JPS6032203A - Method of patterning transparent thin film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the invention.
It is concerned with patterning methods for transparent thin films such as o2, and in particular relates to improvements in the lift-off method.

In the liquid crystal display panels that have been appearing on the market recently, lightning or polarization occurs on transparent substrates such as glass. Transparent conductive thin films are often used as part of the wiring. Those transparent conductive films are mainly I
TQ and 5n02 are used, but when buttering toi etc., side etching tends to occur due to poor adhesion with the resist. It has become.

One way to completely solve this problem is the lift-off method. - The lift-off method is a method in which, for example, a resist is patterned on a substrate, a TO is deposited using a svanta or the like, and then the resist is removed to pattern the TO. (2) Since the TO etching step is not required, there are advantages in that the number of steps is reduced and the dimension f* degree is improved. On the other hand, to remove the TO on the resist, it is done by dissolving the resist with an organic solvent such as acetone, a strong acid such as concentrated nitric acid, or a special resist stripping liquid, so the peeled TO can be reused. There is a problem with adhesion.

The present invention has been made in order to prevent redeposition using the conventional lift-off method. Alternatively, by using a film that absorbs light, ■ Negative resist coated on the surface after deposition of a transparent thin film such as To. Exposure from the back side of the substrate to cover only the necessary parts of the transparent thin film with resist, and remove the lit-off@transparent thin film. Lift-on is carried out after most of the lifted-off transparent thin film is removed.Therefore, re-deposition of the lifted-off transparent thin film can be almost eliminated, and it also has the advantage of microfabrication of the lift-off method.

The present invention will be explained in detail below along with the drawings.

FIGS. 1(a) to 1(e) are process cross-sectional views for explaining one embodiment of the present invention. FIG. 1(a) shows glass.

This is a cross section of an opaque first thin film 10 patterned on a transparent substrate 1 made of quartz, sapphire, or the like. The first thin film 10 is M
Metals such as, semiconductors such as amorphous 51 (a-sl) and polycrystalline 81, resists containing original absorbents, etc. are used. Thereafter, as in No. 1j9(b), transparent thin films 20 and 21 such as ■TQ, 5iQ2, etc. are deposited by sbanking, vapor deposition, or the like.

Preferably, this deposition is a directional deposition (deposition with poor step coverage), with l1 of the transparent thin film 20.21
4 is made thinner than that of the first thin film 10. Figure 1 (C)
The cross section of the substrate 1 is shown after coating the surface with a negative resist.
This is when the film is developed by irradiating light such as ultraviolet light from the back side of the film. Since the resist on the first thin layer 10 cannot be fully exposed, it is removed by development and the resist 51 remains on the transparent thin film 21 directly above the substrate 1.

FIG. 1(d) shows a cross section in which the transparent thin film 20 on the exposed first thin pattern 10 is etched and removed, and FIG. 1<e> shows a cross section in which the first thin film 10 is also removed. .

As described above, since the transparent thin film 20 on the first thin film 10 is removed by etching, there is no fear of re-deposition, and the patterning accuracy of the transparent thin film 21 is the same as that of the lift-off method. Even if a normal resist is used as the first thin film 10, the intensity of transmitted light from the back side of the substrate 1 will be lower than the first thin film 10.
The present invention can be applied by selecting the conditions.

FIGS. 2(a) to 2(f) are process cross-sections of another embodiment of the present invention. In this embodiment, the first thin film consists of an upper opaque layer 10 and a lower layer 11. FIG. 2(a) shows a cross section of the upper layer opaque thin film 10 that has been patterned, and FIG. 2(b) shows the lower layer Ii using the upper layer thin film 10 as a mask.
! This is a cross section obtained by over-etching 411.

Due to over-etching, over-etching occurs on the soil 1d thin m 1o. FIG. 2(C) shows the transparent thin film 20.2.
1 was deposited to a thickness equal to or less than that of the lower thin film 11 and 7' (cross section is shown).

The transparent thin films 20 and 21 can be completely separated by the overhang of the upper thin film 100.

FIG. 2(d) shows a cross section coated with a negative resist, and when light is irradiated from the back side of the substrate 1 and development is stopped, the negative resist remains only on the transparent thin layer 11A21 that is to be left.
Figure (e)). After that, as shown in Figure 2 (bl), the transparent thin film 2
0 is removed by etching, and the upper thin film 10 and resist 61 are removed. The lower thin film 11 may be removed if necessary,
The upper thin film 10 can be used for other purposes (for example, as part of wiring) without removing it.

The upper thin film 10 can be made of a metal, a semiconductor, a resist, etc., and the lower thin film 11 can be made of a 5iOz film, a thin film, a resist, etc. A film that can be etched using M1o as a mask can be used. It is also possible to make the lower thin film 11 opaque, contrary to the example shown in FIG. In the example shown in FIG. 2, the transparent thin films 20 and 21 can be completely separated, making it easy to lift off, and the edges of the remaining transparent thin film 21 can be easily tapered, which is advantageous for processing after the next step. ing.

As described above, the present invention is an effective method for patterning a transparent thin film on a transparent substrate.
, can also be applied to thin gold maple detectives, etc.

[Brief explanation of the drawing]

FIGS. 1(a) to (e) are process sectional views according to one embodiment of the buttering method of the present invention, and FIGS. 2(a) to <+> are process sectional views according to another embodiment of the present invention. It is a process sectional view. 1... Transparent substrate 10... Opaque 4 parts 11...
Lower layer 1st light smell 20,21...Transparent light ki50゜51
...Negative resist or higher Applicant: 2nd I6 Co., Ltd. Figure 1 (α) I Figure 1 (b) l Figure 1 (e) Figure 2 (α) /l f f

Claims (2)

[Claims] (1) Depositing an opaque or light-absorbing first thin film on a transparent insulating substrate, patterning it into a desired shape, and exposing a part of the substrate surface; a step of depositing a transparent thin film thereon, a step of coating a negative resist on the transparent thin film, a step of irradiating the source from the back side of the substrate to expose the resist in a portion other than the first thin film, and leaving it by a development process. A method for patterning a transparent thin film, comprising: a step of removing the transparent thin film 1 on the exposed first thin film; and a step of removing the negative resist. (2) the first thin film is composed of at least two layers;
At least a part of N's 4 layers is an opaque or light-absorbing thin film, and unless two layers of thin films are buttered, the upper thin film is used as part of a mask after buttering the upper thin film. 2. The method of buttering a transparent thin film according to claim 1, wherein the thin film is over-etched and buttered to form an overhanging shape of the upper thin film.