JPH0246046Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a light irradiator including an ultraviolet irradiator used for processing photoresist (hereinafter referred to as "resist") applied to a semiconductor wafer. This invention relates to a light irradiator intended to improve the heat resistance and plasma resistance of resist.

[Prior Art] As an example of a light irradiator, an ultraviolet irradiator used for resist processing will be described below.

Regarding conventional processing of resist using ultraviolet irradiation, ultraviolet irradiation is used in processes such as exposing mask patterns on resist coated on semiconductor wafers, and pre-cleaning processes to decompose and clean organic contaminants attached to the resist surface. However, recently,
Application to the baking process, which is one of the resist processing processes, is attracting attention.

The baking process is an intermediate process between the process of forming a resist pattern by resist coating, exposure, and development, and the process of performing ion implantation, plasma etching, etc. using this resist pattern, and is used to bond the resist to the semiconductor substrate. This is a heating process aimed at improving properties and heat resistance. Recently, studies have been conducted on methods and apparatuses for increasing the heat resistance and plasma etching resistance during baking in a shorter time by irradiating the resist with ultraviolet rays before or during the baking process after development.

FIG. 3 is a sectional view showing the main parts of a conventional ultraviolet irradiator, in which 1 is a lamp, 2 is a mirror placed behind the lamp 1, and 3' is a blower 3 for cooling the lamp 1. 4 is a light transmitting plate, 5 is a processing table, and 6 is an entrance/exit for transporting wafers to the processing table 5.

In the apparatus shown in FIG. 2, a wafer coated with a resist, which is transferred from an entrance/exit 6 to a processing table 5 along a wafer transfer line, is subjected to a resist treatment by irradiating ultraviolet rays from a lamp 1.

[Problems that the invention aims to solve] In conventional ultraviolet irradiators, when a resist is irradiated with high-intensity ultraviolet light to speed up processing, gas is generated from inside the resist, and this gas creates bubbles. This causes damage to the resist film, such as occurrence of cracks, deformation of the resist pattern, peeling, rupture, and roughness of the resist film, and causes failure of semiconductor devices.

One of the causes of this gas generation is the rapid photochemical reaction of exposed photosensitive groups in the resist, and the photochemical reaction between the resist and HMDS (hexamethyldisilazane) or antireflective agent applied to the wafer as a pretreatment for resist coating. Possible causes include photochemical reactions of resist additives such as dyes, and photochemical reactions of solvents remaining in the resist.

These photochemical reactions have wavelengths of 300nm to 500nm.
Therefore, in a resist processing apparatus that emits light including these wavelength ranges, the intensity of the light cannot be increased. In other words, there was a problem that high-speed processing could not be performed.

In view of these problems, the present invention provides a light irradiator that can process resists by ultraviolet irradiation at high speed and effectively by preventing the resist from being destroyed by the radiation emitted from the light irradiator. The purpose is to

[Means for solving the problem] In order to achieve this object, this invention includes a shutter, a shutter drive mechanism for driving the shutter, and a light reducing plate having a plurality of perforations disposed in front or behind the shutter. A metal plate and a drive mechanism for this metal plate are provided.

[Function] In this invention, by using a shutter and a metal plate with perforations in combination, when used for resist processing, for example, the exposure wavelength of the resist is effectively reduced, so that gas is generated from the resist. It is possible to provide a degassing step in which the photochemical reaction that occurs proceeds in a controlled manner and gas within the resist is released to the outside of the resist without destroying the resist. Moreover, in that case, following the degassing step, the metal plate is moved,
By setting up a process in which the resist is irradiated with strong ultraviolet rays, the resist will not be destroyed even if it is irradiated with strong ultraviolet rays that simultaneously contain ultraviolet components that are effective in improving the resist's heat resistance and plasma etching resistance, and the wavelength at which the resist is exposed. Fast and effective resist processing can be performed without causing any problems.

[Embodiment] FIG. 1 is a cross-sectional view showing the main structure of a light irradiator according to an embodiment of this invention, in which A is a front view and B is a side view.

In FIGS. 1A and 1B, 10a and 10b are shutters divided into left and right halves, and 11 is a drive mechanism incorporating a reversible motor (not shown).
The two divided shutters 10a and 10b are driven by one motor. Reference numeral 12 denotes a metal plate (hereinafter referred to as a punch panel) which is a light reduction plate having perforations at predetermined intervals. Reference numeral 13 denotes a punch panel drive mechanism having a structure similar to that of the shutter drive mechanism, which incorporates a reversible motor (not shown). 14a,1
4b is the shutter 10 divided into two parts, respectively.
a, 10b, and the upper parts of the frames 14a, 14b are connected to metal fittings 16a, 16b, respectively.
The metal fittings 16a and 16b are connected to a pulley 18 driven by the motor of the shutter drive mechanism 11.
It is fixed above and below a stainless steel wire (belt) 20 wrapped around the wires a, 18b, 18c, and 18d. Similarly, 15 is a frame that supports the punch panel 12, the upper part of this frame 15 is suspended by a metal fitting 17, and this metal fitting 17 is connected to the punch panel drive mechanism 1.
It is fixed to a wire 21 wound around pulleys 19a and 19b driven by a motor No. 3. 22 is the frame 1 of the shutter 10a, 10b which is divided into two parts.
4a and 14b are guide rails that move when driven to open and close, and 23 is a guide rail that moves the frame 15 of the punch panel 12. Further, the same reference numerals as in FIG. 3 indicate the same or corresponding parts.

In the above configuration, the shutter 10
When opening a and 10b, the pulleys 18a to 18d rotate counterclockwise, and the frames 14a and 14b fixed above and below the wire 20 move outward on the guide rail 22, respectively. Also, when closing the shutters 10a and 10b, pulleys 18a to
The shutter 18d rotates clockwise, and the two divided shutters 10a and 10b each have a guide rail 22.
Move the top inward.

Similarly, punch panel 12 is not used (opened).
At this time, the pulleys 19a and 19b rotate counterclockwise, and the frame 15 fixed to the wire 21 via the metal fitting 17 moves on the guide rail 23 toward the right in the drawing. Also, use punch panel 12 (closed)
At this time, rotate the pulleys 19a and 19b clockwise,
The frame 15 is moved to the left in the drawing.

In addition to the above, in order to effectively weaken the intensity of ultraviolet rays, a triple structure consisting of a shutter, a filter, and a punch panel as shown in Fig. 2 can be considered. FIG. 2 is a cross-sectional view showing the main structure of a light irradiator as a second embodiment of this invention, in which A is a front view and B is a side view.

In FIGS. 2A and 2B, 24 is a filter, and this filter 24 is the punch panel 1 serving as a light reduction plate.
2 and the light transmitting plate 4, and is supported by a frame 25. The upper part of the frame 25 is suspended by a metal fitting 26, and the metal fitting 26 is further fixed to a wire 27. 28 is a filter drive mechanism, and wires 2 are connected to pulleys 29a and 29b of the filter drive mechanism 28, which are driven by a reversible motor (not shown).
7 is wound around the wire 27, and the movement of the wire 27 causes the frame 25 to move on the guide rail 30, as in the case of the punch panels 12 of the shutters 10a and 10b. Further, the same reference numerals as in FIGS. 1 and 3 indicate the same or corresponding parts.

In Figure 2, filter 12 is not used (open)
At this time, the pulleys 29a and 29b rotate counterclockwise, and the frame 25, which is fixed via the wire 27 and the metal fittings 26, moves on the guide rail 30 to the right in the drawing. When the filter 25 is used (closed), the pulleys 29a and 29b are rotated clockwise to move the frame 25 to the left in the drawing.

Note that the filter 25 in FIG. 2 is attached to the punch panel 1.
2 and the light transmitting plate 4, but the shutter 10
Even if a filter 25 is provided between a, 10b and the punch panel 12, there is no change in the effect of light irradiation.

Furthermore, the punch panel may have a structure divided into two parts similarly to the shutter. Further, although the shutter, punch panel, and filter have been described as moving independently, it is of course possible to control signals so that these three move in relation to each other.

[Effects of the invention] As explained above, this invention includes at least one lamp with a mirror placed behind it, a shutter placed in front of the lamp, and a shutter drive mechanism that drives the shutter using a control signal. , a metal plate which is a light attenuation plate having a plurality of perforations disposed in front or behind the shutter, a light attenuation plate drive mechanism that drives the metal plate in response to a control signal, and a blower for cooling the lamp. Since the light irradiator is constructed in this way, it has become possible to perform high-speed and effective resist processing.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the main structure of a light irradiator showing one embodiment of this invention, and Fig.
FIG. 3 is a cross-sectional view showing the main structure of a conventional light irradiator. In the figure, 1: lamp, 2: mirror, 3: blower,
4: Light transmission plate, 10a, 10b: Shutter, 1
1: Shutter drive mechanism, 12: Punch panel,
13: Punch panel drive mechanism.

Claims (1)

[Claims for Utility Model Registration] (1) At least one rod-shaped lamp with a mirror placed behind it, a shutter placed in front of this lamp that moves linearly in the longitudinal direction of the lamp, and a control for controlling this shutter. a shutter drive mechanism driven by a signal; a dimming plate made of a metal plate having a plurality of perforations disposed in front or behind the shutter and moving linearly in the longitudinal direction of the lamp; and a dimming plate that is driven by a control signal. This light irradiator includes a light transmitting plate attached to the front side and a light transmitting plate attached to the front side, and a blower for cooling the lamp. A light irradiator characterized by having an airtight structure other than an inlet/outlet for air circulation provided at the rear. (2) The light irradiator according to claim 1, wherein the shutter drive mechanism and the dimming plate drive mechanism are each independently driven by a control signal. (3) The light irradiator according to claim 1, wherein the shutter drive mechanism and the dimming plate drive mechanism are driven in relation to each other.