JPS6057628A - Formation of photo-resist pattern - Google Patents

Abstract

PURPOSE:To execute patterning with high accuracy on a form by providing a process in which a photosensitive resin layer is formed on a layer to be patterned with a stepped section through a polyvinyl phenol layer. CONSTITUTION:A layer to be patterned 12 with a stepped section is formed on a semiconductor substrate 11 on which a field oxide film 10 is shaped. A polyvinyl phenol layer 13 is formed on the layer 12. A photosensitive resin layer 14 containing bisazide as a photosensitizer is formed on the layer 13. Ultraviolet rays are projected selectively onto the layer 14, and a photo-mask patern is transferred. The whole is developed and treated. A layer 14 section not irradiated by ultraviolet rays and the layer 13 just under the layer 14 section are dissolved through the development treatment, and a photo-resist pattern 15 with high accuracy on a form can be obtained regardless of the stepped section 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for forming photoresist holes and turns.

[Technical background of the invention and its problems]

Conventionally, in order to form a scarlet mark of a predetermined pattern on a semiconductor substrate, a photosensitive resin layer of a predetermined shape is formed on the layer to be turned, a photosensitive agent is applied thereto, and after baking, ultraviolet light is applied. #
Transfer the photomask Tsuguturn onto this using a photomask,
Currently, a method for obtaining a car-shaped photoresist pattern is carried out after the first processing. The photoresist pattern thus obtained is masked and the patterned layer is etched to form the desired wiring pattern.

However, in such a method of forming a photoresist or turn, if there is a step in the turning layer, the thickness of the photosensitive resin layer formed thereon depends on the thickness of the photoresist layer to be turned. It becomes thicker on the lower side of the layer and becomes lake-like on the upper side of p1. When a photoresist pattern is formed in this state, as shown in FIG.
I can do it. As a result, there was a problem that wiring and the like could not be formed with high shape accuracy.

In addition, if the layer to be patterned and the photosensitive resin layer cross the concave part of contact hole 89, the ultraviolet rays irradiated when transferring the photomask pattern to one can of photosensitive resin will be reflected and As shown, the shape of the photoresist groove 4 deteriorates within the recess 3. Further, a standing wave is generated by the reflected light of the incident ultraviolet light, and this development is further lengthened. As a result, photoresist pattern 4
There were problems such as wire breakage.

[Purpose of the invention]

The purpose of Kinei IJ is to provide a method for forming a photoresist pattern that can be used for patterning with high shape accuracy.

[Summary of the invention]

The present invention is a method for forming photoresist holes and turns, which includes a step of forming a photosensitive resin layer on a punched pattern layer via a polyvinylphenol layer, thereby making it possible to perform patterning with high shape accuracy.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described with reference to FIG. 1I.

As shown in Figure 3, an example is field oxidation 11jj
Aluminum is vapor-deposited on the semiconductor substrate 11 which has been formed to form a temporary turning crack 12 having steps.

Next, as shown in the same figure (B), a turning layer 1 is formed.
A polyvinylphenol layer J3 is formed on 2 by a rotating cloth method. At this time, when the thickness TI of the thin portion of the polyvinylphenol layer J3 was measured, it was approximately 0.3 μm, and the thickness T2 of the thick portion was approximately 0.7 μm.

Next, as shown in Figure C), the base polymer is polyvinylphenol in the polyvinylphenol layer 13,
A photosensitive resin 14 containing bisazide as a photosensitizer is formed and baked at a temperature of 80° C. for 20 minutes. At this time,
When the thickness of the photosensitive resin layer J4 was measured, it was approximately 1.0 μm over the entire area, and the surface was flat.

Next, the photosensitive resin bath 14 is selectively irradiated with ultraviolet rays using a phototransfer device to transfer the photomask pattern. Next, this is subjected to a development process for about 3 minutes using a 1 weight M% d solution of sodium 2 methyl ammonium hydroxide. By this development treatment, the portion of the photosensitive resin layer 14 that has not been irradiated with ultraviolet rays and the polyvinylphenol layer 1 immediately below it are
3 is dissolved, and as shown in FIG. 4, a photoresist pattern J5 with extremely high shape accuracy can be obtained regardless of the stepped portion J6. This photoregis)/J turn 15
The layer to be patterned 12 is etched and etched using the mask as a mask.
Ali L , when the photoresist pattern 15 was removed by single-cell plasma, a predetermined shape a'W If
I was able to connect the wiring with i'L.

Here 1. j? Polyvinylphenol has the following molecular structure.

In addition, the photosensitive resin layer 14 contains 2 osg of 3,3'-duazido diphenyl sulfone having the following molecular structure in polyvinylphenol.

In addition, the photosensitive resin layer J4 and the polyvinylphenol layer 13
is tetramethylammonium hydroxide 1
It has been experimentally confirmed that both materials dissolve at a dissolution rate of 0.6 μm/min in a wt% aqueous solution. Further, the photosensitive resin layer 14 may use a novolac resin as a base polymer and contain naphthoquinonediazide as a photosensitizer, in addition to the one in the embodiment. In this case, 2.5% of tetramethylammonium is used as the developer.
It has been experimentally confirmed that when a wt % aqueous solution is used, effects similar to those of the example can be obtained with a treatment time of about 1 minute.

Further, polyvinylphenol)@is' containing a dye having superior ultraviolet absorption properties consisting of coumarin 6 is formed on the layer to be patterned 12' having four parts 17 as shown in FIG. A photosensitive resin layer 14 was formed thereon, and when the same body as in the example was irradiated with ultraviolet rays and developed, the reflection of the ultraviolet rays was blocked and a predetermined shape was formed even within the recess 17, as shown in FIG. A retained photoresist pattern 15' could be obtained.

Note that the layer to be patterned 12 may be formed of any material other than aluminum.

〔Effect of the invention〕

As explained above, according to the method of forming a photorenost/main turn according to the present invention, it is possible to easily perform turns with a high degree of shape axis.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams showing defective shapes of photoresist R-turns formed by the conventional method; FIGS. FIG. 4 is an explanatory diagram showing a photoresist pattern formed by the method of the present invention, FIG. 5 is a cross-sectional view of a semiconductor substrate on which a layer to be patterned having recesses is formed, and FIG. 6 is a cross-sectional view of the same plate. FIG. 3 is a plan view of a photoresist pattern formed on a turning layer by the method of the present invention. 10...Field oxide film, l-...Semiconductor substrate,
12...Layer to be buttered, 13...Polyvinylphenol 1 so, J4...Photosensitive resin layer, J5...Photoresist noya turn, '6 River step 4. H5 minutes, l
7...Four parts.

Claims (4)

[Claims] (1) A step of forming a turning layer having steps on a semiconductor substrate, a step of forming a photosensitive resin layer on the turning layer via a polyvinylphenol layer, and a step of forming a photosensitive resin layer on the turning layer with steps. (prescribed photomask) for ultraviolet irradiation on top? A method for forming a photoresist pattern and a pattern, the method comprising the steps of transferring the pattern and developing and removing a predetermined area of the polyvinylphenol layer and the photosensitive resin. (2) The method for forming a photoresist pattern according to claim 1, wherein the polyvinylphenol layer contains a dye with excellent ultraviolet absorbability. (3) The method for forming a photoresist pattern according to claim 1 or 2, wherein the pace polymer of the photosensitive resin layer is a novolac resin, and the photosensitizer is quinonediaside. (4) Is the pace polymer of the photosensitive resin layer 73? i? How to form a turn.