JP3240383B2 - Heat treatment equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the heating/cooling processing time of a planar body to be treated, to uniformize the in-plane temperature distribution of the body under treatment and improve the manufacture yield. SOLUTION: A heat treatment part 100 having a heating unit 21A heating a semiconductor wafer W to a prescribed temperature and a cooling unit 11A for cooling it to the prescribed temperature, a resist processing part having at least either one of a resist applying device 12 applying resist solution to the semiconductor wafer W and a developing device 8 executing a developing processing thereon, a main arm 5 for transferring the semiconductor wafer W between the heat treatment part 100 and the resist processing part, and a sub-arm 90 for transferring the semiconductor wafer W between the prescribed units in the heat treatment part. A cooling temperature adjusting body 40 for cooling the semiconductor wafer W to a prescribed temperature is installed in the sub-arm 90.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment apparatus that heats a workpiece and then cools the workpiece to a predetermined temperature to adjust the temperature of the workpiece.

[0002]

2. Description of the Related Art Generally, in a semiconductor device manufacturing process, a circuit pattern is reduced on a surface of an object to be processed such as a semiconductor wafer (hereinafter, referred to as a wafer) by using a photolithography technique and transferred to a photoresist. Is developed.

In this photolithography process,
First, the surface of the wafer is cleaned to remove dust and dirt on the unprocessed wafer, and thereafter, heat-drying is performed. Immediately after cooling, the wafer is conveyed to a resist coating apparatus, and a resist film is coated and formed on the wafer surface by, for example, a spin coating method. Thereafter, the wafer is transferred to a heating device and subjected to a pre-bake process at a predetermined temperature (around 80 ° C.) for a predetermined time to evaporate the solvent from the resist film. After that, the substrate is cooled to, for example, room temperature (23 ° C.), transported to an exposure device, and subjected to an exposure process. The wafer after the exposure processing is transferred to a heating device and subjected to a baking process (pre-development baking process) at a predetermined temperature for a predetermined time. The wafer after the completion of the baking process is transferred to a developing device, where the wafer is subjected to a developing process, and then transferred again to a heating device, and is post-baked at a predetermined temperature (50 to 180 ° C.) for a predetermined time (after development). (Bake treatment), and a developer or the like remaining in the photoresist after development is heated and evaporated. Thereafter, the wafer is transferred to a cooling device, cooled to room temperature (23 ° C.), that is, the temperature is adjusted, and then transferred to the next step.

As described above, in the photolithography process, the wafer to be processed is heated to a predetermined temperature before and after the resist coating and before and after the development process, and is cooled to room temperature before being transferred to the subsequent process. Since it is necessary to perform a treatment, heat treatment of heating and cooling is an important step.

In a conventional photolithography process of this type, a heating device and a cooling device are arranged at different positions, and the wafer after the heat treatment is transferred to the cooling device by a transfer means such as a robot. At times, the temperature of the wafer changes due to the effects of self-radiation and cooling by the surrounding airflow, and the in-plane temperature distribution becomes non-uniform, resulting in non-uniform resist film thickness, uneven development, etc., resulting in a low product yield. There was the problem of causing a decline.

Japanese Patent Application Laid-Open No. 6-2920 discloses a means for preventing the influence of self-radiation during wafer transfer and cooling by airflow.
The technology described in Japanese Patent Publication No. 3 is known. This Japanese Unexamined Patent Publication No.
The technology described in Japanese Patent No. 29203 discloses a heater installed in an upper part in a bake unit and heating the wafer from above in a non-contact manner, a cooling plate installed in a lower part in the bake unit and cooling the wafer, a bake unit The heat treatment apparatus includes an elevating pin that moves up and down while horizontally supporting a wafer therein, and an adiabatic shutter that is provided between the heater and the cooling plate and divides a sealed space in the bake unit into two vertically.

[0007]

However, in the conventional heat treatment apparatus of this type, the wafer is heated by a heater installed at a non-contact position above the wafer, so that the wafer is heated at a high temperature of, for example, 180 ° C. There is a problem that it takes a lot of time to heat to a temperature and a lot of heat energy, and it is difficult to make the in-plane temperature distribution of the wafer uniform. Also,
Since the heater and the cooling plate are installed in the same unit, there is a problem that both the heater and the cooling plate are thermally affected. This problem is solved when the adiabatic shutter is closed, but when the adiabatic shutter is open,
It is inevitable that both the heater and the cooling plate will be adversely affected by heat. Further, since the heat insulating shutter is pulled out of the state housed in the shutter winding device and moves into the bake unit, particles are generated in a sliding portion between the heat insulating shutter and the bake unit, and the particles adhere to the wafer. However, there is a problem that the product yield is reduced.

In particular, in the case of forming a chemically amplified resist film, after performing a pre-development bake treatment after the exposure treatment,
If the cooling process is not performed within a short time, there is a problem that the amplification reaction proceeds and adversely affects the line width formed on the wafer surface. Furthermore, after performing the above-mentioned baking process,
If the time until the cooling process is not constant, there is a problem that the line width varies for each wafer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and aims to shorten the time required for heating and cooling the object to be processed, to make the in-plane temperature distribution of the object to be uniform, and to improve the product yield. It is an object of the present invention to provide a heat treatment apparatus.

[0010]

According to a first aspect of the present invention, there is provided a heat treatment apparatus having a heating unit for heating a plate-shaped object to a predetermined temperature and a cooling unit for cooling the plate-like object to a predetermined temperature. A heat treatment section, a resist processing section having at least one of a coating unit for applying a resist liquid to the object to be processed and a development unit for performing development processing, and at least the heat treatment section and the resist processing for the object to be processed. A first transport unit that transports the object to be processed, and a second transport unit that transports the object to be processed only between predetermined units in the heat treatment unit, wherein the second transport unit includes: A cooling temperature adjusting function for cooling the object to be processed to a predetermined temperature is provided.

In this case, the object to be processed is transported while holding the peripheral portion of the object to be processed by the first transport means, and the front and back surfaces of the object to be processed are covered by the second transport means. It is more preferable to convey the paper (claim 2).

According to the present invention, the object to be processed is transported only between predetermined units in the heat treatment section separately from the first transport means for transporting the plate-like object to be processed between the heat treatment section and the resist processing section. By providing the second transfer means, the object to be processed which has been subjected to the heat treatment by the heating unit is received by the second transfer means having a cooling temperature adjusting function for cooling the object to be processed to a predetermined temperature, and is transferred to the cooling unit. Can be handed over.
Therefore, the object to be processed which has been subjected to the heat treatment can be quickly conveyed to the cooling unit, and the thermal effect of the object to be processed can be reduced as much as possible, and the throughput can be improved. At this time, since the second transfer means has a cooling temperature adjusting function, a cooling process can be performed during the transfer of the object to be processed, and the throughput can be further improved.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. Here, the case where the heat treatment apparatus according to the present invention is incorporated in a semiconductor wafer coating / developing processing system will be described.

As shown in FIG. 1, the semiconductor wafer coating / developing processing system 1 includes a plurality of cassettes 2 accommodating, for example, a large number of semiconductor wafers W (hereinafter, referred to as wafers W) at one end thereof. It has a carrier station 3 which can be individually mounted, and an auxiliary arm 4 for carrying in / out a wafer W and positioning the wafer W is provided at the center of the carrier station 3. In addition, a process station 6 is arranged on the side of the carrier station 3 side of the coating / developing processing system 1. Further, at a central portion thereof, it is provided so as to be movable in the length direction (X direction), a direction orthogonal thereto (Y direction) and a vertical direction (Z direction), and rotatable (θ).
A substantially horseshoe-shaped main arm 5 as a first transfer means for transferring the wafer W from the auxiliary arm 4 is provided. On one side of a transfer path of the main arm 5, a brush scrubber 7 and a high-pressure jet cleaning are provided. Machine 7A, heating unit 21
A heat treatment section 100 in which A and a cooling unit 11A are stacked is disposed, and two developing devices 8 (developing units) are disposed in parallel on the other side. In this case, three heating units 21A are placed on one cooling unit 11A.
Are arranged to form a heat treatment section 100.

On the other hand, on the side of the process station 6, an adhesion processing apparatus 10 is provided as another process station 6A via a connection unit 9, for example, for applying a hydrophobic treatment to a wafer W before applying a photoresist to the wafer W. Is provided. On the side of the adhesion device 10, two rows of heat treatment units 100 in which three heating units 21A are stacked on one cooling unit 11A are arranged.

Two resist coating units 12 (coating units) for coating a photoresist liquid on the wafer W are arranged on the opposite side of the heat treatment unit 100 and the adhesion processing unit 10 across the transfer path of the main arm 5. Has been established. The resist coating unit 12 and the developing device 8 constitute a resist processing unit. Note that the interface unit 1 is provided on the side of these resist coating devices 12.
An exposure device 14 and the like for exposing a predetermined fine pattern to the resist film via the reference numeral 3 are provided.

On the opposite side of the main arm 5 of the heat treatment unit 100, the wafer W is heated by the heating unit 21A so as to cover the upper and lower surfaces (front and back) of the wafer W, and is received by the cooling unit 11A. A sub arm 90 as a second transfer means for transferring is provided so as to be movable in the X, Y, and Z directions and rotatable (θ). This sub arm 90
Is provided with a cooling temperature adjustment function. That is, the sub-arm 90 is provided with a cooling temperature adjusting body 40 as a cooling temperature adjusting means described later.

In this case, the sub arm 90 is moved in the X direction along a transport path (not shown), moved in the Z direction by, for example, a ball screw mechanism 91, and is heated or cooled by the air unit (not shown). It is configured to be able to move forward and backward (Y direction) with respect to 11A.

As shown in FIG. 2, the heating unit 21A has a housing having a carry-in / out port 21a for the main arm 5 on one side and a carry-out port 21b for the sub arm 90 on the other side. Heating element 23 (heater) as a heating means for mounting wafer W in predetermined temperature at 21c.
Is provided. Further, below the mounting table 24, three support pins 32 that penetrate the mounting table 24 and support the wafer W can move up and down above the mounting table 24 by driving an unillustrated lifting mechanism. Have been. A shutter 26A is provided at each of the loading / unloading port 21a and the loading port 21b so as to be openable and closable. Further, an exhaust port 28a is provided in an upper part of the housing 21c.

The cooling unit 11A has a loading / unloading port 11a for the main arm 5 like the heating unit 21A.
And a mounting table 24 having a cooling medium passage 11d as a cooling means for mounting the wafer W and cooling the wafer W to a predetermined temperature in a housing 11c having a carry-in entrance 11b of the sub arm 90. Further, similarly to the heating unit 21A, the support pin 32A is configured to be able to move up and down above the mounting table 24 by driving of a lifting mechanism (not shown). Note that a shutter 26B is provided at each of the carry-in / carry-out port 11a and the carry-in port 11b so as to be openable and closable.

The cooling temperature adjuster 40 disposed on the sub-arm 90 has an upper and lower surface arranged in a sandwich shape which covers the upper and lower surfaces of the wafer W moved to a position above the mounting table 24 by the support pins 32, that is, the front and rear surfaces. The vertical cross-sectional shape of the cooling piece 41 and the lower cooling piece 42 and the connecting piece 43 connecting one end of the cooling pieces 41 and 42 is formed in a substantially U-shape. By forming the U-shape in this manner, the thickness in the up-down direction can be reduced, and can be supported by the connecting piece 43 in a cantilever manner, which is convenient for movement and can be simplified. Further, a Peltier element 44 as a coolant is embedded in the upper cooling piece 41 or the lower cooling piece 42 or both, and a radiating plate 45 is provided on the back of the Peltier element 44.
The lower surface side of the upper cooling piece 41 and the upper surface side of the lower cooling piece 42 absorb heat by power supply from a power supply (not shown) to lower the temperature, and the wafer W is cooled to a predetermined temperature, for example, room temperature (about 23 ° C.). It is configured to be able to cool.
In addition, instead of the Peltier element 44, as shown in FIG.
A tubular flow path 44A may be built in, and cooling may be performed by circulating constant temperature water, gas or the like cooled to a predetermined temperature.

The cooling temperature adjuster 4 configured as described above
Numeral 0 is connected to a horizontal moving air cylinder 46 via a rod 46 a connected to the connecting piece 43, and the cooling cylinder 46 is driven by the air cylinder 46 so that the cooling temperature adjuster 40 is attached to the wafer W above the mounting table 24. It is configured to be able to move forward and backward. The air cylinder 46 is formed so as to be movable in a vertical direction (Z direction) by a lifting mechanism (not shown). In this case, as shown in FIG. 4, the lower cooling piece 42 of the cooling temperature adjusting body 40 is provided with a slit 47 for avoiding interference with the three support pins 32 and allowing the support pins 32 to advance and retreat. ing. By providing the slits 47 in this manner, the cooling temperature adjuster 40 is moved toward the wafer W moved to a position above the mounting table 24 by the support pins 32, and the upper and lower surfaces (front and back surfaces) of the wafer W are cooled. When the piece 41 and the lower cooling piece 42 are brought close to each other, the mounting table 24 and the wafer W are cut off in a region other than the slit 47, and the cooling temperature of the wafer W can be adjusted in this state. At this time, since the wafer W is thermally isolated from the mounting table 24 by the lower cooling piece 42, there is no possibility that the wafer W is affected by heat from the mounting table 24.

FIG. 5 shows the cooling temperature adjusting member 4 according to the present invention.
FIG. 7 is a schematic sectional view showing a main part of another embodiment of No. 0;

In the embodiment shown in FIG.
This is a case in which, for example, an inert gas cooled at normal temperature or cooled is supplied from the gas supply means toward the wafer W from 0, and the wafer W before cooling temperature adjustment is replaced with an inert gas atmosphere. That is, an unillustrated inert gas such as nitrogen (N) is provided on the lower surface side of the upper cooling piece 41 of the cooling temperature adjuster 40.
2) The N2 gas supply passage 70 connected to the gas supply source is formed, and the N2 gas supply passage 70 is provided with a large number of injection ports 71 at appropriate intervals. Is supplied in the form of a shower toward the wafer W before the cooling temperature is adjusted. The gas supply means is constituted by the N2 gas supply source and the N2 gas supply passage 70 in which the injection port 71 is provided.

In the above-described embodiment, the N2 gas supply passage 70 and the nozzle 7
1. When N2 gas is supplied to the upper surface of wafer W
However, the N2 gas supply passage 70 and the injection port 71 may be similarly provided on the upper surface side of the lower cooling piece 42 to supply the N2 gas also to the lower surface of the wafer W. Also,
Purified air or other inert gas may be supplied instead of N2 gas.

With the above-described configuration, before the temperature of the heated wafer W is adjusted to the cooling temperature, the wafer W
A gas can be supplied to replace the high temperature atmosphere with a low temperature inert gas atmosphere. Therefore, the surface of the wafer W that has been subjected to the heat treatment can be previously cooled and controlled under the same low-temperature atmosphere, so that the in-plane temperature distribution of the wafer W can be made more uniform. Further, the wafer W can be cooled at a high speed by the N2 gas discharge airflow, and the processing time to the target cooling temperature can be shortened.

In the embodiment shown in FIGS. 5 and 6, the other parts are the same as those in the first embodiment, and thus the same parts are denoted by the same reference numerals and description thereof will be omitted.

Next, the operation of the heat treatment apparatus configured as described above will be described. The wafer W subjected to the exposure processing by the exposure device 14 is transferred to the heating unit 21A while the peripheral portion is held by the main arm 5, and is subjected to the heating processing at a predetermined temperature for a predetermined time. After the heat treatment, the support pins 32 are raised and the wafer W is placed on the mounting table 2.
4 is moved upward (separated). At this time, shutter 2
6A is lowered, the carry-out port 21b is opened, and the sub-arm 9
0 (cooling temperature adjusting body 40) is received and retracted so as to cover the upper and lower surfaces (front and rear surfaces) of the wafer W supported by the support pins 32, and then descends to cool the cooling unit 11A.
Is carried into the cooling unit 11A from the open entrance 11b. At the time of this transfer, the wafer W can be cooled during the transfer by energizing the Peltier element 44. The sub arm 90 transfers the wafer W to the support pins 32A protruding above the mounting table 24 of the cooling unit 11A,
Retreat from the cooling unit 11A. Note that the wafer W is cooled after the sub arm 90 (cooling temperature adjusting body 40) receives the wafer W moved above the mounting table 24.
It may be performed.

After the sub arm 90 retreats, the shutter 26A of the cooling unit 11A rises to close the carry-in port 11b, and at the same time, the support pins 32A descend to place the wafer W on the mounting table 32A. In this state, the mounting table 32A
The wafer W is cooled to a predetermined temperature, for example, room temperature (23 ° C.) by the refrigerant flowing through the refrigerant passage 11d embedded in the wafer W.

Therefore, the heated wafer W is
Since the wafer W is immediately transferred to the cooling unit 11A by the sub-arm 90, the wafer W of the heating unit 21A is overheated when the main arm 5 is transferring another wafer W or the timing of receiving the wafer W is delayed for some reason. It can be prevented from being affected by heat such as being in a state. In particular, when a pattern is formed using a chemically amplified resist film, it is preferable in that a line width of the pattern of the wafer W can be prevented from being adversely affected without being uniform and fluctuating.

Other Embodiments 1) In the above embodiment, the case where the heating unit 21A and the cooling unit 11A are vertically stacked and arranged has been described.
1A does not necessarily need to be arranged in the vertical direction, and may be arranged in the horizontal direction. Further, any number of heating units 21A and cooling units 11A can be provided as needed. Further, in the above embodiment, the Peltier element 44 is used as the cooling temperature adjustment function provided in the sub arm 90, but a cooling unit other than the Peltier element 44 may be used.

2) In the above embodiment, the case where the heat treatment apparatus of the present invention is applied to a semiconductor wafer coating / developing processing system has been described. However, heating and cooling temperature control processing of a semiconductor wafer in other processing steps / processing systems. Needless to say, the present invention can also be applied to those that do. Further, the present invention can also be applied to heat treatment of a plate-shaped object such as an LCD substrate and a CD other than a semiconductor wafer.

[0033]

As described above, according to the present invention, the following effects can be obtained.

Apart from the first transport means for transporting the object to be processed between the heat treatment section and the resist processing section, the object to be processed is transported only between predetermined units in the heat treatment section. By providing the second transfer means having a cooling temperature adjustment function for cooling, the heat-treated object can be quickly conveyed to the cooling unit, and the heat influence of the object can be minimized. It is possible to reduce the number and improve the throughput. In addition, since the second transfer means has a cooling temperature adjustment function, it is possible to perform a cooling process during the transfer of the object to be processed, and it is possible to further improve the throughput.

[Brief description of the drawings]

FIG. 1 is a perspective view of a semiconductor wafer coating / developing system to which a heat treatment apparatus according to the present invention is applied.

FIG. 2 is a schematic sectional view showing a main part of the heat treatment apparatus.

FIG. 3 is a schematic cross-sectional view showing one example of a cooling temperature regulator according to the present invention.

FIG. 4 is an exploded perspective view showing a mounting table and a cooling temperature adjusting body according to the present invention.

FIG. 5 is a schematic sectional view showing a main part of another embodiment of the cooling temperature regulator according to the present invention.

FIG. 6 is a schematic side view showing an operation mode of a main part of still another embodiment of the cooling temperature regulator according to the present invention.

[Explanation of symbols]

 Reference Signs List 5 main arm (first transport unit) 8 developing device (developing unit) 11A cooling unit 12 resist coating device (coating unit) 21A heating unit 40 cooling temperature regulator (cooling temperature regulator) 90 sub arm (second transport unit) ) 100 Heat treatment part W Semiconductor wafer (workpiece)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI H01L 21/68 H01L 21/30 565 566 (72) Inventor Koji Harada 2655 Tsukure, Kikuyo-cho, Kikuchi-gun, Kumamoto Prefecture Tokyo Electron Kyushu Stock (56) References JP-A-5-178416 (JP, A) JP-A-4-262552 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21 / 027

Claims (2)

(57) [Claims] 1. A heat treatment section having a heating unit for heating a plate-shaped object to be processed to a predetermined temperature and a cooling unit for cooling to a predetermined temperature, an application unit for applying a resist liquid to the object to be processed, and a developing process. At least one of the developing units
A resist processing unit having at least one, a first transport unit that transports the object to be processed between the heat treatment unit and the resist processing unit, and at least a predetermined unit in the heat treatment unit that transports the object to be processed. A second transfer means for transferring the object, and a cooling temperature adjusting function for cooling the object to be processed to a predetermined temperature in the second transfer means. 2. The heat treatment apparatus according to claim 1, wherein the first transporting means transports the workpiece while holding a peripheral portion of the workpiece, and the second transporting means transports the workpiece. A heat treatment apparatus characterized in that the body is transported so as to cover the front and back surfaces of the body.