JPS6240871B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for inactivating pinholes in constituent layers of solar cells and the like.

Generally, when manufacturing solar cells, capacitors, etc., the former uses a semiconductor and the latter uses a sandwich structure in which a dielectric is sandwiched between electrodes. In this case, if a pinhole exists in a semiconductor or dielectric layer, a short circuit will occur through the pinhole, so these devices and components will not work. Since pinholes are easily generated in semiconductor films and dielectric films, deterioration of device functionality due to the short circuit effect of voltage through these pinholes is a serious problem.

Traditionally, to eliminate the short circuit effect caused by pinholes,
Methods used in solar cells include forming a thick semiconductor film, and in capacitors, applying high voltage to the electrodes to melt and blow away the electrodes in the pinhole area. .

However, forming an unnecessarily thick semiconductor film is a waste of materials and manufacturing time, and removing the pinhole effect by applying high voltage to a capacitor using metal foil may cause thermal damage to the semiconductor film. There were problems such as gender.

In order to solve the above-mentioned problems, the present invention takes advantage of the fact that photoresist is an electrical insulator, that is, actively employs photolithography technology to eliminate pinholes using photoresist. The objective is to provide a method for improving the performance and manufacturing yield of devices and components by filling and eliminating pinhole shorting effects. EMBODIMENT OF THE INVENTION Hereinafter, embodiments of the present invention will be explained based on the drawings for manufacturing a solar cell.

FIG. 1 is a diagram for explaining the steps of a method for inactivating pinholes in the constituent layers of a solar cell.

As shown in FIG. 1a, a NESA film or a thin metal film 2 is deposited on a glass substrate 1. The Nesa film 2 is made of In ₂ O ₃ which has optical transparency and conductivity.
Use SnO ₂ etc. Further, the metal film 2 is made of gold (Au),
Silver (Ag), aluminum (Al), etc. are used, but the film thickness is made as thin as about 100 Å to make it translucent to light. Further, a semiconductor 3 is formed on the NESA film or the metal film 2. FIG. 1a shows the state of pinholes 4 in this semiconductor layer 3.

Next, a photoresist 5 is applied onto the semiconductor layer 3 in which the pinhole 4 is located, and the pinhole 4 is filled with the photoresist, as shown in FIG. 1b. Exposure is applied through the Nesa film or thin metal film 2 in the direction of the arrow shown. Expose and develop,
When rinsing and photoresist baking are performed, the resist portions exposed to light remain, and the resist portions not exposed to light are removed, resulting in the state shown in FIG. 1c. That is,
The photoresist 5 in FIG.
At the same time that the photoresist 5 is filled, the photoresist also remains above the pinhole 4 and is cured. The photoresist in other portions is removed to expose the surface of the semiconductor layer 3. When a conductive (metallic) film 6 is formed on the semiconductor layer 3 and the photoresist 5, the state shown in FIG. By providing a lead electrode 8 on top, the solar cell shown in FIG. 1e is constructed. The solar cell is completed by coating an antireflection film (not shown) on the surface of the glass substrate 1 on the side exposed to sunlight.

The photoresist used in this example is an n-type resist, that is, a type that polymerizes when irradiated with light.

In the solar cell shown in FIG. 1, when the NESA film 2 is, for example, an n-type semiconductor In ₂ O ₃ , the semiconductor layer 3 is a P type, and the forbidden band width of the NESA film 2 is the same as the forbidden band of the semiconductor layer 3. By making it larger than the width, a highly efficient heterojunction solar cell utilizing the window effect can be obtained. In the case of a very thin metal film 2, for example a gold (Au) film, the semiconductor layer 3 may be either n-type or p-type, and in this way a Schottky barrier solar cell is obtained. If the opposite side of the semiconductor film coated with photoresist, ie, the substrate 1, 2, etc. in the figure, is opaque to light, X-ray irradiation is performed instead of light.

It goes without saying that the same method as in the case of the constituent layers of a solar cell can also be applied to pinholes in the dielectric of a capacitor.

As explained in detail above, the present invention eliminates short-circuit effects through pinholes by filling pinholes in semiconductor layers, etc., which are constituent layers of solar cells, etc., using photoresist exposure and its curing technology. The aim is to improve device functionality and manufacturing yield.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of an embodiment in which the present invention is applied to a solar cell. Figure 1a shows a state in which a pinhole exists in a semiconductor layer, and Figure 1b shows a photoresist on a semiconductor layer. Figure 1c is a diagram of the photoresist being coated and exposed, Figure 1c is a diagram of the photoresist after exposure, development, rinsing and baking, and Figure 1d is a conductive film on the photoresist filled in the semiconductor and pinholes. The formed figure, FIG. 1e, shows a completed solar cell by attaching lead electrodes to the Nesa film or thin metal film and the ohmic electrode film, respectively. In the figure, 1 is a glass substrate, 2 is a NESA film or a thin metal film, 3 is a semiconductor, 4 is a pinhole, 5 is a photoresist, 6 is an ohmic electrode film, and 7 and 8 are lead electrodes.

Claims (1)

[Claims] 1. A step of applying a photoresist on a semiconductor film, etc. having a pinhole, filling the pinhole with the photoresist, and covering the semiconductor film with the photoresist, and a step of applying the photoresist to the semiconductor film, etc. The pinhole is closed with a hardened photoresist by irradiating light or X-rays from the opposite side of the pinhole, exposing the photoresist filled in the pinhole, developing, rinsing, and baking. A method for inactivating pinholes in constituent layers of solar cells, etc.