KR20010058695A - Method for eliminating bubble in an bottom anti reflective coating - Google Patents

Abstract

PURPOSE: A method for removing bubbles is provided to be capable of forming a uniform bottom anti-reflective coating(BARC) film on a wafer by controlling the rotation time and rotation speed of a spin chuck to efficiently remove bubbles generated in the BARC film. CONSTITUTION: In a method for removing bubbles, the spin chuck rotates at a very low speed(201). The spin chuck is rotated at the rate of 10-40 RPM for 1.0 second(202). The spin chuck is rotated at the rate of 20-50 RPM for 9.0 second so that a BARC solution can be slowly applied to a wafer(203). The spin chuck is rotated at the rate of 30-80 RPM for 25.0 second so that the BARC solution can reach an edge of the wafer(204). The spin chuck is rotated at the rate of 50-100 RPM for 3.0 second so that the BARC solution reached the edge of the wafer can be removed(205). The spin chuck is rotated at the rate of 200-300 RPM for 9.0 second so that a BARC film of the wafer can be uniformly coated while removing the BARC solution toward a catch cup(206). The spin chuck is rotated at the rate of 3970 RPM for 20.0 second so that a desired thickness of the wafer(207) can be formed.

Description

METHOD FOR ELIMINATING BUBBLE IN AN BOTTOM ANTI REFLECTIVE COATING}

The present invention relates to a bubble removing method of the bottom anti-reflective coating (abbreviated as "anti-reflective coating"), in particular to remove the bubbles (bubble) generated in the BARC by adjusting the rotation time and rotation speed of the spin chuck step by step. It's about how to do it.

In general, a semiconductor device has a form in which films having various patterns (for example, a silicon film, an oxide film, a field oxide film, a silicon nitride film, a polysilicon film, a metal wiring film, etc.) are stacked in a multilayer structure. In manufacturing the device, various processes such as a deposition process, an oxidation process, a photolithography process, an etching process, a cleaning process, a rinse process, and the like are required.

In the above-described process, a BARC (for example, photoresist) film formed on a wafer through a photolithography process in a semiconductor device manufacturing process is used for etching an insulating film, a conductive film, or the like formed on the wafer in an arbitrary pattern. Used as a etch resistant mask, this requires coating equipment to evenly apply BARC on the wafer.

Here, the coating equipment is a method of applying a BARC film having a uniform thickness on the wafer by dropping the BARC on a horizontal wafer, then rotating the wafer at a high rotational speed, for example, a rotational speed close to 1000 rpm.

That is, the BARC coating during the wafer rotation generates radial bubbles and, after etching the gate pattern, not only does not have sufficient BARC effect due to the bubbles made in the BARC during etching, but also the active area as shown in FIG. 3. There was a problem in that a hole (mo) pit (A) was formed in the transistor, resulting in a defect of the transistor, resulting in a low yield.

Accordingly, the present invention has been made to solve the above-described problems, the object of which is to adjust the rotation time and rotation speed of the spin chuck step by step to efficiently remove the bubbles (bubble) generated in the BARC uniform BARC on the wafer To provide a bubble removing method of BARC to form a film.

In the present invention for achieving the above object, the bubble removing method of the anti-reflection film (BARC) has a spin chuck that rotates by mounting the wafer, the method of dispensing (BAP) solution BARC on the wafer seated on the spin chuck A first process of rotating the spin chuck at a very low speed for a very short time; A second process of applying the BARC solution by rotating the spin chuck at a faster speed than the first process for a longer time than the first process; For a longer time than the second process, rotating the spin chuck at the same speed as the second process so that the BARC solution reaches the wafer edge; A fourth process of rotating the spin chuck at a faster speed than the third process to remove the BARC solution that has reached the edge for a time longer than the first process and shorter than the second process; During the same time as the second process, the fifth process of rotating the spin chuck at a higher speed than the fourth process to uniformly coat the BARC solution; It is characterized by consisting of a sixth process to form the thickness of the wafer by rotating the spin chuck at a faster speed than the fifth process in a time longer than the fifth process and shorter than the third process.

1 is a side cross-sectional view of a coating apparatus for performing a bubble removing method of the anti-reflection film according to the present invention,

2 is a detailed flowchart for explaining a bubble removing method of the anti-reflection film according to the present invention,

3 is a view illustrating a hole phenomenon generated in an active area according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

101: spin chuck 103: catch cup

105: supply pipe 107: discharge nozzle

109: Wafer

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a side cross-sectional view of a coating apparatus for performing a bubble removing method of an anti-reflection film (BARC) according to the present invention, containing a spin chuck 101 and a BARC solution connected to a spin motor (not shown) through a rotating shaft. The main includes a discharge nozzle 107 connected through a catch cup 103 and a supply tube 105 to a BARC supply, not shown, and a wafer seated in a wafer holder (not shown) fixed to the spin chuck 101 ( 109).

Referring to the figure, the spin chuck 101 seats (or mounts) the wafer 109, and the discharge nozzle 107 connected to the tip of the supply pipe 105 in a state where the wafer 109 is seated in the wafer holder. The spin chuck 101 rotates step by step according to the driving force from a spin motor (not shown) when a BARC solution (ie, a solution having a constant viscosity) is supplied to the center portion of the wafer 109 through the step (step 201). ).

That is, the spin chuck 101 is rotated at a rotation time and a rotational speed of a total of 6 processes to form a uniform BARC film on the wafer 109 while removing bubbles. As a first process, the spin chuck 101 is During a time period of 1.0 second, the motor is rotated at a speed of 10 to 40 (eg, 20) RPMs (step 202).

In a second process, the spin chuck 101 is rotated at a speed of 20-50 (eg, 40) RPM for a time of 9.0 seconds to slowly apply the BARC solution to the wafer 109 (step 203).

In a third process, spin chuck 101 is rotated at a speed of 30 to 80 (eg, 40) RPM for a time of 25.0 seconds to allow BARC solution to reach the edge of wafer 109 (step 204). .

In a fourth process, the spin chuck 101 is rotated at a speed of 50-100 (eg 80) RPM for 3.0 seconds to remove the BARC solution that has reached the edge of the wafer 109 (step 205). ).

In a fifth process, the spin chuck 101 is rotated at a speed of 200 to 300 (eg 230) RPM for a 9.0 second time to uniformly remove the BARC film of the wafer 109 while removing the BARC solution toward the catch cup 103. Coating. At this time, most of the BARC solution leaving the wafer 109 by the centrifugal force generated by the speed of the 200 ~ 300 RPM of the spin chuck 101 hits the inner wall of the catch cup 103 and flows down the inner wall, the catch Some of the BARC solution that hit the inner wall of the cup 103 is splashed back toward the wafer 109 by the impact repulsive force with the inner wall and directed toward the wafer 109. Thus, the BARC solution that faces the wafer 109 They fall in the direction of the outlet (not shown) (step 206).

In a sixth process, spin chuck 101 is rotated at a speed of 3970 RPM for a time of 20.0 seconds to form the desired thickness of wafer 109 (step 207).

Accordingly, the BARC solution is gradually diffused and developed step by step from the center of the wafer to the edge by the rotation centrifugal force, thereby forming a uniform BARC film on the wafer 109 while completely removing bubbles generated on the wafer 109. will be.

The above process is summarized as a table.

Step Time Speed RPM Dispense One 1.0 20 0 2 9.0 40 1 (application) 3 25.0 40 0 4 3.0 80 0 5 9.0 230 8 (spray-back) 6 20 3970 0

As described above, the present invention adjusts the rotation time and rotation speed of the spin chuck step by step to efficiently remove bubbles generated in the BARC to form a uniform BARC film on the wafer to prevent a decrease in production yield. It can be effective.

Claims (7)

A method of dispensing an anti-reflection film (BARC) solution on a wafer seated on the spin chuck, the spin chuck having a spin chuck mounted thereon, the method comprising: A first process of rotating the spin chuck at a very low speed for a very short time; A second process of applying the BARC solution by rotating the spin chuck at a faster speed than the first process, for a longer time than the first process; For a longer time than the second process, a third process of rotating the spin chuck at the same speed as the second process so that the BARC solution reaches the wafer edge; A fourth step of removing the BARC solution that has reached the edge by rotating the spin chuck at a higher speed than the third step for a time longer than the first step and shorter than the second step; A fifth process of uniformly coating the BARC solution by rotating the spin chuck at a higher speed than the fourth process during the same time as the second process; And a sixth step of forming the thickness of the wafer by rotating the spin chuck at a faster speed than the fifth step for a time longer than the fifth step and shorter than the third step. The method of claim 1, wherein in the first step, the spin chuck is rotated at a speed of 10 to 40 RPM at a time of 1.0 second. The method of claim 1, wherein the second process rotates the spin chuck at a speed of 20 to 50 RPM at a time of 9.0 seconds. The bubble removing method of the anti-reflection film according to claim 1, wherein the third process rotates the spin chuck at a speed of 30 to 80 RPM at a time of 25.0 seconds. The bubble removing method of the anti-reflection film according to claim 1, wherein the fourth step rotates the spin chuck at a speed of 50 to 100 RPM at a time of 3.0 seconds. The method of claim 1, wherein the fifth process comprises rotating the spin chuck at a time of 9.0 seconds and at a speed of 200 to 300 RPM. The method of claim 1, wherein the sixth process rotates the spin chuck at a speed for forming a desired thickness of the wafer at a time of 20.0 seconds.