JPS62145814A - Photoresist curing device - Google Patents

Abstract

PURPOSE:To approximately double the number of wafers to be processed per hour by separately providing a processing chamber for preliminarily heating and emitting an ultraviolet ray to a photoresist and a baking unit for thereafter baking the photoresist, thereby concurrently processing the photoresist by the both. CONSTITUTION:Preliminarily heating and ultraviolet ray emitting times tp+tu are slightly shorter than or equal to a baking time t in a normal process. Accordingly, the preliminary heating and the ultraviolet ray emitting are achieved in a processing chamber 2, and the baking is executed in a baking room 8 separately provided in parallel with the previous processes. Thus, the photoresist curing process can be performed substantially half a time as compared with a conventional process, thereby increasing by approx. double the number of wafers to be processed per hour.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention is a method of hardening a photoresist coated on a semiconductor wafer after exposure and development and before etching to improve its adhesion to the wafer in the photoetching process of semiconductor device manufacturing. The present invention relates to a photoresist curing device that improves photoresist curing.

[Technical background and problems of the invention]

In so-called post-baking, in which the photoresist pattern formed on the surface of the semiconductor wafer is hardened before etching, the wafer that has been developed is first heated from room temperature TR to a predetermined preheating temperature TP, as shown in FIG. In recent years, a process has begun to be used in which the wafer surface is irradiated with ultraviolet rays at this temperature T to harden the photoresist, and then heated and baked to a predetermined baking temperature T.

This process has the advantage of being able to effectively harden the siding by irradiating it with ultraviolet light before baking, thereby increasing its adhesion to the wafer and improving the viscosity of patterning. Since the device performs all processes from preheating to baking in the same processing chamber, the time required for this process is approximately 1, 1. ．． The sum of 1b (all on the order of minutes) is 1 + 1 + 1b, which has the problem of longer processing time and poor work efficiency compared to the previous resist hardening process that only performed baking. .

[Purpose of the invention]

The present invention has been made in view of the above, and an object of the present invention is to provide a photoresist curing apparatus that can efficiently perform a photoresist curing process consisting of preheating, ultraviolet irradiation, and baking.

[Summary of the invention]

In order to achieve the above object, the present invention includes a preheater and an ultraviolet light source installed in a processing chamber, and a baking device installed separately from the processing chamber to perform baking on a certain wafer. During this time, preliminary heating and ultraviolet ray irradiation can be performed for the next step (1)-8 in parallel.

[Embodiments of the invention] The present invention will be explained below with reference to Examples.

FIGS. 1(a) to 1(e) show various embodiments of the photoresist curing apparatus according to the present invention with different heating methods.

In each of these embodiments, the wafers 1 whose surfaces are coated with photoresist are fed into the processing chamber 2 one by one after exposure and development of the photoresist is completed. Inside the processing chamber 2, there is a hot plate 3 (Fig. 1(a) to (T)) for fixing the wafer 1 in a predetermined position by vacuum suction or the like and heating it to a predetermined preheating temperature (Fig. 2 T). C)) or infrared lamp heaters 4 ((d) and (e)) are installed above these preheaters 3.4 for irradiating ultraviolet rays onto the photoresist on the preheated wafer 1. An ultraviolet lamp 5 is attached.

In addition, the processing chamber 2 is equipped with a vacuum intake pipe 6 for replacing the internal air with nitrogen gas before starting preheating.
and a nitrogen supply pipe 7 are connected.

A wafer 1 that has been processed in the processing chamber 2
is sent to a baking room 8 which is separate from the chamber 2. Inside this baking room 8, the wafer is fixed in a predetermined position by vacuum suction or the like, and the wafer is kept at a predetermined baking temperature (Fig. 2TB).
) Baking hot plate 9 (first
Figure (a).

(d)), infrared lamp heater 10 ((C) of the same figure).

(e)) or an electric heater 11 (FIG. 2(b)) is installed.

Wafer 1 that has been processed in this baking room 8
is sent to the next stage etching processing device (not shown).

In such a configuration, the operation will be explained with reference to FIG. 2. The wafer 1 is fixed at a predetermined position in the processing chamber 2, the air in the chamber 2 is replaced with nitrogen gas, and preheating begins. The wafer 1 is then heated from the chamber IT to the preheating temperature TP. This preheating requires time t, and once this is completed, the ultraviolet lamp 5
is turned on and the photoresist on the wafer 1 is irradiated with ultraviolet rays for a time t. This treatment sufficiently hardens the photoresist.

When the ultraviolet irradiation process is completed, the wafer 1 is pulled out from the processing chamber 2 and sent to the baking room 8, and then the next wafer 1 is sent into the processing chamber 2. In the baking room 8, the wafer 1 is further heated until it reaches the baking temperature T, and is kept at this temperature T for a period of time t.

Only baked. Further, in parallel with this, in the processing chamber 2, the next wafer 1 is preheated for a time t and then irradiated with ultraviolet rays for a time t.

Here, in a normal process, the time required for preheating and ultraviolet irradiation is 1 + 1. is slightly shorter or equal to the baking time tb.

Therefore, preheating and ultraviolet irradiation are performed in the processing chamber 2, and in parallel, a separate baking room 8 is used.
When performing wafer wafer processing in the process, this process can be performed in about half the time of conventional methods, reducing the number of wafers processed per hour. It can be increased by 2 times.

FIGS. 3(a) and 3(b) each show still another embodiment of the present invention.

The basic configuration of the embodiments shown in the same figure is the same as that of Fig. 1 (a), but in the case of the example shown in Fig. 3 (a), the pot plate 3 is connected to its support shaft via a gear A712. The point is that it is horizontally rotated by the motor 13.
In addition, in the case of the same figure (b), the ultraviolet lamp 5 is connected to the gear A7.
It is characterized in that it is horizontally rotated by a motor 13 connected via a motor 12. In both of these embodiments, the bottle 1 to the plate 3 or the UV lamp 5 are prevented from rotating while the UV lamp 5 is turned on.

This eliminates unevenness in the amount of ultraviolet irradiation that occurs due to differences in the order of magnitude on the J-boxes, making it possible to harden the photoresist evenly and uniformly, thereby further increasing the precision of patterning. .

〔Effect of the invention〕

As explained above, according to the present invention, a processing chamber for preheating the photoresist and irradiation with ultraviolet rays and a baking device for baking the photoresist after that are provided separately, and the processing by both can be performed in parallel. As a result, the photoresist curing process can be performed in about half the time of the conventional method, and the number of processes per hour can therefore be doubled.

[Brief explanation of drawings]

1(a) to 1(e) are block diagrams showing various embodiments of the photoresist curing apparatus according to the present invention using different heating methods, and FIG. 2 is a block diagram of the resist curing process to which the present invention is applied. Diagrams showing temperature rise characteristics, Figure 3 (a), (
b) is a block diagram showing further embodiments of the present invention; 1...Semiconductor number 1-c, 2...Processing number, 3
゜9...Hot Bray 1~. 4, 10... Infrared lamp heater, 5... Ultraviolet lamp, 6... Vacuum intake pipe, 7... Nitrogen supply pipe, 8... Baking room,
11... Electric heater, 12... Gear, 13... Motor. Applicant's agent Sato - Male □% Time Figure 2 Figure 1 Figure 3

Claims (1)

[Scope of Claims] An apparatus for curing photoresist coated on the surface of a semiconductor wafer after development and before etching, comprising a preheater for preheating the wafer and irradiation of ultraviolet rays to the preheated photoresist on the wafer. a processing chamber containing an ultraviolet light source for curing photoresist; and a baking device provided separately from this chamber for further heating and baking the wafer that has been processed in the chamber. Device.