JPS62111425A - Method for resist treatment - Google Patents

Abstract

PURPOSE:To effect a resist treatment by a irradiation with radiation beams by starting the heating by a wafer treatment table when a predetermined time has passed after the irradiation with radiation beam starts. CONSTITUTION:A shutter 3 is opened under the condition that a semiconductor wafer 5 is in close contact with a wafer treatment table 6, thereby irradiating a resist 4 with radiation beams emitted from a high-pressure mercury lamp 1. After a predetermined time has passed, the wafer treatment table 6 is heated. As a result, a resist pattern becomes not to be damaged even if the heating by the wafer treatment table is added and the temperature increases. After the wafer treatment table 6 is heated for a predetermined time, a heater 10 is turned OFF and simultaneously the shutter is closed to stop the irradiation with radiation beams. Then, water-cooling is performed by flowing a cooling water into cooling holes 11. Thus, the resist treatment is performed effectively.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for processing resist applied to a semiconductor wafer, and in particular, a resist processing method using emitted light from a high-pressure mercury lamp and a processing table having vacuum suction holes. It is about the method.

[Conventional technology]

In a semiconductor device manufacturing process, the formation of a resist pattern is roughly divided into the following steps: resist coating, pre-hake, exposure, development, and post-bake.

After this, using this resist pattern, ion implantation,
Alternatively, a silicon oxide film, a silicon nitride film, an aluminum thin film, etc. previously formed on the surface of the semiconductor wafer may be etched before the resist is applied. After these steps, the resist is removed.

In recent years, with the increasing integration and miniaturization of semiconductor devices, resists with higher resolution have been used, and in this case, the heat resistance of the resists tends to deteriorate. On the other hand, resist deterioration (film peeling, etc.) during etching has become a problem.

As methods for increasing the heat resistance and etching resistance of resists, methods of increasing the temperature stepwise during post-bake and heat treatment for a sufficient period of time, and methods of irradiating the resist pattern with ultraviolet rays after development or during post-bake are being considered. However, the former method has the disadvantage that sufficient heat resistance and etching resistance cannot be obtained and the processing time is significantly longer.

In the latter method, when a lamp that mainly emits only ultraviolet light, such as a low-pressure mercury lamp, is used, there are drawbacks such as low intensity, long processing time, and insufficient etching resistance. Furthermore, in the latter method, if a lamp such as a high-pressure mercury lamp that emits more elastic ultraviolet light is used, the processing time may be shorter (although the overall intensity of the emitted light is strong, so the wafer temperature may rise too much during irradiation). However, there was a drawback that the resist pattern deteriorated.

[Problem that the invention seeks to solve]

As described above, in conventional resist processing methods, even if some improvement in heat resistance and etching resistance can be achieved by UV irradiation after development or post-baking, the processing time becomes longer or There was a problem in that the temperature of the semiconductor wafer rose during irradiation and the resist pattern deteriorated. In other words, there was a problem in that the entire resist process could not be carried out organically and effectively. In view of these problems, the present invention organically combines synchrotron radiation with beta to perform resist processing. The purpose is to do so effectively.

[Means for solving problems]

In order to achieve this object, in the present invention, a resist applied to a semiconductor wafer is irradiated with synchrotron radiation from a high-pressure mercury lamp on a wafer processing table equipped with vacuum suction holes and a heating means. At the same time or after a predetermined time has elapsed when the wafer is vacuum-sucked onto the wafer processing table, radiation is applied, and further after a predetermined time, heating by the wafer processing table is started.

[For production]

In this invention, by organically combining resist processing by synchrotron radiation irradiation using a high-pressure mercury lamp containing strong ultraviolet rays with baking, etc., the time required for resist processing by synchrotron radiation irradiation is shortened and the resist processing capacity is increased. becomes possible. More specifically, in the present invention, resist processing by synchrotron radiation irradiation is effectively performed by heating the wafer on a wafer processing table after a predetermined period of time has elapsed from the start of synchrotron radiation irradiation. That is, if heating by the wafer processing table is started at the same time as synchrotron radiation irradiation, the temperature of the resist will rise rapidly.
There is a risk that the resist pattern will collapse. On the other hand, if only irradiation with synchrotron radiation is performed for a predetermined period of time, the heat resistance of the resist increases, so even if the temperature is increased by adding heating on a wafer processing table afterwards, the resist pattern will not collapse. That will no longer be the case.

(Example) FIG. 1 is a resist processing apparatus for explaining an embodiment of the resist processing method according to the present invention, and FIG. 2 is a diagram showing the temperature change of the resist in this resist processing method.

The wafer processing table 6 is heated via a heater lead wire 9 and cooled by cooling water 11 . In addition, the wafer processing table 6
A vacuum suction hole 7 is added, and it is possible to evacuate it with a vacuum pump. The irradiation part is a high pressure mercury lamp.1. It consists of a concave mirror 2 and a shutter 3, and the synchrotron radiation emitted from the high pressure mercury lamp 1 passes through the concave mirror 2.
etc., the resist 4 coated on the semiconductor wafer 5 is irradiated via the shutter 3.

Next, a method of performing resist processing using this resist processing apparatus will be described. A semiconductor wafer 5 coated with a resist 4 is placed on a wafer processing table 6. Next, by evacuating the vacuum suction hole 7, the semiconductor wafer 5 is brought into close contact with the wafer processing table 6. With the semiconductor wafer 5 in close contact with the wafer processing table 6, the shutter 3 is opened and the resist 4 is irradiated with synchrotron radiation emitted from the high-pressure mercury lamp 1.

In this state, the wafer processing table 6 is heated after a predetermined time has elapsed since the irradiation with the synchrotron radiation. After heating the wafer processing table 6 for a predetermined period of time, the heating is stopped (that is, the heater is turned off), and at the same time, or after a predetermined period of time has elapsed, cooling water 11 is flown to perform water cooling. Further, at the same time as the heater is turned off, or after a predetermined period of time has elapsed, the shutter 3 is closed to stop irradiation of synchrotron radiation. After stopping the irradiation and finishing the water cooling, the vacuum suction is released and the semiconductor wafer 5 coated with the resist that has been subjected to the ultraviolet treatment is removed from the wafer processing table 6.
A new semiconductor wafer is placed on the wafer processing table 6, and resist processing is performed in the same manner.

Here, to briefly explain FIG. 2, a.

Graphs b and c show synchrotron radiation irradiation and heating control of the wafer processing table (that is, control of heater current), respectively.

The temperature curve of the resist is shown. The dotted line in the graph a indicates the case where the shutter 3 is closed and synchrotron radiation irradiation is stopped after a predetermined time has elapsed since the heater was turned off. The dotted lines in the graphs b and c indicate the case where the cooling water 11 is flowed to perform water cooling after a predetermined time has elapsed since the heater was turned off. Furthermore, the temperature curve of the resist has a slight slope after the shutter 3 is opened until the heater is turned on.
This is because the resist 4 is warmed by the radiation.

In the above embodiments, the synchrotron radiation was turned on and off using a shutter, but instead of using the shutter, the synchrotron radiation was turned on and off by turning on and off a high-pressure mercury lamp.
Needless to say, it is also possible to turn it off.

Further, in order to select the wavelength of ultraviolet rays, it is also possible to provide a filter in addition to the concave mirror.

Further, the high-pressure mercury lamp may be one that emits ultraviolet rays of an appropriate wavelength, and it goes without saying that it may contain other metals in the form of halides or the like in addition to mercury.

[Effects of the Invention] As is clear from the above description, according to the present invention, by using a high-pressure mercury lamp that emits synchrotron radiation including strong ultraviolet rays, the time required for resist processing by ultraviolet irradiation can be shortened. This makes it possible to improve the heat resistance and etching resistance of the resist, thereby reducing damage to the resist film in subsequent processes.
Resist processing can be performed effectively.

[Brief explanation of drawings]

FIG. 1 is a resist processing apparatus for explaining an embodiment of the resist processing method according to the present invention, and FIG. 2 is a diagram showing the temperature change of the resist in this resist processing method. In the figure, 1: High-pressure mercury lamp 4: Resist 5: Semiconductor wafer 6: Wafer processing table agent Patent attorney 1) Kitatake Haru, negative for resist processing Figure 1 Tsugu Figure 2 Procedural Amendment (I) January 13, 1986 Day

Claims (1)

[Claims] On a wafer processing table with vacuum suction holes and heating means,
When irradiating the resist coated on the semiconductor wafer with synchrotron radiation from a high-pressure mercury lamp, the irradiation is performed at the same time as the semiconductor wafer is vacuum-adsorbed onto the wafer processing table, or after a predetermined period of time has elapsed, and then the irradiation is performed after a predetermined period of time has elapsed. A resist processing method characterized in that heating of the semiconductor wafer by the wafer processing table is then started.