KR19990016619A - Manufacturing method of electroluminescent device using porous silicon - Google Patents

Abstract

(A) forming polysilicon on the upper surface of the substrate; (B) forming porous silicon by anodizing the polysilicon in a hydrofluoric acid solution of a predetermined concentration; (c) forming an ITO electrode pattern on the porous silicon by a photoresist method; (d) the ITO film is Forming an insulating film on the removed portion; And (e) removing the pattern; relates to a method for manufacturing an electroluminescent device using a porous silicon comprising a, forming an insulating film on the porous silicon to prevent the current flow to the portion other than the ITO film to improve the light efficiency You can increase it.

Description

Manufacturing method of electroluminescent device using porous silicon

The present invention relates to a method of manufacturing an electroluminescence device (EL) using porous silicon.

The display device includes a plasma display panel (PDP) using gas discharge between a charged electrode, a cathode ray tube (CRT) using light emission of a phosphor by scanning an electron beam, and an anode of hot electrons. There are various kinds of things, such as a fluorescent fluorescent display (VFD) that emits light by colliding with a phosphor coated on it, and an electroluminescent device (EL) using an emission effect by an electric field.

Each display device is selectively applied according to the purpose of use according to its function and structural characteristics. These display devices are structurally and functionally improved in many fields in that they visualize electrical image signals or data signals.

The recent development trend of display apparatuses is to manufacture a display apparatus having a large screen with high definition and a thin film to apply to a demand for a medium displaying a large amount of public information and high definition television (HDTV).

In accordance with this development trend, researches on light emitting devices using porous silicon have been actively conducted.

A light emitting device using porous silicon emits light in the visible region according to the characteristics of the porous silicon layer when a predetermined voltage is applied to the porous silicon substrate or irradiated with light. The porous silicon is manufactured by electrochemically anodizing in a state in which silicon is immersed in an electrolyte solution. At this time, the characteristics of the porous silicon obtained vary depending on the concentration of the electrolyte solution used, the time to be immersed in the electrolyte solution, the current density to be applied, and the like to emit light of different wavelength ranges, that is, red, green, and blue.

Most light emitting devices using porous silicon having such operating characteristics may be made of porous silicon using a silicon wafer, or by making a porous region in a silicon layer using a glass substrate.

By the way, the electroluminescent device using the porous silicon is a field to be continuously researched and developed because the technical accumulation that can sufficiently exhibit the light emitting effect is still insufficient.

The present invention was devised to achieve the above object, and an object thereof is to provide a method of manufacturing an electroluminescent device using porous silicon having an improved structure to increase light efficiency by forming an insulating film on porous silicon.

1 is a vertical cross-sectional view showing a light emitting device using a porous silicon completed by the manufacturing method according to the present invention,

2 to 7 is a vertical cross-sectional view after each step of the manufacturing step of the electroluminescent device using the porous silicon according to the present invention,

2 is a vertical sectional view showing a state after polysilicon is formed on a substrate of a silicon element,

3 is a vertical cross-sectional view showing a state after the porous silicon is formed on the substrate of FIG.

4 is a vertical cross-sectional view showing a state after the ITO film is formed on the porous silicon of FIG.

5 is a vertical cross-sectional view showing a state after the photoresist is applied on the ITO film of FIG.

6 is a vertical cross-sectional view showing a state after etching the ITO film of FIG.

FIG. 7 is a vertical cross-sectional view illustrating a state after an insulating film is formed on the porous silicon of FIG. 6.

* Brief description of symbols for the main parts of the drawings

11.p-type silicon

12. Polysilicon Layer

13. Porous Silicon Layer

14. ITO membrane

15. Photoresist

16. Silicon oxide film

In order to achieve the above object, a method of manufacturing an electroluminescent device using the porous silicon of the present invention comprises the steps of: (a) forming polysilicon on the upper surface of the substrate; (B) forming porous silicon by anodizing the polysilicon in a hydrofluoric acid solution of a predetermined concentration; (c) forming an ITO electrode pattern on the porous silicon by a photoresist method; (d) the ITO film is Forming an insulating film on the removed portion; And (e) removing the pattern.

The present invention is characterized in that in step (b) the hydrofluoric acid solution has a concentration of 10 to 20% by weight, and the current density during the polarization process is 1 to 5 mA / cm 2.

According to the present invention, the insulating film is preferably a silicon oxide film.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of an electroluminescent device using a porous silicon and a method for manufacturing the same according to the present invention.

1 illustrates an example of an electroluminescent device using porous silicon according to the present invention.

Referring to the drawings, a porous silicon layer 13 is formed on a substrate 11 made of silicon. An ITO film 14 having a predetermined pattern is formed on the porous silicon layer 13, and silicon oxide films SIO ₂ and 16 are formed between the ITO films 14 as insulating films.

The method for manufacturing the electroluminescent device using the porosity is as shown in Figs.

Referring to FIG. 2, an n-type doped polysilicon layer 12 is formed of a thin film on an upper surface of a p-type silicon substrate 11 having a predetermined thickness. In this case, the polysilicon layer 12 is preferably formed on the p-type silicon substrate 11 by applying a predetermined power by low pressure chemical vapor deposition (LPCVD) method.

3, the polysilicon layer 12 is anodized to make the silicon structure porous. That is, the polysilicon layer 12 is impregnated in the hydrofluoric acid solution, and a predetermined current is applied to change the texture. An electrochemical treatment method for changing the structure of the polysilicon layer 12 into the porous silicon layer 13 may be anodization method. The process variables of the anodization method include electrolyte concentration, current density, and time. And pH. At this time, the electrolytic conditions of the anodization is a concentration of hydrofluoric acid is about 10 to 20% by weight, and a current density of about 1 to 5 mA / ㎠.

4 shows that an ITO film 14 is formed on the porous silicon layer 13. A conventional method for forming the ITO film 14 uses sputtering.

Subsequently, as shown in FIG. 5, a photoresist 15 is coated on the upper surface of the ITO film 14 by a photolithography process to form a predetermined pattern.

When a predetermined pattern is formed on the ITO film 14, as shown in FIG. 6, the ITO film 14 is etched using an etching solution to remove the ITO film 14 other than the portion where the pattern is formed. At this time, as the etching solution, the ratio of distilled water to hydrochloric acid to nitric acid is preferably 12.5: 12.5: 1.

Subsequently, as shown in FIG. 7, the portion from which the ITO film 14 has been removed forms a silicon oxide film (SiO ₂ , 16) that can act as an insulating film since the porous silicon 13 is directly exposed to the outside. This is because the light emission phenomenon occurs minutely in addition to the portion where the ITO film 14 is formed. At this time, there may be a variety of methods for forming the silica film 16, but is usually formed by applying a predetermined power source by using a platinum electrode as a catalyst by immersion in the electrolyte solution.

As such, when the photoresist formed on the ITO film 14 is peeled off, an electroluminescent device using porous silicon is completed as shown in FIG. 1.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the method of manufacturing the electroluminescent device using the porous silicon of the present invention can increase the light efficiency by forming an insulating film on the porous silicon to prevent current from flowing to portions other than the ITO film.

Claims (3)

(A) forming polysilicon on the upper surface of the substrate; (B) forming porous silicon by anodizing the polysilicon in a hydrofluoric acid solution of a predetermined concentration; (C) forming an ITO electrode pattern on the porous silicon by a photoresist method; (D) forming an insulating film in a portion where the ITO film is removed; And (E) removing the pattern; manufacturing method of the electroluminescent device using a porous silicon comprising a. The method of claim 1, In step (b), the hydrofluoric acid solution has a concentration of 10 to 20% by weight, and a current density during the anodization process is 1 to 5 mA / cm 2. The method of claim 1, The insulating film is a method of manufacturing an electroluminescent device using porous silicon, characterized in that the silicon oxide film.