrate 1 by, for example, a plasma CVD method (FIG. 11B).

Next, a mask layer 4 made of, for example, a photoresist is formed on the oxide layer 41 (FIG. 11C), and has a window 5 with a pattern corresponding to a semiconductor quantum wire structure 10 to be described later.

Next, by etching the oxide layer 41 using the mask layer 4 as a mask, a pattern corresponding to the semiconductor quantum wire structure 10 described later is formed on the oxide layer 41.
12D).

Next, mask layer 4 is stripped off from above oxide layer 41 (FIG. 12E).

Next, when a semiconductor layer is generally grown and formed by an epitaxial growth method, if the conditions of the epitaxial growth method are appropriately selected, a semiconductor layer is formed on a semiconductor substrate, but a semiconductor layer is formed on an oxide layer. not formed,
Taking advantage of this fact, a semiconductor layer is formed by epitaxial growth on the region facing the window 42 of the oxide layer 41 of the semiconductor substrate 1, for example, in the form of layers 11, 12, and 1 as shown in the figure.
Various semiconductor quantum wire structures 10 are formed by forming semiconductor laminates in this order (FIG. 12F).

The above is a conventionally proposed method for manufacturing a semiconductor device having a semiconductor quantum wire structure.

[0009]

[Problems to be Solved by the Invention] In the conventional manufacturing method of a semiconductor device having a semiconductor quantum wire structure, in the step of forming the oxide layer 4 (FIG. 11A), the oxide layer 4 is formed thinly. Since it is difficult to do so, a window 44 having a pattern corresponding to the semiconductor quantum wire structure 10 that will be formed after exposing the semiconductor substrate 1 to the outside is formed in the oxide layer 4 with high precision and finely. Difficult to form.

For this reason, in the case of the above-described conventional method for manufacturing a semiconductor device having a semiconductor quantum wire structure, it is difficult to form the semiconductor quantum wire structure finely with high precision.
It had the following drawback.

[0011] Therefore, the present invention is free from the above-mentioned drawbacks.
This paper aims to propose a method for manufacturing a semiconductor device having a novel semiconductor quantum wire structure.

0012

[Means for Solving the Problems] A method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the first invention of the present application is as follows:
(i) forming a second semiconductor layer on the semiconductor substrate or the first semiconductor layer, which is more easily oxidized than the semiconductor substrate or the first semiconductor layer; (ii) forming the second semiconductor layer on the semiconductor substrate or the first semiconductor layer; (iii) forming a window in the second semiconductor layer that allows the semiconductor substrate or the first semiconductor layer to be exposed to the outside by etching the layer; and (iii) etching the second semiconductor layer by etching the second semiconductor layer. only, selectively,
a step of forming an oxide layer made of an oxide of the material of the second semiconductor layer, and (iv) a region of the semiconductor substrate or the first semiconductor layer facing the window of the second semiconductor layer by an epitaxial growth method; A semiconductor quantum wire structure having a step of selectively forming a semiconductor layer or a semiconductor stack forming the semiconductor quantum wire structure is provided only on the top.

[0013] Furthermore, the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the second invention of the present application includes (i) the first invention;
(ii) by oxidizing the semiconductor substrate, selectively forming an oxide layer made of an oxide of the material of the second semiconductor layer only on the surface of the second semiconductor layer of the semiconductor stack;
ii) selectively forming another semiconductor layer or semiconductor stack constituting the semiconductor quantum wire structure only on the end face of the second semiconductor layer of the semiconductor substrate by an epitaxial growth method.

[0014]

[Operations and Effects] According to the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the first invention of the present application, the method for manufacturing a semiconductor device having a conventional semiconductor quantum wire structure described above with reference to FIGS. 11 and 12 Similarly, when a semiconductor layer is generally formed by an epitaxial growth method, if the conditions of the epitaxial growth method are appropriately selected, the semiconductor layer will be formed on the semiconductor substrate, but it will not be formed on the oxide layer. Taking advantage of this fact, a semiconductor quantum wire structure is formed by epitaxial growth on the region of the semiconductor substrate or semiconductor layer facing the window of the oxide layer, but the oxide layer does not form the window. and, since the second semiconductor layer is literally a semiconductor layer, it can be formed thin and easily, so that it has a window. The window can be easily formed with high precision and finely, and therefore the window of the oxide layer can be formed with high precision and finely.

Therefore, according to the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the first invention of the present application, the semiconductor quantum wire structure can be manufactured by manufacturing a semiconductor device having a semiconductor quantum wire structure in the conventional method for manufacturing a semiconductor device having a semiconductor quantum wire structure. In contrast, it can be easily formed with high accuracy and fineness.

According to the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the second invention of the present application, the method for manufacturing a semiconductor device having a conventional semiconductor quantum wire structure described above with reference to FIGS. Generally, when a semiconductor layer is formed by an epitaxial growth method, if the conditions of the epitaxial growth method are appropriately selected, the semiconductor layer is formed on the semiconductor substrate, but not on the oxide layer. Taking advantage of this, a semiconductor quantum wire structure is formed on the end surface of the first semiconductor layer that is not covered with the oxide layer, but since the first and second semiconductor layers are literally semiconductor layers, , they can be easily formed with high precision and finely, and correspondingly, the oxide layer can be easily formed with high precision and finely.

Therefore, the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the second invention of the present application is similar to the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the first invention of the present application. , a semiconductor quantum wire structure can be easily formed with high accuracy and fineness compared to the method for manufacturing a semiconductor device having a conventional semiconductor quantum wire structure described above with reference to FIGS. 11 and 12.

[0018]

[Example 1] Next, a first method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention will be explained with reference to FIGS. 1 to 4.
Let's describe an example.

In FIGS. 1 to 4, parts corresponding to those in FIGS. 11 and 12 are designated by the same reference numerals, and detailed description thereof will be omitted.

A method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention shown in FIGS. 1 to 4 includes the following sequential steps to manufacture a semiconductor device having a semiconductor quantum wire structure.

That is, a semiconductor substrate 1 made of, for example, InP is prepared (FIG. 1A), similar to that described above in the case of the manufacturing method of a semiconductor device having a conventional semiconductor quantum wire structure described above with reference to FIGS. 11 and 12, and , on the semiconductor substrate 1, a semiconductor layer 2 made of, for example, InAlAs, which is more easily oxidized than the semiconductor substrate 1, and a semiconductor layer 2, made of, for example, InAlAs, which is not easily oxidized.
A semiconductor layer 3 as a cap layer is formed by stacking them in this order (FIG. 1B).

11 and 12 on the semiconductor layer 3.
In the case of the conventional method for manufacturing a semiconductor device having a semiconductor quantum wire structure described above, a mask layer 4 having windows 5 similar to those described above is formed (FIG. 1C).

Next, by etching the semiconductor layer 3 using the mask layer 4 as a mask, a window 6 with a pattern corresponding to a semiconductor quantum wire structure 10 to be described later is formed in the semiconductor layer 3 (FIG. 2D). .

Next, the mask layer 4 is peeled off from above the semiconductor layer 3 (FIG. 2E). Next, by etching the semiconductor layer 2 using the semiconductor layer 3 as a mask, a window 7 having a pattern corresponding to a semiconductor quantum wire structure 10 to be described later is formed in the semiconductor layer 2 (FIG. 2F).

Next, the semiconductor layer 3 is removed by dissolution from above the semiconductor layer 2 (FIG. 3G). In this case, if the semiconductor layer 3 is made of the same material as the semiconductor substrate 1 as in this example, the surface side of the region of the semiconductor layer 2 of the semiconductor substrate 1 facing the window 7 will also partially It is dissolved away and becomes a new surface 8.

Next, by utilizing the fact that the semiconductor layer 2 is more easily oxidized than the semiconductor substrate 1, the material of the semiconductor layer 2 is selectively removed only on the surface of the semiconductor layer 2 by oxidation treatment. An oxide layer 9 made of oxide is formed (FIG. 3H). In this case, although not shown, the oxide layer 9 is similar to the semiconductor layer 2.
It also extends on the inner surface of the window 7 to a thickness similar to or thinner than that on the semiconductor layer 2, but in any case, the semiconductor layer 2
This means that the window 9' corresponds to the window 7 of .

Next, when a semiconductor layer is generally formed by an epitaxial growth method, if the conditions of the epitaxial growth method are appropriately selected, the semiconductor layer is formed on the semiconductor substrate, but not on the oxide layer. Taking advantage of this fact, the window 9' of the oxide layer 9 of the semiconductor substrate 1 and the window 7 of the semiconductor layer 2 are formed by epitaxial growth.
As in the case of the manufacturing method of the conventional semiconductor device having the semiconductor quantum wire structure described above with reference to FIG. 11 and FIG.
and 13 to form a semiconductor stack in that order, thereby forming the semiconductor quantum wire structure 10 (FIG. 3I).

Next, if necessary, oxide layer 9 is removed from above semiconductor layer 2 (FIG. 4J). Next, if necessary, a semiconductor layer 2 and a semiconductor quantum wire structure 1 are placed on the semiconductor substrate 1.
A semiconductor layer 14 made of, for example, InP is buried so as to bury 0.
(Fig. 4K).

The above is the first embodiment of the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention.

According to the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention shown in FIGS. 1 to 4, FIG.
Similarly to the method for manufacturing a semiconductor device having a conventional semiconductor quantum wire structure described above with reference to FIG. By utilizing the fact that the semiconductor layer is formed on the semiconductor substrate but not on the oxide layer, the semiconductor substrate 1
A semiconductor quantum wire structure 10 is formed by epitaxial growth on the region 8 facing the window 9' of the oxide layer 9 of the semiconductor layer 2 forming the window 7.
Since the semiconductor layer 2 is literally a semiconductor layer, it can be formed thin and easily, and therefore the windows 7 can be formed in it with high accuracy and fineness. It can be easily formed, and therefore, the windows 9' of the oxide layer 9 can be formed finely with high precision.

Therefore, according to the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention shown in FIGS. High precision and fineness compared to
Can be easily formed.

[0032]

[Embodiment 2] Next, a second embodiment of a semiconductor device having a semiconductor quantum wire structure according to the present invention will be described with reference to FIGS. 5 and 6.

A second embodiment of the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention shown in FIGS. Manufacture the device.

That is, a semiconductor in which, on a semiconductor substrate 1 made of, for example, InP, semiconductor layers 23 made of, for example, InP and semiconductor layers 24 made of, for example, InAlAs series, which are more easily oxidized, are sequentially and alternately laminated. A base body 20 having a semiconductor base body 22 made of a laminate is prepared (FIG. 5A
).

Next, by oxidizing one end surface side of the semiconductor body 22, the semiconductor layer 23 of the semiconductor body 22 is oxidized.
An oxide layer 25 made of an oxide of the material of the semiconductor layer 23 is selectively formed only on the end face of the semiconductor layer 23 (FIG. 5B). In this case, if the semiconductor layer 23 is made of the same material as the semiconductor substrate 21 as in this example, an oxide layer 25' is also formed on one end surface of the semiconductor substrate 1, and the uppermost layer of the semiconductor substrate 22 is When the semiconductor layer 23 is formed, an oxide layer 25 is also formed on the semiconductor layer 23, although not shown.

Next, when a semiconductor layer is grown and formed by an epitaxial growth method, if the conditions of the epitaxial growth method are appropriately selected, the semiconductor layer is formed on the semiconductor substrate, but not on the oxide layer. Taking advantage of this fact, the epitaxial growth method is used to selectively grow only the semiconductor layer 24 of the semiconductor substrate 22 in FIGS.
A semiconductor quantum wire structure 10 similar to that described above in FIG. 4 is similarly formed (FIG. 6C).

Next, the oxide layer 25 and the semiconductor quantum wire structure 10 are placed on the end face of the semiconductor substrate 22 on the side on which the semiconductor quantum wire structure 10 is formed.
A semiconductor layer 30 made of, for example, InP is formed so as to be buried together with the semiconductor layer 5' (FIG. 6).

The above is the second embodiment of the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention.

According to the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention, similar to the method for manufacturing a semiconductor device having a conventional semiconductor quantum wire structure described above with reference to FIGS. Generally, when forming a semiconductor layer by epitaxial growth, if the conditions of the epitaxial growth method are appropriately selected, the semiconductor layer will be formed on the semiconductor substrate, but not on the oxide layer. Taking advantage of this fact, the semiconductor quantum wire structure 10 is formed on the end surface of the semiconductor layer 24 that is not covered with the oxide layer 25. However, since the semiconductor layers 23 and 24 are literally semiconductor layers, they are It is possible to easily form the oxide layer 25 with high precision and fineness, and accordingly, the oxide layer 25 can be easily formed with high precision and fineness.

Therefore, in the case of the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention shown in FIGS. 5 and 6, the semiconductor device having a semiconductor quantum wire structure according to the present invention described above with reference to FIGS. As in the case of the manufacturing method, the semiconductor quantum wire structure 10 can be easily manufactured with high accuracy and fineness compared to the method of manufacturing a semiconductor device having a conventional semiconductor quantum wire structure described above with reference to FIGS. 11 and 12. can be formed into

[0041]

[Embodiment 3] Next, a third embodiment of a semiconductor device having a semiconductor quantum wire structure according to the present invention will be described with reference to FIGS. 7 to 10. In FIGS. 7 to 10, FIGS. 5 and 6
The same reference numerals are given to the corresponding parts, and detailed explanation will be omitted.

In the embodiment of the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention shown in FIGS. 7 to 10, a semiconductor device having a semiconductor quantum wire structure is manufactured by taking the following sequential steps. do.

That is, as in the case of the semiconductor device having the semiconductor quantum wire structure according to the present invention described above with reference to FIGS. 5 and 6, a base body 20 having a semiconductor base body 22 made of a similar semiconductor stack is prepared ( 7A). Next, a mask layer 31 is formed on the semiconductor substrate 22 (FIG. 7B). next,
By etching the semiconductor substrate 22, the tape is removed.
A perforated end surface is formed (FIG. 8C). Next, mask layer 31 is removed (FIG. 8D).

Next, as in the case of the semiconductor device having the semiconductor quantum wire structure according to the present invention described above with reference to FIGS. An oxide layer 25 made of an oxide of the material of the semiconductor layer 23 is selectively formed only on the end face of the semiconductor layer 23 (FIG. 9E).

Next, similar to the case of FIGS. 5 and 6, semiconductor quantum molecules similar to those described above in FIGS. 1 to 4 are selectively grown only on the semiconductor layer 24 of the semiconductor stack 22 by epitaxial growth. A thin wire structure 10 is similarly formed (FIG. 9
F).

Next, the oxide layer 25 and the semiconductor quantum wire structure 10 are buried together with the oxide layer 25' of the semiconductor substrate 21 on the end surface of the semiconductor stack 22 on the side where the semiconductor quantum wire structure 10 is formed. In this manner, a semiconductor layer 30 made of, for example, InP is formed (FIG. 10G).

The above is the second embodiment of the method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention.

According to the method of manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention, although detailed explanation will be omitted, it is clear that the same effects as those shown in FIGS. 5 and 6 can be obtained. Probably.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing sequential steps for explaining a first embodiment of a method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention.

FIG. 2 is a schematic cross-sectional view showing sequential steps for explaining a first embodiment of a method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention.

FIG. 3 is a schematic cross-sectional view showing sequential steps for explaining a first embodiment of a method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention.

FIGS. 4A and 4B are schematic cross-sectional views showing sequential steps for explaining a first embodiment of a method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention; FIGS.

FIG. 5 is a schematic cross-sectional view showing sequential steps for explaining a second embodiment of a method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention.

FIG. 6 is a schematic cross-sectional view showing sequential steps for explaining a second embodiment of a method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention.

FIGS. 7A and 7B are schematic cross-sectional views showing sequential steps for explaining a third embodiment of a method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention; FIGS.

FIG. 8 is a schematic cross-sectional view showing sequential steps for explaining a third embodiment of a method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention.

FIGS. 9A and 9B are schematic cross-sectional views showing sequential steps for explaining a third embodiment of a method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention; FIGS.

FIGS. 10A and 10B are schematic cross-sectional views showing sequential steps for explaining a third embodiment of a method for manufacturing a semiconductor device having a semiconductor quantum wire structure according to the present invention; FIGS.

FIGS. 11A and 11B are schematic cross-sectional views showing sequential steps for explaining a method for manufacturing a semiconductor device having a conventional semiconductor quantum wire structure.

FIGS. 12A and 12B are schematic cross-sectional views showing sequential steps for explaining a method for manufacturing a semiconductor device having a conventional semiconductor quantum wire structure.

[Explanation of symbols]

1 Semiconductor substrate 2
semiconductor layer 3
Semiconductor layer 4 as a cap layer
Mask layers 6, 7 Window 9 Oxide layer 9'
Window 10 Semiconductor quantum wire structures 11, 12, 13 Semiconductor layer

Claims (2)

[Claims] 1. A step of forming, on a semiconductor substrate or a first semiconductor layer, a second semiconductor layer that is more easily oxidized than the semiconductor substrate or the first semiconductor layer; A step of forming a window in the second semiconductor layer that exposes the semiconductor substrate or the first semiconductor layer to the outside by an etching treatment, and a step of forming a window selectively only on the surface of the second semiconductor layer by an oxidation treatment. Basically, the second
A step of forming an oxide layer made of an oxide of the material of the semiconductor layer, and an epitaxial growth method, selectively forming an oxide layer only on a region of the semiconductor substrate or the first semiconductor layer facing the window of the second semiconductor layer. Specifically, a method for manufacturing a semiconductor device having a semiconductor quantum wire structure, which includes a step of forming a semiconductor layer or a semiconductor stack forming the semiconductor quantum wire structure. 2. A step of preparing a semiconductor substrate made of a semiconductor laminate in which a first semiconductor layer and a second semiconductor layer that is more easily oxidized than the first semiconductor layer are sequentially and alternately stacked; By oxidation treatment, the second semiconductor layer is selectively applied only to the surface of the second semiconductor layer of the semiconductor substrate.
selectively configuring a semiconductor quantum wire structure only on the end surface of the first semiconductor layer of the semiconductor substrate by forming an oxide layer made of an oxide of the material of the semiconductor layer and by an epitaxial growth method. 1. A method for manufacturing a semiconductor device having a semiconductor quantum wire structure, comprising the step of forming another semiconductor layer or a semiconductor stack.