Patterning Method for Carbon-Based Substrate

Abstract

A patterning method for a carbon-based substrate is provided. The patterning method for the carbon-based substrate includes the following steps. The carbon-based substrate is provided. An atmospheric pressure plasma is produced from a plasma gas under an open air environment. The plasma gas includes oxygen. The carbon-based substrate is etched by the atmospheric pressure plasma.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates in general to a patterning method for a substrate, and more particularly to a patterning method for a carbon-based substrate.

2. Description of the Related Art

The carbon-based substrate, having the features of high conductive, high strength and high bendability, has attracted great attention in recent years. The multi-touch effect can be achieved if a circuit pattern like a transistor array is marked on the carbon-based substrate so as to form a transparent carbon nanostructure-based thin film. The transparent carbon nanostructure-based thin film, having achieved the standards of 85% transmittance and 200 Ω/sq impedance, can be used in the touch panel of various electronic products.

The traditional IC processes use a photo resistor in a lithography step and a wet etching step to form the circuit pattern. However, the strong anti-corrosion of the carbon-based substrate makes the manufacturing process thereof complicated and time-consuming. Thus, the manufacturing cost of the carbon-based substrate is hard to be reduced and the carbon-based substrate cannot be widely used in various electronic products.

SUMMARY OF THE INVENTION

The invention is directed to a patterning method for a carbon-based substrate. The carbon-based substrate is etched by an oxygen-contained plasma at an atmospheric pressure, so that the process of patterning the carbon-based substrate is more efficient and more convenient.

According to a first aspect of the present invention, a patterning method for a carbon-based substrate is provided. The patterning method for the carbon-based substrate includes the following steps. The carbon-based substrate is provided. Under an open air environment, an atmospheric pressure plasma is produced from a plasma gas that includes mostly usually gas like oxygen, nitrogen, argon, clean dry air or mixed gas of them. The carbon-based substrate is etched by the atmospheric pressure plasma.

The invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a flowchart of a patterning method for a carbon-based substrate; and

FIGS. 2-7 respectively show the steps of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

The invention is exemplified by an embodiment below. However, the embodiment is for exemplification only, not for limiting the scope of protection of the invention. Besides, secondary elements are omitted in the embodiment for highlighting the technical features of the invention.

Referring to FIG. 1 and FIGS. 2-7. FIG. 1 shows a flowchart of a patterning method for a carbon-based substrate 100. FIGS. 2-7 show the respective steps of FIG. 1.

Firstly, the method begins at step S102, as indicated in FIG. 2, a carbon-based substrate 100 is provided. In the present embodiment of the invention, the carbon-based substrate 100 is exemplified by a transparent carbon nanostructure-based thin film like carbon nanotube or nano-graphite. The optical properties of the transparent carbon nanostructure-based thin film are similar to that of the indium tin oxide film (ITO film). The transparent carbon nanostructure-based thin film having high electron conductivity can be used to form a conductive film with high transparency. Therefore, the transparent carbon nanostructure-based thin film can be used in electronic devices such as displays and solar batteries, which require a transparent electrode, or used in photo-electrical elements such as transistors and sensors.

Next, the method proceeds to step S104, as indicated in FIG. 3, a hard mask 300 is provided. The hard mask 300 has a hollowed pattern 310. The hard mask 300 is made from metal, ceramic or glass. The hollowed pattern 310 is a predetermined etching pattern of the carbon-based substrate 100, wherein, the hollowed pattern 310 penetrates an upper surface 300a and a lower surface 300b of the hard mask 300, and an inner-sidewall 310a of the hollowed pattern 310 is a steep sidewall so that the atmospheric pressure plasma 500 (illustrated in FIG. 5) of the subsequent step can conveniently penetrate through.

In step S104, the inner-sidewall 310a of the hollowed pattern 310 is a steep sidewall; therefore, the hollowed pattern 310 of the hard mask 300 can be formed by ways of mechanical or chemical process, such as mechanical cutting, laser cutting, knife cutting, electric discharge machining or photo-etching.

Then, the method proceeds to step S106, as indicated in FIG. 4, the hard mask 300 is attached to the carbon-based substrate 100, wherein the hollowed pattern 310 exposes a portion of the carbon-based substrate 100. Whether the hard mask 300 contacts the carbon-based substrate 100 depends on the accuracy of the subsequent etching process. When the hard mask 300 contacts the carbon-based substrate 100, the hard mask 300 can be fixed by a detachable adhesive (or a tape) or by a mechanical fixing element.

As disclosed in steps S104 and S106, the material of the hard mask 300 is not the patterned photoresist or the patterned silicon nitride adopted in the semiconductor process. Moreover, the hard mask 300 already forms the hollowed pattern 310 before, not after, being attached to the carbon-based substrate 100.

Thus, after the etching process of the hollowed pattern 310 of the hard mask 300 is completed, the same hard mask 300 can be repeated used in several carbon-based substrates 100.

Afterwards, the method proceeds to step S108, as indicated in FIG. 5, an atmospheric pressure plasma 500 is produced from a plasma gas under an open air environment such as an atmospheric pressure or close to an atmospheric pressure.

The atmospheric pressure plasma 500 has cost advantage. In terms of equipment cost, the atmospheric pressure plasma 500 can do without the use of expensive and clumsy vacuum equipment. During the manufacturing process, the to-be-processed object is not subjected to the vacuum cavity, and is thus applicable to continual process. These features all contribute to reducing the manufacturing cost.

In terms of the components of the plasma gas for producing the atmospheric pressure plasma 500, the plasma gas at least includes oxygen, such as pure oxygen, mixed gas of nitrogen and oxygen, mixed gas of argon and oxygen and clean dry air (CDA).

In terms of the device for producing the atmospheric pressure plasma 500, the atmospheric pressure plasma 500 is produced from an arc jet plasma generator or a nonthermal dielectric barrier discharges (DBD) plasma generator for example.

In terms of the form of the atmospheric pressure plasma 500, the atmospheric pressure plasma 500 is a dotted atmospheric pressure plasma or a linear atmospheric pressure plasma for example.

Then, the method proceeds to step S110, as indicated in FIG. 6, the carbon-based substrate is etched by the atmospheric pressure plasma 500. The etching process uses the hard mask 300 as a shield, and only the portion of the carbon-based substrate 100 exposed on the hollowed pattern 310 is etched.

As disclosed above, the atmospheric pressure plasma 500 of the present embodiment of the invention is dotted or linear atmospheric pressure plasma. Thus, during the etching process, the carbon-based substrate 100 is etched by the atmospheric pressure plasma 500 through scanning.

As the atmospheric pressure plasma 500 of the present embodiment of the invention is produced from oxygen-based plasma gas, the atmospheric pressure plasma 500 contains oxygen plasma ions. When the oxygen plasma ions contact the carbon-based substrate 100, a chemical reaction is generated by oxygen ions and the carbon-based substrate 100 to form a vaporizable air (such as carbon dioxide). The carbon-based substrate 100 is etched by the chemical reaction. Thus, in the present embodiment of the invention, the etching between the atmospheric pressure plasma 500 and the carbon-based substrate 100 is mainly done through a dry chemical reaction rather than through a wet chemical reaction or an ion bombardment. Therefore, the etching method of the present embodiment of the invention has very high etching selectivity and very high etching rate as well.

Then, the method proceeds to step S112, as indicated in FIG. 7, the hard mask 300 is removed form the carbon-based substrate 100. As the hard mask 300 is not removed by destructive methods, and the atmospheric pressure plasma 500 will not destroy the hard mask 300 either, the hard mask 300 can be repeatedly used in several steps of etching the carbon-based substrate 100.

While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.

Claims

1. A patterning method for a carbon-based substrate, comprising:

providing a carbon-based substrate;

producing an atmospheric pressure plasma from a plasma gas under an open air environment, wherein the plasma gas comprises oxygen; and

etching the carbon-based substrate by the atmospheric pressure plasma.

2. The patterning method according to claim 1, wherein in the step of providing the carbon-based substrate, the carbon-based substrate is a transparent carbon nanostructure-based thin film.

3. The patterning method according to claim 1, wherein before the step of producing the atmospheric pressure plasma, the patterning method further comprises:

providing a hard mask having a hollowed pattern; and

attaching the hard mask to the carbon-based substrate, wherein the hollowed pattern exposes a portion of the carbon-based substrate.

4. The patterning method according to claim 3, wherein in the step of providing the hard mask, the hard mask is made from metal, ceramic or glass.

5. The patterning method according to claim 3, wherein in the step of providing the hard mask, the hollowed pattern is formed by way of a mechanical cutting.

6. The patterning method according to claim 3, wherein in the step of providing the hard mask, the hollowed pattern is formed by way of a laser cutting.

7. The patterning method according to claim 3, wherein after the step of etching the carbon-based substrate, the patterning method further comprises:

removing the hard mask from the carbon-based substrate.

8. The patterning method according to claim 1, wherein in the step of producing the atmospheric pressure plasma, the plasma gas further comprises nitrogen.

9. The patterning method according to claim 1, wherein in the step of producing the atmospheric pressure plasma, the plasma gas is a clean dry air (CDA).

10. The patterning method according to claim 1, wherein in the step of producing the atmospheric pressure plasma, the atmospheric pressure plasma is produced from an arc jet plasma generator.

11. The patterning method according to claim 1, wherein in the step of producing the atmospheric pressure plasma, the atmospheric pressure plasma is produced from a nonthermal dielectric barrier discharges (DBD) plasma generator.

12. The patterning method according to claim 1, wherein in the step of producing the atmospheric pressure plasma, the atmospheric pressure plasma is a dotted plasma.

13. The patterning method according to claim 1, wherein in the step of producing the atmospheric pressure plasma, the atmospheric pressure plasma is a linear plasma.

14. The patterning method according to claim 1, wherein in the step of etching the carbon-based substrate, the atmospheric pressure plasma etches the carbon-based substrate through scanning.

15. The patterning method according to claim 1, wherein in the step of etching the carbon-based substrate, the atmospheric pressure plasma and the carbon-based substrate generate a chemical reaction, so that a portion of the carbon-based substrate contacting the atmospheric pressure plasma forms a vaporizable air.