JP3194815B2 - Resist coating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing method and apparatus, and more particularly, to a resist coating process.

[0002]

2. Description of the Related Art As a conventional resist coating method, there are a spin-rotation type coating apparatus, a roller coating apparatus and the like. Among them, a spin-rotation type coating apparatus is an apparatus that forms a uniform resist film on a substrate by dropping a resist on a horizontal semiconductor substrate and rotating the substrate. At present, this method is generally used. Has been adopted. When applied by this method, uniformity and stability of the resist film thickness and generation of dust mist can be suppressed, and a considerably high yield can be obtained.

[0003] Regarding the conventional spin-rotation coating method,
This will be described with reference to the perspective view of the conventional spin-rotation type coating apparatus shown in FIG. The wafer 61 is vacuum-adsorbed on the stage 62. The stage 62 is connected to a spin motor 63, and has a structure for performing a rotary motion. Above the wafer 61, a nozzle 64 for dropping a resist is moved from a standby position by a nozzle driving mechanism 65, and approaches the wafer 61. When the nozzle 64 receives the supply of the resist, the nozzle 64 drops the resist on the wafer 61. The wafer 61 adsorbed on the stage 62 is, for example, 2000
The resist is dried by rotating the resist at 3000 rpm for about 20 to 30 seconds to obtain a resist having a desired film thickness on the wafer 61. The film thickness to be formed is controlled by the number of rotations.

However, when a resist is applied to a wafer using a conventional spin-rotation type coating apparatus, an expensive resist is shaken by 90% or more during rotation.
More than ten times more resist is required than the resist required on the wafer, and there is a problem that it becomes difficult to obtain a uniform film thickness as the size of the wafer increases. In order to place the highest priority on the reliability of the formed resist film, there is a problem that it is difficult to improve the number of wafers processed per unit time in the apparatus, that is, the throughput.

[0005]

As described above, conventionally, when a resist is applied by using a spin-rotating apparatus, there is a problem that the resist must be discarded unnecessarily. The present invention has been made in view of the above-described problems, and provides an apparatus for reducing the amount of resist used and improving the throughput.

[0006]

In order to achieve the above object, the present invention provides a stage for mounting a wafer, a rotating mechanism for rotating the stage, a drip nozzle for dropping a resist on the wafer, A drying nozzle for blowing a drying gas of the resist onto the wafer, and a dropping port of the dropping nozzle and a blowing port of the drying nozzle are each formed in a long groove shape in the diameter direction of the wafer,
A resist coating apparatus is provided in which a part of the groove of the dropping nozzle is positioned on a center point of the wafer when the groove is close to the wafer, thereby performing resist coating.

[0007] The dropping port and the blowing port have a width equal to or larger than the radius of the wafer, and one end of a groove of the dropping port is located at a center point of the wafer, and the wafer is rotated once or Provided is a resist coating apparatus characterized in that the resist is transferred and dried by rotating the resist further.

[0008] Further, the drip port and the blow-out port have a diameter equal to or greater than the diameter of the wafer, and the midpoint of the groove of the drip port is located at the center of the wafer. A resist coating apparatus characterized in that the resist is transferred and dried by rotating it two or more times.

In addition, an inert gas is used as the drying gas, and the wafer is rotated by the rotating mechanism to drop and transfer the resist through the dropping port, and thereafter, dry the gas from the drying nozzle. A volatilization and drying of the solvent in the resist to obtain a predetermined film thickness.

[0010]

According to the resist coating apparatus of the present invention configured as described above, unnecessary swinging of the resist during rotation is reduced, and the resist is coated with a constant thickness regardless of the size of the wafer. It becomes possible to do.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A spin-rotation type coating apparatus and a resist coating method according to an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view showing one embodiment of a spin-rotation type coating apparatus according to the present invention. With reference to FIG. 1, a spin rotation type coating apparatus and a resist coating operation will be described. First, the wafer 11 is moved to the stage 1
2 and fixed on the stage 12 by vacuum suction. The stage 12 is connected to a spin motor 13 therebelow, whereby the wafer 11 rotates.

A dropping nozzle 14 for dropping a resist is provided above the wafer 11. A dropping nozzle driving mechanism 15 connected from the dropping nozzle 14 via a resist insertion pipe 16 is provided.
Thereby, it is possible to move from the standby position and approach the vicinity of the wafer 11. This operation can be finely adjusted according to the wafer and purpose. Also,
The dripping nozzle 14 has a rectangular parallelepiped shape whose longitudinal direction is set parallel to the upper surface of the wafer 11.

When the dripping nozzle 14 receives the supply of the resist from the insertion opening of the resist insertion tube 16 on the side of the dripping nozzle drive mechanism 15, the resist is moved into the resist insertion tube 16 in the direction of arrow (A) in FIG. To move the drip nozzle 1
4 spreads in the longitudinal direction, and is dropped on the wafer along a groove formed in a slit shape in the longitudinal direction below the dripping nozzle 14. At this time, the dropping range is determined by the length of the groove of the dropping nozzle 14, which is initially set according to the wafer type so as to have a length commensurate with the radius or diameter of the wafer 11. Also,
The film thickness after applying the resist is proportional to the thickness of the groove located at right angles to the length of the groove corresponding to the diameter of the wafer. It is possible.

The drip nozzle 14 close to the wafer 11
Is set so that the groove is positioned on a line passing through the center of the wafer 11 and both ends are located at the outer end portions of the wafer 11. In the case of a dropping nozzle 14 having a groove corresponding to the radius of the wafer, one end of the dropping nozzle 14 is set at the center of the wafer 11 and the other end is set at the outer end of the wafer 11.

As with the dripping nozzle 14, the drying nozzle 17
Is positioned on the wafer 11 together with the resist dropping nozzle 14 from the drying nozzle driving mechanism 18 via the drying gas insertion pipe 19, and is positioned so as to be close to the dropping nozzle 14. At this time, the drying nozzle 17 is moved to the dripping nozzle 1.
4 and may be driven by the same drive system as the drip nozzle 14.

When the above-mentioned positioning is completed, the resist and the dry gas are supplied to complete the coating process. The process is roughly classified into two types. Hereinafter, each of them will be described.

First, in the first method, at the same time that the resist is dropped from the groove of the dropping nozzle 14, the stage 12 starts to rotate at a low speed by the spinning motor 13 which is a rotating mechanism.
When the setting of the dropping nozzle 14 is a radius, the rotation is one rotation, and when the setting is a diameter, the rotation is 回 転 rotation or more.
1 Transfer the resist to the entire surface. At the same time as the start of the dropping of the resist, the drying gas is supplied from the drying gas insertion port on the side of the drying nozzle drive mechanism 18 through the drying gas insertion pipe 19, and an inert gas such as N ₂ is blown out of the drying nozzle 17 Immediately start drying the dropped resist. This rotation is performed at a low speed of, for example, 1 rpm, and the supply of the resist is completed by one rotation when the length of the groove is a radius and by one half rotation when the groove is a diameter according to the setting of the dripping nozzle 14. However, the drying step may be continued one or two more times, that is, two to three times in total. As a result, the process time, which conventionally took 1 minute or more at 2000 to 3000 rotations, is greatly reduced, low power consumption, a uniform film thickness regardless of the wafer size, and an improvement in throughput. It can be a realized step.

Next, as a second method, at a low speed such as 1 rpm, if the length of the groove of the drip nozzle 14 is a radius, 1
After the necessary amount of resist has been transferred by rotation or more, or 1/2 rotation or more in the case of a diameter, the supply of the resist is stopped, and then only drying is performed. In this case, the drying process includes two processes, that is, a process in which a dry gas is blown at 1 rpm to perform two to three rotations, and a process in which only the rotation is performed at 2000 to 4000 rpm for 10 to 20 seconds. Since the transfer has already been completed so as to cover the entire surface of the wafer, the resist blown off by rotation is minimized. In particular, when the drying step is performed separately from the transfer step and the drying step, a small amount of the resist may be applied to the upper part of the front layer of the transferred resist without any problem, regardless of the wafer size. Since a non-uniform film thickness can be obtained, not only the processing time can be shortened, but also the process can be realized in which the reliability and the throughput are improved at the same time.

In both of the above two coating methods, when the coating is completed, the drip nozzle 14 and the drying nozzle 17 return to the standby position, and the resist coating step is completed. At this point, the transferred wafer 11 has the desired film thickness, and the process proceeds to the heat treatment for curing the resist without needing to perform high-speed spin again.

Next, a sectional view of the stage rotating mechanism of the spin-rotating type coating apparatus shown in FIG. 2 will be described. Way
The c 11 is fixed to a stage 12 thereunder, and is rotated by a spin motor 13. The drip nozzle 14 supplies the resist from the lower end facing the wafer side. One end or the middle point of the straight line formed by the lower end portion is the wafer 1.
1 is set to be on the center point. Resist and N
_The dry gas composed of ₂ or the like moves inside the resist insertion tube 16 and the drying gas insertion tube 19 as shown by arrows in FIG. 2 to perform resist dripping and drying gas blowing through the dripping nozzle 14 and the drying nozzle 17, respectively. .

FIG. 3 shows a drip nozzle 14 according to the present invention.
The coating area of the resist by the drying nozzle 17 and the dripping
It is a perspective view of the wafer which shows the example of a drying area. This figure shows a case where the nozzle is set in accordance with the diameter of the wafer 11, and the nozzle starts rotating from the line ab and shows a state where the nozzle is on the line a'-b '. ing.
A hatched portion indicating the application area 31 indicates a portion where the drying gas is completely blown out by the drying nozzle 17 after the resist is dropped by the dropping nozzle 14. Wafer 11
Is rotated clockwise, so that a resist-coated portion is formed on the left side of the nozzle as viewed from the side. If the left and right positional relationship between the dripping nozzle 14 and the drying nozzle 17 is reversed, the wafer may be set to rotate counterclockwise. In addition, the dripping nozzle 14 and the drying nozzle 17 are present above the double-hatched portion indicating the dripping / drying area 32.

FIG. 4 shows a perspective view of the drip nozzle 14 and the drying nozzle 17 according to the present invention. The dotted lines depicted in the form of perspective inside the nozzle of each, respectively, illustrate a groove 41b for performing balloon of the drying gas consisting of grooves 41a and N ₂ or the like to perform the dropping of the resist. The width 1 of the grooves 41a and 41b is set according to the purpose so as to match the diameter or radius of the wafer to be coated.

FIG. 5 is a sectional view of the dripping nozzle 14 and the drying nozzle 17. The thickness of the groove 41a into which the resist is dropped can be finely adjusted by a resist thickness micro gauge or the like. On the right side is a drop nozzle 1 for resist
4, and a drying nozzle 17 for a drying gas is set on the left side. In the case as shown in FIG. 5, if the front side of the drawing is the outer shell side of the wafer 11, the wafer 11 rotates clockwise, so that it is transferred and applied to the left side as shown in FIG. Becomes

As described above, according to the present invention, the resist can be prevented from being shaken off by spin rotation, and the amount of resist transferred to the wafer 11 can be minimized. The amount of dripping can be reduced as compared with the apparatus.

Further, since a dropping nozzle is used which is uniformly stretched in the radial direction of the wafer in advance, a desired film thickness can be obtained from the beginning, and then immediately dried, so that a wet state is maintained for a long time. The drying unevenness due to the flow of the resist is eliminated, and the problematic uniformity of the film thickness is also improved.
Further, since the coating is completed in a rotation time of about one or half rotation of the wafer, the throughput can be improved.

[0026]

According to the present invention, it is possible to provide a resist coating and an apparatus for realizing the reduction of the amount of resist used and the improvement of the throughput.

[Brief description of the drawings]

FIG. 1 is a perspective view of one embodiment of a spin rotation type coating apparatus according to the present invention,

FIG. 2 is a sectional view of one embodiment of a spin-rotation type coating apparatus according to the present invention;

FIG. 3 is a perspective view showing a coating area and a dripping / drying area in the spin rotation type coating apparatus according to the present invention;

FIG. 4 is a perspective view of a dripping nozzle and a drying nozzle in one embodiment of a spin-rotation type coating apparatus according to the present invention;

FIG. 5 is a cross-sectional view of a dripping nozzle and a drying nozzle in one embodiment of the spin-rotary coating device according to the present invention;

FIG. 6 is a perspective view showing a conventional spin rotation type coating apparatus.

[Explanation of symbols]

 Reference Signs List 11 wafer 12 stage 13 spin motor 14 dripping nozzle 15 dripping nozzle drive mechanism 16 resist insertion tube 17 drying nozzle 18 drying nozzle drive mechanism 19 drying gas insertion tube

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroshi Uchida 25-1, Ekimae Honcho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture In-house Examiner, Toshiba Microelectronics Corporation Tsutomu Iwamoto (56) References JP-A-3-267169 (JP, A JP-A-4-278517 (JP, A) JP-A-5-13320 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/027

Claims (4)

(57) [Claims] 1. A stage for mounting a wafer, a rotation mechanism for rotating the stage, a drip nozzle for dropping a resist on the wafer, and a drying nozzle for blowing a drying gas of the resist on the wafer. The drip port of the drip nozzle and the outlet of the drying nozzle are each formed in a groove shape that is long in the diameter direction of the wafer, and a part of the groove of the drip nozzle is close to the wafer when the wafer is closed. A resist coating apparatus that performs resist coating by being positioned on a center point of the resist coating apparatus. 2. The method according to claim 1, wherein the dropping port and the blowing port have a radius equal to or larger than a radius of a wafer, and one end of a groove of the dropping port is located on a center point of the wafer, and the wafer is rotated once or 2. The resist coating apparatus according to claim 1, wherein the resist is transferred and dried by rotating the resist further. 3. The dripping port and the blow-out port have a diameter equal to or larger than the diameter of a wafer, and a midpoint of a groove of the dripping port is located on a center point of the wafer. 2. The resist coating apparatus according to claim 1, wherein the resist is transferred and dried by rotating the resist two or more times. 4. An inert gas is used as the drying gas,
The wafer is rotated by the rotating mechanism to drop and transfer the resist through the dropping port, and thereafter, the solvent in the resist is volatilized and dried by a dry gas from the drying nozzle, thereby forming a predetermined film. 2. The resist coating apparatus according to claim 1, wherein the thickness is obtained.