JPH06151912A - Optical semiconductor device and its manufacture - Google Patents

Abstract

PURPOSE:To shorten the manufacturing time by simplifying the process thereby saving manufacturing facility, concerning an optical semiconductor device and its manufacture. CONSTITUTION:This optical semiconductor device has a one-conductivity-type semiconductor layer 3, an intrinsic semiconductor layer 3, an opposite-conductivity-type semiconductor layer 5, and a transparent conductive film 7 stacked in order on a substrate, and a chromium electrode 9 arranged on the transparent conductive film 7, and the transparent conductive film 7 contains phosphorus and chromium. Moreover, this includes a process of stacking the one-conductivity-type semiconductor layer 3, the intrinsic semiconductor layer 4, and the opposite-conductivity-type semiconductor layer 5 in order on the substrate 1, a process of accumulating a chromium film 8, after sticking phosphorus to the surface of the opposite- conductivity-type semiconductor layer 5, and further, forming the transparent conductive film 7 including phosphorus and chromium between the opposite-conductivity-type semiconductor layer 5 and the chromium film 8 by heat treatment, and a process of selectively etching the chromium film 8, using a mask, thereby forming a window 10 to expose the transparent conductive film 7. Moreover, the stacking of the one-conductivity-type semiconductor layer 3, the intrinsic semiconductor layer 4, and the opposite-conductivity-type semiconductor layer 5 and the sticking of phosphorus to the surface of the opposite-conductivity-type semiconductor layer 5 are performed in the continuous process by plasma CVD method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor device and its manufacturing method, and more particularly to a solar cell and its manufacturing method. In recent years, solar cells have been required to have high efficiency and low cost.

[0002]

2. Description of the Related Art FIGS. 2A to 2C are sectional views in order of steps showing a conventional example. The conventional manufacturing process will be described below with reference to these drawings.

Referring to FIG. 2 (a), a substrate 1 is, for example, a glass substrate, on which a thickness of
Deposit 800Å Cr film 2. The Cr film 2 becomes the lower electrode. On top of that, a thickness of 100
A Å n-type semiconductor layer 3, a 5000 Å-thick intrinsic semiconductor layer 4, and a 100 Å-thick p-type semiconductor layer 5 are continuously formed.

See FIG. 2 (b). For example, an ITO film 11 having a thickness of 1000 Å to be a transparent conductive film is formed by a sputtering method, and then a Cr film 8 to be an opaque electrode film for reducing resistance is formed by a sputtering method. Form.

Referring to FIG. 2 (c), the Cr film 8 is etched using a mask to form Cr in a lattice pattern.
At the same time as forming the Cr electrode 9 while leaving the film 8, the ITO film 11 is formed.
A window 10 is formed to expose the. The Cr electrode 9 is an upper electrode. In this way, the solar cell is completed.

[0006]

In the above-described conventional example, it is general that the formation of the ITO film 11 serving as the transparent conductive film and the formation of the Cr film 8 serving as the opaque electrode film are separately performed by different sputtering devices. Therefore, the cost of the manufacturing equipment is increased and the manufacturing time becomes long.

In view of the above problems, the present invention provides a method for saving the cost of manufacturing equipment and shortening the manufacturing time.

[0008]

1 (a) to 1 (c) are sectional views in order of the steps, showing an embodiment of the present invention. The above-mentioned problem is solved by one conductive type semiconductor layer 3, an intrinsic semiconductor layer 4, an opposite conductive type semiconductor layer 5, a transparent conductive film 7, and a chromium electrode 9 arranged on the transparent conductive film 7, which are sequentially stacked on the substrate 1. And the transparent conductive film 7 is solved by an optical semiconductor device containing phosphorus and chromium.

Further, a step of sequentially laminating the one conductivity type semiconductor layer 3, the intrinsic semiconductor layer 4, and the opposite conductivity type semiconductor layer 5 on the substrate 1, and a chromium film after phosphorus is attached to the surface of the opposite conductivity type semiconductor layer 5. 8 and deposit a transparent conductive film 7 containing phosphorus and chromium between the opposite conductivity type semiconductor layer 5 and the chromium film 8 by heat treatment, and selectively etch the chromium film 8 using a mask. And the window 10 exposing the transparent conductive film 7
And a method of manufacturing an optical semiconductor device, the method including:

In addition, the lamination of the one conductivity type semiconductor layer 3, the intrinsic semiconductor layer 4, and the opposite conductivity type semiconductor layer 5 and the deposition of phosphorus on the surface of the opposite conductivity type semiconductor layer 5 are performed by plasma CVD.
This is solved by the above-described method for manufacturing an optical semiconductor device, which is performed in successive steps.

[0011]

In the present invention, the device used for laminating the one conductivity type semiconductor layer 3, the intrinsic semiconductor layer 4, and the opposite conductivity type semiconductor layer 5 for forming the phosphorus (P) layer which becomes the transparent conductive film can be used as it is. The apparatus used for forming the ITO film in the conventional example, for example, the sputtering apparatus is not required.

Further, since the P layer to be the transparent conductive film can be formed continuously after the lamination of the one conductivity type semiconductor layer 3, the intrinsic semiconductor layer 4 and the opposite conductivity type semiconductor layer 5,
The manufacturing time can be shortened as compared with the conventional example.

Further, by selectively etching the chromium film 8, the transparent conductive film 7 containing phosphorus and chromium can be left without being etched.

[0014]

1 (a) to 1 (c) are sectional views in order of steps showing an embodiment, in which 1 is a glass substrate, 2 is a Cr film and a lower electrode, 3 is an n-type a-Si layer, 4 Is an intrinsic a-Si layer, 5 is p
Type a-Si layer, 6 is a P (phosphorus) layer, 7 is a transparent conductive film, 8
Is a Cr film, 9 is a Cr electrode and is an upper electrode, and 10 is a window. Examples will be described below with reference to these drawings.

Referring to FIG. 1 (a), the substrate 1 is, for example, a glass substrate, on which, for example, a thickness is set.
A 800 Å Cr film 2 is deposited by sputtering. The Cr film 2 becomes the lower electrode. Further, for example, by plasma CVD, an n-type semiconductor layer with a thickness of 100Å 3, an intrinsic semiconductor layer with a thickness of 5000Å 4, a p-type semiconductor layer with a thickness of 100Å 5, a thickness of 100
Å The following P layer 6 is continuously formed. The n-type semiconductor layer 3 is, for example, a P-doped amorphous silicon (a-Si) layer, the intrinsic semiconductor layer 4 is, for example, a non-doped a-Si layer, and the p-type semiconductor layer 5 is, for example, B (boron) -doped. It is an a-Si layer. For the P layer 6, PH ₃ gas is introduced into the chamber where the n-type semiconductor layer 3 is deposited or another chamber is ignited to generate plasma, and the glass substrate 1 is exposed to the plasma to expose P to the surface of the p-type semiconductor layer 5. It is formed by attaching to. The adhesion thickness is, for example, 50Å, and the conditions therefor are, for example, PH.
The pressure of the _three gases is 1 Torr, the flow rate is 200 sccm, the power is 200 W, and the film formation time is 10 minutes.

Next, as shown in FIG. 1B, a Cr film 8 having a thickness of 2000 Å, which will be an opaque electrode film, is formed by, for example, a sputtering method. By heating at about 200 ° C, the P layer 6 has Cr and Si existing above and below.
And the transparent conductive film 7 is formed.

Referring to FIG. 1C, a photoresist is applied on the entire surface, and a grid-shaped resist pattern is formed by exposure and development. Using this resist pattern as a mask, the Cr film 8 is selectively etched with an aqueous solution containing cerium nitrate second ammonium as a main component to form a Cr electrode 9 while leaving the Cr film 8 in a grid pattern. At the same time, a window 10 exposing the transparent conductive film 7 is formed. The Cr electrode 9 is an upper electrode. In this way, the solar cell is completed.

Although a glass substrate is used as the substrate 1 in the above embodiment, a Si substrate can also be used. The point is that it may be an insulating substrate or a semiconductor substrate. Further, in the above embodiment, the n-type semiconductor layer, the i-type semiconductor layer, and the p-type semiconductor layer are stacked in this order, but the p-type semiconductor layer, the i-type semiconductor layer, and the n-type semiconductor layer are stacked.
The type semiconductor layers may be stacked in this order.

[0019]

As described above, according to the present invention,
By forming the transparent conductive film containing Cr and P in place of the conventional transparent conductive film made of the ITO film, the manufacturing equipment used for forming the ITO film becomes unnecessary. In addition, the manufacturing time can be shortened.

The present invention contributes to cost reduction of solar cells.

[Brief description of drawings]

1A to 1C are sectional views in order of the processes, showing an embodiment.

2A to 2C are cross-sectional views in order of the processes, showing a conventional example.

[Explanation of symbols]

 1 is a substrate, glass substrate 2 is a Cr film, lower electrode 3 is an n-type semiconductor layer, n-type a-Si layer 4 is an intrinsic semiconductor layer, and i-type a-Si layer 5 is a p-type The semiconductor layer is a p-type a-Si layer 6, the P layer 7 is a transparent conductive film, and the transparent conductive film containing Cr and P is 8. The Cr film 9 is the Cr electrode, and the upper electrode 10 is the window 11 is ITO. film

Claims (3)

[Claims] 1. A one-conductivity-type semiconductor layer (3), an intrinsic semiconductor layer (4), and an opposite-conductivity-type semiconductor layer, which are sequentially stacked on a substrate (1).
(5) having a transparent conductive film (7) and a chromium electrode (9) disposed on the transparent conductive film (7), wherein the transparent conductive film (7) contains phosphorus and chromium. Optical semiconductor device. 2. A step of sequentially laminating a one conductivity type semiconductor layer (3), an intrinsic semiconductor layer (4) and an opposite conductivity type semiconductor layer (5) on a substrate (1), and the opposite conductivity type semiconductor layer (5). ) After depositing phosphorus on the surface, a chromium film (8) is deposited, and a heat treatment is performed to form a transparent conductive film (7) containing phosphorus and chromium between the opposite conductivity type semiconductor layer (5) and the chromium film (8). The step of forming and the transparent conductive film by selectively etching the chromium film (8) using a mask
And (7) a step of forming a window (10) exposing the optical semiconductor device. 3. A stack of the one conductivity type semiconductor layer (3), the intrinsic semiconductor layer (4), and the opposite conductivity type semiconductor layer (5) and deposition of phosphorus on the surface of the opposite conductivity type semiconductor layer (5). Is plasma C
3. The continuous process according to the VD method is performed.
A method for manufacturing the optical semiconductor device described.