阅读说明：本技术 一种改善方片边缘涂胶风纹的方法 (Method for improving square sheet edge gluing wind marks ) 是由 张德强 朴勇男 边疆 王延明 蔺伟聪 于 2020-06-24 设计创作，主要内容包括：本发明公开了一种改善方片边缘涂胶风纹的方法,属于光刻胶涂胶工艺技术领域。该工艺采用了一种密闭型晶圆承片台,使得方片可以在封闭的腔体内进行涂胶工艺。该方法能够使在光刻胶涂覆过程中,方片表面可以均匀的形成一层胶膜,尤其对于8英寸方片,可使得边缘风纹降至5mm以内,使得方片利用率高达99％以上。(The invention discloses a method for improving the coating wind marks on the edges of square sheets, belonging to the technical field of photoresist coating processes. The process adopts a closed wafer bearing platform, so that the square sheet can be subjected to a gluing process in a closed cavity. The method can enable a layer of glue film to be uniformly formed on the surface of the square piece in the photoresist coating process, and particularly for 8-inch square pieces, the edge wind marks can be reduced to be within 5mm, so that the utilization rate of the square piece is up to more than 99%.)

1. A method for improving the coating wind lines on the edges of square sheets is characterized in that: the method is characterized in that in the process of coating photoresist on a square sheet, the flow effect of the photoresist outside the inscribed circle of the square sheet is accelerated by adjusting the annular flow field and the humidity inside a gluing cavity, so that the area of the wind veins at the edge of the square sheet is reduced; the method specifically comprises the following steps:

(1) sending the square plate into a gluing unit with a closed cavity, spraying photoresist at the center of the square plate by a gluing nozzle, driving the square plate to rotate by a plate bearing table, and uniformly coating the photoresist on the surface of the square plate;

(2) and after the glue is coated, sending the square sheet into a hot plate for baking to finish the curing of the photoresist.

2. The method for improving the square slice edge gluing air lines as claimed in claim 1, wherein: the gluing unit is provided with a closed cavity, the upper part of the wafer bearing table is arranged in the closed cavity, the closed cavity comprises an upper cover, and the upper cover is detachably connected with the closed cavity through a screw; the upper cover of the closed cavity is provided with a glue spraying opening, and the glue coating nozzle can translate at the glue spraying opening and spray photoresist to the square sheet.

3. The method for improving the square slice edge gluing air lines as claimed in claim 1, wherein: the coating thickness of the photoresist (thick film photoresist) is 1-3 mu m.

4. The method for improving the square slice edge gluing air lines as claimed in claim 1, wherein: in the step (1), in the photoresist coating process, the moving speed of a gluing nozzle is 100-150 mm/s, the glue spraying amount is 2-5 ml, the glue spraying speed is 0.5-2 ml/s, and the rotating speed of a square sheet (a sheet bearing table) is 500-3500 r/min.

5. The method for improving the square slice edge gluing air lines as claimed in claim 1, wherein: in the step (2), the baking temperature of the hot plate is 90-120 ℃, and the baking time is 90-120 s.

6. The method for improving the square slice edge gluing air lines as claimed in claim 1, wherein: when the square piece is an 8-inch square piece, the width of the glue-coated air lines on the square piece is less than 5mm after the square piece is processed by the method.

Technical Field

The invention relates to the technical field of photoresist coating processes, in particular to a method for improving coating wind marks on edges of square sheets.

Background

The photoetching process is the most important process step in the whole manufacturing process flow of the microelectronic integrated circuit, mainly comprises gluing, exposure, development and the like, and along with the increase of the wafer size and the improvement of the utilization rate of the wafer, the requirement for reducing edge defects in the gluing process is also improved.

In the display field, the rapid development of OLED products makes the glass substrate become one of the important raw materials of the display panel, and the glass substrate mainly has square substrates, so how to improve the utilization rate of the square sheets and the uniformity of coating the surfaces of the square sheets become key factors that restrict the use of the square sheets.

A large number of researches show that the poor gluing uniformity and low utilization rate of the square sheet mainly come from wind veins generated at the edge of the square sheet, the starting position of the wind veins is located at an inscribed circle of the square sheet, good gluing uniformity can be obtained in the inscribed circle, and annular wind veins can be seen outside the inscribed circle. The main cause of the wind lines is the difference of centrifugal force applied to irregular areas outside the inscribed circle.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a method for improving the square sheet edge gluing air lines, which accelerates the flow effect of photoresist outside the circle of the inner circle of the square sheet by improving the annular flow field and the humidity of the inner part of the gluing cavity, thereby greatly improving the square sheet edge air line condition, reducing the width of the square sheet air lines from 20-45mm to within 5mm under the same process condition, and improving the square sheet utilization area to more than 99%.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for improving the edge of a square piece to glue the wind lines, said method is to carry on the course to coating photoresist to the square piece, through regulating the inner annular flow field of the glue spreading cavity and humidity, has accelerated the flow effect of photoresist in the square piece inside the tangent circle, thus reduce the area of wind lines of edge of the square piece; the method specifically comprises the following steps:

(1) sending the square plate into a gluing unit with a closed cavity, spraying photoresist at the center of the square plate by a gluing nozzle, driving the square plate to rotate by a plate bearing table, and uniformly coating the photoresist on the surface of the square plate;

(2) and after the glue is coated, sending the square sheet into a hot plate for baking to finish the curing of the photoresist.

The gluing unit is provided with a closed cavity, the upper part of the wafer bearing table is arranged in the closed cavity, the closed cavity comprises an upper cover, and the upper cover is detachably connected with the closed cavity through a screw; the upper cover of the closed cavity is provided with a glue spraying opening, and the glue coating nozzle can translate at the glue spraying opening and spray photoresist to the square sheet.

The coating thickness of the photoresist (thick film photoresist) is 1-3 mu m.

In the step (1), in the photoresist coating process, the translation speed of a gluing nozzle is 100-150 mm/s, the glue spraying amount is 2-5 ml, the glue spraying speed is 0.5-2 ml/s, and the rotating speed of a square sheet (a sheet bearing table) is 500-3500 r/min.

In the step (2), the baking temperature of the hot plate is 90-120 ℃, and the baking time is 90-120 s.

When the square piece is an 8-inch square piece, the width of the glue-coated air lines on the square piece is less than 5mm after the square piece is processed by the method.

The invention has the following advantages and beneficial effects:

the invention provides a gluing process for coating a volatile photoresist with a small viscosity coefficient on the surface of a square sheet, which adopts a closed cavity, and on one hand, the closed cavity avoids the influence of external wind flow, increases the internal humidity of the cavity and ensures that the mobility of the photoresist outside an inscribed circle of the square sheet is stronger; on the other hand, the closed cavity rotates along with the rotation of the square plate, and the internal airflow also rotates along with the closed cavity to form an annular flow field, so that the flowing effect of the photoresist on the edge of the square plate is accelerated, and the effect of improving the wind marks on the edge of the square plate is achieved.

Drawings

Fig. 1 is a schematic front view of a gluing unit used in the present invention.

Fig. 2 is a schematic top view of the gluing chamber according to the invention.

FIG. 3 is a graph showing the results of example 1.

Fig. 4 is a schematic view of a conventional gluing unit.

Fig. 5 is a graph showing the results of comparative example 1.

Detailed Description

The invention is described in detail below with reference to the accompanying drawings and examples.

The invention provides a method for improving the coating air lines on the edges of square sheets, and a schematic diagram of a coating unit in the process is shown in figure 1. The gluing unit is provided with a closed cavity, the upper part of the sheet bearing table is arranged in the closed cavity, the 8-inch glass substrate square sheet is placed on the sheet bearing table, and the sheet bearing table can drive the square sheet to rotate clockwise; the glue nozzle can translate above the cavity and spray photoresist.

The closed cavity comprises an upper cover which is detachably connected with the closed cavity through a screw; the upper cover of the closed cavity is provided with a glue spraying opening, and the glue coating nozzle can translate at the glue spraying opening and spray photoresist to the square sheet.

The square piece gluing process in the following embodiment is performed on the surface of a 8-inch glass substrate square piece coated with a photoresist with a thickness of 1-3 μm.