JPS5898164A - Method and device for attaching thin layer of coating material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The need to apply extremely thin layers of coating materials to a substrate, or workpiece, arises in a variety of situations. For example, the preparation of thin coatings is an essential step in the manufacture of miniature semiconductor electronic circuits, commonly known as "chips."

In fact, it is necessary to create very thin coatings, for example less than 1 micron thick. Furthermore, in the manufacture of semiconductor products, it is often necessary to cut away portions of the surface of a semiconductor substrate to form electrical circuits having desired characteristics. In that case, it is necessary to create a thin layer of photocurable resin material on the semiconductor, and even if the surface to be coated with the layer of material is uneven, the layer of material has a uniform thickness. This is extremely important.

Another problem among many specific problems is, for example, what is known as edge bulge. This is due to the uneven thickness of the coating material that occurs when the spin coating method is used. Yet another problem is that of fouling of the liquid layer.

Accordingly, the present invention provides a dual-speed continuous method for applying a thin, uniform coating of liquid material and drying the coating, and suitable equipment for carrying out the method.

Thus, in accordance with the present invention: positioning the substrate so that one side of the substrate faces upwardly and in a generally horizontal position; dissolving an amount of the selected coating material in a solvent to form a liquid; positioning a substrate in a coating chamber; adding vaporous coating material solvent to the atmosphere of the coating chamber; depositing a quantity of liquid on the surface of the substrate; Spreading the liquid radially over one side of the substrate by rapidly rotating the substrate to form a coating thereon; transferring the coated substrate directly from the coating chamber to a drying chamber; and then drying the coated substrate until the coating is dry. A method for depositing a thin layer of a selected coating material on one side of a generally planar substrate is provided, the method comprising the step of heating the substrate to a single force in a drying chamber.

The present invention further provides a device for forming a coating chamber; a turntable disposed in the coating chamber and configured to receive and support the substrate; and a turntable for applying a liquid coating to the surface of the substrate. a device for adding evaporated solvent of the liquid coating material to the inside of the coating chamber; rotating the turntable to spread the liquid coating material in the radial direction over the surface of the substrate; do,
an apparatus for forming a thin layer thereon; an apparatus for forming a drying chamber; said without actually disturbing the solvent pressure in the pre-SL cocoing chamber! ii - a device for transferring the roots from said coating chamber to said drying chamber; associated with said drying chamber; and a device for heating the coated roots until said thin coating layer is dry; An apparatus is provided for depositing a thin layer of a selected coating material onto a generally flat substrate in a high speed continuous manner.

According to the invention, vapor of a solvent of a selected coating material is added to the atmosphere surrounding the substrate, a quantity of the selected coating material is applied to the substrate in liquid form, and the substrate is then rotated.
That is, it is rotated to move the liquid coating material radially outward and spread over the relevant surface of the substrate. The vaporous solvent atmosphere causes the coating material to remain in a liquid state, and the rotating or swirling action produces a thin coating with uniform N content throughout, even when there is significant non-uniformity in the surface forming the coating. Create.

According to a preferred embodiment of the invention, an apparatus with separate coating Y and drying chamber is provided. A vaporous solvent atmosphere is added to the coating chamber, but not to the drying chamber. A carrier or base is provided for the substrate to be coated. The substrate and its carrier are first placed in a coating chamber, where the coating is applied, and then transported to a drying chamber, where the coating is dried.

As another feature of the invention, an apparatus is provided for transporting a substrate and its carrier between two chambers without exposure to the outside atmosphere. In this way, the substrate and its coating are protected from contamination during the entire coating and drying process.

As another feature of the invention, a reservoir for liquid coating material is provided in communication with the bottom of the coating chamber. The reservoir is therefore in contact with the vaporous solvent atmosphere of the coating chamber. Therefore, while the substrate and its carrier are rotating, i.e. pivoting, the excess coating material flowing off the substrate remains in liquid form and is received by said reservoir device without any drying effect or other damage and is therefore completely can be reused.

Yet another feature of the invention is that it is easily adapted to continuous, high speed manufacturing processes. The apparatus shown here includes provision for such a method. In particular, a number of drying chambers are provided to operate in conjunction with one coating machine having a coating chamber. Each drying chamber is loaded with a carrier carrying a substrate to be coated, and the drying chamber is brought into communication with the coating chamber of the coating machine; the carrier and substrate are transferred from the drying chamber to the coating chamber. a coating operation is performed on the substrate; the carrier and the newly coated substrate are returned to the drying chamber; the drying operation begins and continues while the drying chamber is being moved away from the coating chamber; Another drying chamber carrying another carrier with the substrate to be coated is then brought into communication with the coating chamber and the whole process is repeated.

The high speed and efficiency of this method is due to the fact that each carrier along with the substrate it carries can be transported between the two chambers without significantly compromising the vaporous solvent atmosphere in the coating chamber. achieved.

Therefore, no time is lost in re-creating the vaporous atmosphere.

Reference is now made to FIG. 1, which generally shows an apparatus for carrying out the continuous manufacturing method according to the invention. An operator 10 is seated on a table 11 on which a rotating turret assembly 20 is positioned.
sit down. The turret 20Fi is supported by a vertical shaft 21 and has four horizontal arms 22, 23, 24, 25. The arms are located in a common plane at the addition of the shaft W
has been done. There is a 90 degree thickness between adjacent arms.

The turret heads 22a, 23a, 24δ, 25a are located at the ends of the corresponding turret arms. It's faded.

K, turret arm 25°222 as shown in Figure 1
It is located above the 23-piece work table 11,
The cheeseel does not extend below the location of the turret arm 24. Instead, a coating machine 50 is provided below the turret head 24a.

A substrate base or carrier 40, shown in FIGS. 4, 5, 2 and 6, is used to support the substrate S to be coated. A carrier 40 loaded with a series of substrates is sent to the operator 10.

A valley carrier, or substrate base, is then loaded onto the empty turret head just to the right of where the operator 10 is wearing. As shown in FIG. 1, 1 is the turret head holder 23a in this case.

The position of the turret head in FIG. 1 is considered the loading section. After the substrates are loaded on this turret head, the turret is rotated by 90 degrees so that the next newly loaded turret head arrives at the coating machine 50. At the same time, the carrier, that is, the substrate base 40 coated in the coating machine and then discharged from the coating machine, is conveyed by the turret with an angular movement of 90 degrees. Next, the cooling compartment location, which is the location of turret head 25- in FIG. 1, is reached.

As the turret then rotates, the carriers or substrate bases in the cooling compartment 2 are moved to the unloading compartment to the left of the operator 10 where they are unloaded from the turret head. In FIG. 1, the loading and unloading section is the turret head 22a.
is occupied by

Reference is now made to FIG. 2, which shows coating machine 50. The main frame 51, supported by the legs 51a, is in the form of a cylindrical tank as a whole, with a horizontal top wall 52 and a horizontal wall 52 slightly below the top wall. It has a partition wall 53, another horizontal partition wall 54 located further down, and a horizontal bottom wall 55. It has 53 horizontal partition walls and a central opening 57 surrounded by a short cylindrical wall 58 extending from the nuclide 53 in the -F direction. Solvent bath 60
is arranged on the upper surface of the horizontal partition wall 53 and surrounds the circular wall 58. Since the solvent bath 60 is continuously disposed inside the housing 51, the space between the top wall 52 and the horizontal partition wall 54 is filled with vaporized solvent. Specifically, the steam within the apparatus is at a saturation pressure level, as explained below. The saturated steam acts like raindrops, continuously collecting dirt and other contaminant particles within the closed atmosphere of the housing, thereby preventing contamination of the substrate and its coating.

An important element of the coating machine is the turntable 70, which is supported by an elongated shaft 71 below the table Vi. In FIG. 2, the turntable is shown in its lowered position, used for coating operations. The turntable is lifted into its upper position as shown in FIG. 5 when the carrier 40 is placed into one of the turret heads and is received from or returned to the drying chamber.

A tank 80 containing a liquid photocurable resin material 81 is a second tank.
As shown in the figure, it is located above the housing 51 and on the left side. A valve 82 controls the overall flow of the photoresist material from tank 80 via piping 83 to distribution arm or tube 84 . The lateral position of the distribution arm 84 is controlled by a retractable arm 85, which in turn is controlled by a lensoid 86. In particular, when the coating operation is started, the lower end of the dispensing arm 84, ie the dispensing opening, is positioned over the radial center of the turntable 70, and therefore also between the carrier 40 and the substrate S, as shown in FIG. located on the radial center of Valve 82 is then opened for a short period of time sufficient to allow the required amount of photoresist material to flow downwardly, depositing the material on the radial center of substrate S. Once this operation is completed, the lensoid 86 is actuated, causing the dispensing arm 84 via the arm 85 to rotate in a horizontal plane and thus move completely away from the central opening 57 of the septum 53.

A generally conical collection bag [90] is located inside the Uzong 51 and below the turntable 70. As shown in FIG.
It is welded to the inner wall of the tank, and is sloped at an angle such that the lowest point is on the right side of the tank, as shown in Figure 2.

Excess liquid photoresist material 91 is collected at this point and flows outwardly through a permanently attached tube 92 into a bottle or container 93. The container 93 acts as a reservoir for excess photocurable resin material. This extra material can therefore be reused.

The central opening 57 of the bulkhead 53 is sized so that the turntable 70 can easily pass therethrough. Although not shown in detail, the passing movement of the turntable may receive a new carrier with a substrate requiring coating or return a newly coated substrate with its supporting carrier to the turret from which the substrate was sent. 5 Occurs every time the turntable rises.

- Disposed within the housing 51 and below the bulkhead 54 is a rotary drive assembly generally designated 100;
The assembly is surrounded by a shaft 71 for the turntable to provide rotational drive. The rotary drive may employ any conventional construction, and therefore there is no need to describe the specific details of the rotary drive mechanism shown in this figure.

A vertical drive mechanism 110 is located through the entire bottom wall 55 of the turntable shaft 71 and extends to the underside of the housing.

The lower end of the turntable shaft 71 is carried by a thrust bearing on the thrust plate 111, which allows the shaft to rotate relative to the plate. The plate 111 can be selectively raised or lowered by a vertical drive, the main element of which is a pneumatic actuator f.
It is 112. The vertical drive may employ any suitable mechanism for this purpose, so there is no need here again to explain the specific details of Part 6. Elongated keys 72 supported by shaft 71 are engaged with the rotary drive at the turntable's up, h-, and down plane positions 2 .

The carrier or substrate base 40 is fixed in its desired position by vacuum. Two separate vacuum systems are used, one in the coating machine 50 and the other in the turret 20. Generally, a vacuum system inside the coating machine moves the carrier 40 to the turntable 7 within the coating machine.
Used to hold above 0. A vacuum system in the turret is used to hold the carrier within its associated turret head. When the carrier is transferred from the drying chamber (turret head) to the coating chamber or vice versa, it is necessary to release one vacuum device and activate the other. Although this technology itself is not new,
It will be readily appreciated that it is useful to explain how this is implemented in the apparatus of the present invention.

As shown in FIG.
1 and a rotatable coupling 122, the turntable shaft 71 is connected to the lower end of the hollow turntable shaft 71 in its length. Thus, as best seen in FIGS. 6 and 7, the internal passageway T5 is connected to the shaft 71.
It extends to the upper end and opens into a plurality of radially extending grooves 77 formed on the upper surface of the turn cheagle 70 . The radial length of the groove is significantly smaller than the radial length of the substrate base or carrier 40, as shown in FIGS. 42 and 5.

Thus, when the substrate base or carrier 40 is supported on the turntable TO, its flat underside completely covers the upper end of the vacuum passage 75 and surrounds the upper side of all radial grooves 77. . A vacuum sealing ring 78 is attached to the groove 7.
The turntable 70 is supported by a circumferential groove on the upper surface of the turntable 70, which is located a short distance outside the radially outer end of the turntable 70. The passageway 75 and the groove 77k; I try not to.

The turntable 70 also includes a sealing ring 79 located in a circumferential groove near the outer periphery of the turntable 70 . -・Uzong 51
0 top wall 52 has its instep connected to the substrate base, that is, the carrier 4.
It has a central opening 52a large enough to allow 0 to pass through. See Figures 2 and 5. FIG. 5 shows the relative relationships among the various members of the coating machine when the carrier is completely transferred between the chambers. The outer sealing ring 79 on the top surface of the turntable 70 and the common wall 5 of the ussing
2 prevents solvent vapor from escaping from the coating chamber to the drying chamber.

The turret arm 24 shown in FIGS. 2 and 5 is hollow and includes vacuum piping therein. Turret head 24a, shown in FIGS. 2 and 5, is adapted to receive carrier 40 and retain it by vacuum suction. As shown in FIG. 6, the turret head has on its circumferential lower surface 120 inner and outer rings 121, 122 similar to those on the turntable. like,
An outer sealing ring 122 engages the top surface of the housing top wall 52 to prevent outside air from entering the interior of the device. Inner sealing ring 121 engages the flat top surface of kitria 40 and maintains the vacuum suction necessary to support the carrier.

As can probably be seen best from FIG. 4, the carrier or substrate base 40 is generally trapezoidal but arranged with a stepped circumferential surface.

Thus, the first or outer planar surface 41 is cut into sealing engagement with the sealing ring 121 of the turret head. Although not specified in detail, the second, slightly higher step is fitted with a flat metal ring 42. A flat ring 43 of smaller diameter is permanently attached to the sixth, higher step. The central part of the carrier 40 is raised further and has a heating pad 44 which is flat over its entire surface, as best seen in FIGS. 6 and 4.
It is equipped with The connection 42a between the flat heating pad 44 and the outer contact ring 42 is provided through an inner groove or recess in the upper surface of the carrier below the inner contact ring 43. There is also a connection 43a between the inner contact ring 43 and the heating pad 44.
is being done.

The turret head 7, 4a (cl:' includes internal contacts 125 mounted on d', which are connected to the circulation circuit wiring 126).

Also included is a spring-loaded external contact 127 connected to the twisted electrical circuit wiring 128. When the carrier 40 is fully received inside the turret head, the spring contacts 125, 177
(d) Contact the electrical contacts 43 and 42 of the external (llll) respectively. For an appropriate time, the electric wires 126 and 128 are connected to the electrical contacts (
ji is supplied, passing a current through the heating pad 44 to provide a heating effect on the top surface of the carrier 40.

Substrate S is typically a very thin wafer of semiconductor material, with N shown exaggerated in the drawings for illustrative purposes. Substrate S is located on the flat top surface of heating pad 44. See Figure 6. The substrate is held in place by a set of six bins, or stops P, which are spaced 120 degrees apart around the circumference. A sharp vertical edge that doubles with the lateral edge surface of the substrate, but the bottle does not pass all the way over the top surface of the substrate.
In the figure and in FIG. 6, 7T appears to be shown with fnP passing over the top surface of the substrate, but in reality this is not the case as clearly seen in FIG.

In this way, the substrate can be placed on the carrier 40, which transports the substrate through the coating and drying process. The fully coated substrate can then be removed from the carrier, and the carrier is ready to receive another substrate to repeat the process.

During the operation of the manufacturing machine shown in FIG. 1, the turret 20
are in the same direction, but sequentially rotate one step at a time. The turret is also raised and lowered as it rotates through each stage. The turret lifts the carrier 40 out of the opening 52- and provides space above the top wall 52 of the chamber. When the turret is raised, the sealing relationship between the turret head and the coating machine is established by sealing ring 122.
Vacuum sealing with the carrier 40 is effective at the nozzle 121, although it is no longer present at the nozzle 121. At this time, the upper side of the turntable 70 is connected to the wall 52! Stay in the river,
Maintains the bath salt atmosphere inside the housing.

When a new carrier with a substrate to be coated is brought into position, the turret is lowered and the associated turret head engages the wall 52. The vacuum suction power supplied from the turret arm is cut off to release the carrier from the turret head. Vacuum is supplied to the turntable from a vacuum generator 120. The turntable then descends to its lower position.

As shown in FIG. 2, the next step is to rotate the dispensing arm 84 to its operative position. Then, the valve 32 is activated to completely release a certain amount of the photocurable resin onto the surface of the substrate S. Next, the rotation drive device 100 is operated to rotate the turntable. The turntable, which is used to coat semiconductor wafers, is rotated for 1 minute at a speed of about 3.0.0 rpm. Next, the concave rolling drive device is turned off.

Distribution arm 84, on the other hand, has already been moved.

The turntable is now raised until it engages the upper wall 52 of the uzong, as shown in FIG. A limited amount of solvent vapor is then trapped within the drying chamber. At this time,
Electrical circuits 126 and 128 are energized to heat the substrate and begin drying the coating. Vacuum supply to the turret head is resumed. The vacuum supply to the turntable is cut off. The turret is now raised and carries the carrier 40 and the coated substrate 8. The drying operation is continued for a period of time after the carrier is removed from the coating machine.

The time required to load the carrier into the coating machine, coat the substrate, and remove the entire carrier from the coating machine with the coated substrate is on the order of two minutes. Thus, the machine is capable of coating a large number of substrates per hour in a continuous manner. If it is desired to extend the drying time, the turret can be equipped with more arms.4 This results in the drying time of each substrate's coating being many times the time that the substrate actually spends in the coating machine.

Although the present invention has been described in considerable detail in order to satisfy patent law by fully disclosing at least one embodiment thereof, the detailed description is limited to the broad features of the invention, certain principles, and certain patent claims. It is not intended to limit the scope in any way.

[Brief explanation of the drawing]

Figure 1 is the top 1n1 diagram of the continuous manufacturing machine according to the present invention;
The figure is a side sectional view taken along line 2--2 in FIG. 1, showing the coating P and the drying device; FIG. 4 is a side cross-sectional view of the turntable assembly and substrate base in the downward or coating position; FIG. 5 is a side view of the substrate base during vertical movement between the coating ♀ and the drying chamber. FIG. 6 is a drawing similar to FIG. 5, but showing the entire board board after it has been lifted from the turntable in the drying chamber; FIG. 7 is a drawing along the lines of FIG. 6. 7-7 is a cutaway top view of the turntable assembly; FIG. In the figure, 2, 2, 23, 24, 25...Turret arm, 22a, 23a, 24a, 25a...Arm head, 40...Carrier, 44...Heating pad, 50
... Coding machine, 51 ... Main frame, 70.
... Turntable, 80 ... Tank, 84 ... Distribution arm, 90 ... Reservoir device, 100 ... Rotation drive assembly, 110 ... Drive #1 mechanism, 120 ... Vacuum generation ° Device, 126.128...Wiring, S...Substrate,
P...stop member. Representatives: Asamura and 4 people

Claims (1)

Claims: (1) a method for depositing a thin layer of a selected coating material on one side of a generally planar substrate, the second side of the substrate being in an upwardly facing, generally horizontal position; arranging a substrate; dissolving a quantity of a selected coating material in a solvent to form a liquid; positioning the substrate in a coating chamber; adding a coating solvent in vapor form to the atmosphere of the coating chamber; depositing a liquid on one side of the substrate; rapidly rotating the substrate about a vertical axis passing through the substrate to spread the liquid radially over one side of the substrate; forming a coating; and then transporting the coated substrate directly from the coating chamber with the vapor solvent to a drying chamber and heating the substrate in the drying chamber until the coating is dry. method of applying a thin layer of coated coating material. 2. The method according to claim 1, wherein the coating formed on the surface of the substrate has a thin, generally uniform thickness both on and between the cut surface portions. 3. A method of depositing a thin layer of a selected coating material, characterized in that the coated substrate is transported to a drying chamber. (4) Forming the coating chamber. (4) Forming the coating chamber. an apparatus; a turntable disposed within the coating chamber and configured to receive and support a substrate thereon; an apparatus for depositing a liquid coating material on the surface of the substrate; an apparatus within the coating chamber; a device for adding a vaporous solvent for the liquid coating material; a device for rotationally driving the turntable to spread the liquid coating f; A′ over the surface of the substrate in a radial direction; a device for forming a drying chamber; and; t41-1 a device for transporting the substrate from the coating chamber to the drying chamber without substantially disturbing the solvent order within the TTF coating chamber; Apparatus for depositing a thin layer of a selected coating material on a generally flat substrate by a high-speed, continuous method characterized in that the apparatus comprises in combination a device for heating the coated substrate. In order to collect excess liquid that runs off the surface of the substrate in the device described in Section 4,
Apparatus for depositing a thin layer of a selected coating material, characterized in that it generally includes a liquid reservoir associated with the coating chamber and exposed to an atmosphere containing a vaporous solvent. (6) The apparatus according to claim 5 includes a carrier that supports a substrate, and the conveying device conveys the carrier on which the substrate is supported from the coating chamber to the drying chamber. Apparatus for depositing a thin layer of a selected coating material, characterized in that: 7. An apparatus according to claim 6, characterized in that the drying chamber includes a device R for transmitting an electric current through the carrier to heat the substrate. A device that makes it stick.