JP2593465B2 - Liquid processing equipment for semiconductor wafers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a liquid processing apparatus for semiconductor wafers, and more particularly, to a liquid processing apparatus used for resist coating and development in photolithography of semiconductor wafers. Is done.

(Prior Art) FIG. 5 is a cross-sectional view of a liquid processing apparatus used for applying a resist to a semiconductor wafer or performing development or the like. In the figure, 101 is a semiconductor wafer mounting rotary table, on which a semiconductor wafer 102 is mounted on the upper surface, and is suction-fixed under reduced pressure.
The shaft 101a extending downward is connected to a rotation drive mechanism 101b, for example, a motor and a rotation speed adjusting / switching unit. Then 103
Is an outer container, which surrounds the semiconductor wafer mounting rotary table 101 and has a cup shape. A liquid drain port 103a is provided at a lower part thereof, and a lid body 103b is provided at an upper part thereof. Also,
Above the semiconductor wafer mounting rotary table 101, a processing liquid injection port 104 is disposed so as to face the center of the semiconductor wafer mounted on the rotary table.

The drain port 103a is connected to the processing waste liquid reservoir 105 and is connected to an external exhaust dust (not shown) to form a downward air flow in the outer container 103, and the semiconductor wafer 102
The mist of the processing liquid generated by the rotation of the semiconductor wafer, which is poured above, is put on the air flow and collected.

(Problems to be Solved by the Invention) In the above described prior art, the size and shape of the surrounding container
Due to the exhaust capability (the number, position, and exhaust speed of the exhaust ports) of the drain ports provided therein, a "bounce" of a processing liquid such as a resist or a developing liquid generated when the semiconductor wafer rotates is generated. Due to this "bounce", the processing liquid adheres to the upper main surface of the semiconductor wafer, and has a serious disadvantage that it adversely affects the resist coating film and the state of development.

The present invention has been made in view of the above-mentioned problems in the related art,
An object of the present invention is to provide an improved structure of a liquid processing apparatus for a semiconductor wafer.

[Configuration of the invention]

(Means for Solving the Problems) A liquid processing apparatus for a semiconductor wafer according to the present invention includes a semiconductor wafer mounting rotary table on which a semiconductor wafer is mounted and rotated by a rotation drive mechanism, and a semiconductor wafer mounting rotary table. An outer container that surrounds the container and has a drainage port at a lower portion, a processing liquid pouring means disposed above and directed toward the semiconductor wafer mounting rotary table, and an inner surface of the outer container A cleaning liquid flowing means provided at an upper edge of the outer container to cause the cleaning liquid to flow down, and the cleaning liquid flowing means is a loop-shaped cleaning liquid pool provided inward from the inner side surface of the outer container. And a through hole in which a part of a lower end is inclined from the cleaning liquid pool to the inner surface and a part of the lower end is in contact with the inner surface.

(Operation) In the present invention, in order to prevent the processing liquid from re-adhering to the semiconductor wafer due to "bounce" on the outer container, the liquid flows down to the inner wall of the outer container.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. In the description, portions that are the same as those in the related art are denoted by the same reference numerals in the drawings, and description thereof is omitted.

In the apparatus of the embodiment shown in FIG. 1, an outer container 11 is provided with a washing liquid flowing down means 12 at an upper edge thereof. The cleaning liquid flow-down means 12 is provided at the upper edge of the surrounding container 11 with a cleaning liquid pool 12a.
Is formed as a loop, and a through hole 12a is provided below the lower wall 12a in contact with the inner wall so that the cleaning liquid flows down along the inner wall of the outer container 11. Then, a cleaning liquid, for example, pure water, city water, a solvent, or the like is selected depending on the type of the processing liquid to be used.

 An embodiment of an example of a positive register will be described below.

(I) Resist coating Pretreatment baking and HMDS
When a resist is applied to a (hexamethylene disilazane) -treated semiconductor wafer, the semiconductor wafer 102 is placed on the upper surface of the rotary table 101 for mounting the semiconductor wafer.
Is held under reduced pressure, and as shown in FIG.
Apply a clean spin at 5000 RPM for 2-3 seconds. The clean spin removes dust attached in various steps before coating. Thereafter, while the semiconductor wafer is stationary, the dropping of the resist is started. At least at the same time as the dropping of the resist, the flow of the cleaning liquid to the inner side wall is started. The cleaning liquid in this case is an organic solvent that dissolves the positive resist, such as EC
A (ethyl cellosolve acetate), acetone and the like. The flow of the cleaning liquid is continued until the completion of 5 seconds of an example during the low-speed rotation and 30 seconds of the example during the subsequent high-speed rotation.

(Ii) Development After the semiconductor wafer coated with the resist film as described above is subjected to pre-baking and exposure, as shown in FIG. Choline of a developing solution is poured for 20 seconds, and then pure water of a rinsing solution is poured for 15 seconds from a processing solution inlet 104 to perform development. After completion of the rinsing, rotation for drying is performed for 10 seconds as an example, but the flow of the cleaning liquid may be stopped about 3 seconds after the rinsing is completed.

Note that, for a negative resist, xylene, n-peptane, or the like is used as a cleaning liquid for resist coating, and butyl acetate or the like is used for development.

〔The invention's effect〕

According to the present invention, the defect rate of about 2.6% caused by the "bounce" of a processing solution such as a resist or a developing solution onto a semiconductor wafer is completely eliminated, and this significantly contributes to improvement in productivity and quality.

Further, the present invention has an advantage that it can be realized without requiring significant modification of the conventional device.

Further, according to the present invention, there is an advantage that the cleaning liquid flowing down along the inner surface of the outer container can be made uniform along the periphery of the inner surface. That is, even though the cleaning liquid pool is provided in a loop, the cleaning liquid cannot always be supplied at a uniform pressure along the periphery of the inner surface, so that the size (diameter) of the through-hole is experimentally adjusted. Achieved easily. Further, the structure of the through-hole has a remarkable advantage that even if the ejection pressure of the cleaning liquid increases, the flow of the cleaning liquid does not separate from the inner side surface of the container, thereby enabling a stable operation. In addition, there is a known method in which the flow of the cleaning liquid is performed by a slit. However, in this method, the flow amount is adjusted by adjusting the gap between the slits, which is extremely difficult in terms of work. Therefore, as described above, the configuration of the present invention is excellent.

[Brief description of the drawings]

1 to 3 relate to an embodiment of the present invention, and FIG.
FIG. 1a is a vertical sectional view of the device, FIG.
FIG. 2 is a diagram showing a schedule of a resist coating process, FIG. 3 is a diagram showing a schedule of a developing process, FIG. 4a is a vertical cross-sectional view of a conventional apparatus,
FIG. 4B is a cross-sectional view taken along the line AA of FIG. 4A. 11, 103 surrounding container 12 cleaning solution flow-down means 12a cleaning solution pool 12 through-hole 12c bottom end of through-hole 101 semiconductor wafer mounting rotary table 101b rotary drive mechanism 102 semiconductor wafer 103a …… Drain port 104 …… Injection port

Claims (1)

(57) [Claims] A semiconductor wafer mounting rotary table on which a semiconductor wafer is mounted and rotated by a rotary driving mechanism; an enclosing container surrounding the semiconductor wafer mounting rotary table and having a cup-shaped lower part with a drainage port; A processing liquid pouring means arranged above and directed to the semiconductor wafer mounting rotary table; and a cleaning liquid flowing means for flowing a cleaning liquid along the inner surface of the outer container. The means is provided with a cleaning liquid pool provided in a loop inward from the upper edge of the inner surface of the outer container, and a lower end of the cleaning liquid pool is inclinedly opposed to the inner surface and a part of the lower end is in contact with the inner surface. A liquid processing apparatus for a semiconductor wafer, comprising: